PROLIFICATION.
Moquin-Tandon and other writers have classed the production of buds in
unwonted situations under the head of multiplication, but, as the
altered arrangement is of graver import than the mere increase in
number, it seems preferable to place these cases under this heading
rather than under that of alterations of number.
The adventitious bud may be a leaf-bud or a flower-bud; it may occupy
the centre of a flower, thus terminating the axis, or it may be axillary
to some or other of its component parts, or, again, it may be
extra-floral. In this last case the prolification is of the
inflorescence, and is hardly distinguishable from multiplication or
subdivision of the common flower-stalk. In accordance with these
differences we have median, axillary, and extra-floral prolification,
each admitting of subdivision into a leafy or a floral variety,
according to the nature of the adventitious bud. Under the head of each
variety certain special peculiarities are noticed, but it may here be
advisable to add a few general remarks on the subject.
Axillary prolification is a much less frequent malformation than the
median form. If only the number of orders and genera be reckoned, the
truth of this statement will be scarcely recognised; but if individual
cases could be estimated, the difference in frequency between the two
would be very much more obvious. This may, perhaps, be explained by the
fact that the branch has a greater tendency to grow in length than it
has to develop buds from the axils of the leaves. The flower is admitted
to be homologous with the branch, and it is also known that, up to a
certain time, the branch-bud or leaf-bud and the flower-bud do not
essentially differ.[104] At a later stage the difference between the two
is manifested, not only in the altered form of the lateral organs in the
flower-bud, but in the tendency to an arrest of growth, thus limiting
the length of the central axial portion. Now, in prolified flowers the
functions and, to a considerable extent, the appearance of a leaf-bud or
of a branch are assumed, and with them the tendency to grow in length is
developed. Median prolification, therefore, in this sense, is a further
step in retrograde metamorphosis than is the axillary form. To grow in
length, and to produce axillary buds, are alike attributes of the
branch; but the former is much more frequently called into play than the
latter; for the same reason, median prolification is more common than
the axillary form. This is borne out by the frequency with which
apostasis, or the separation of the floral whorls one from another, to a
greater degree than usual, is met with in prolified flowers.
In both forms the adventitious growth is much more frequently a
flower-bud or an inflorescence than a leaf-bud or a branch. This may be
due to the position of the flowers on a portion of the stem of the plant
especially devoted to the formation of flower-buds, to the more or less
complete exclusion of leaf-buds, _i.e._ on the inflorescence. This
conjecture is borne out by the comparative rarity with which
prolification has been observed in flowers that are solitary in the
axils of the ordinary leaves of the plant. If the lists of genera
appended hereto be perused, it will be seen that nearly all the cases
occur in genera where the inflorescence is distinctly separated from the
other branches of the stem. In direct proportion, then, to the degree in
which one region of the axis or certain branches of a plant are devoted
to the formation of flower-buds to the exclusion of leaf-buds, is the
frequency with which those flowers become affected with floral
prolification.
Flowers produced upon indefinite inflorescences are liable to be
affected with either form of prolification more frequently than those
borne upon definite inflorescences. Prolification in both varieties is
also more frequently met with in branched inflorescences than in those
in which the flowers are sessile; but the degree of branching seems less
material, inasmuch as this malformation is more commonly recorded as
occurring in racemes than in the more branched panicles, &c. From the
similar arrest of growth in length, in the case of the flower, to that
which occurs in the stem in the case of definite inflorescence, it might
have been expected that axillary prolification would be more frequent in
plants having a cymose arrangement of their flowers than in those whose
inflorescence is indefinite; such, however, is not the case. The reason
for this may be sought for in the lengthening of the floral axis, so
common in prolified flowers--a condition the reverse of that which
happens in the case of definite inflorescence.
Median prolification occurs frequently in double flowers; the axillary
variety, on the other hand, is most common in flowers whose lateral
organs have assumed more or less of the condition of leaves. The other
coincident changes are alluded to elsewhere or do not present useful
points of comparison, and may therefore be passed over.
=Prolification of the inflorescence.=--This consists in the formation of
leaf-buds or of an undue number of flower-buds on the inflorescence. It
must be distinguished from virescence, or the mere green colour of the
floral organs, and from chloranthy, in which all or the greater portion
of the parts of the flower are replaced by leaves. Prolification is, in
fact, a formation of supernumerary buds, leafy or floral, as the case
may be, these buds being sessile or stalked, the ordinary buds being not
necessarily changed. Prolification of the inflorescence, like the other
varieties, admits of subdivision, not only according to the foliar or
floral nature of the bud, but according to its position, terminal or
median and lateral.
Terminal prolification of the inflorescence, whether leafy or floral, is
hardly to be looked upon in the light of a malformation[105] seeing that
a similar condition is so commonly met with normally, as in _Epacris_,
_Metrosideros_, _Bromelia_, _Eucomis_, &c., wherein the leafy axis
projects beyond the inflorescence proper; or as in _Primula imperialis_,
in which plant, as also in luxuriant forms of _P. sinensis_, tier after
tier of flowers are placed in succession above the primary umbel.
Nevertheless, when we meet with such conditions in plants which, under
ordinary circumstances, do not manifest them, we must consider them as
coming under the domain of teratology.
=Median foliar prolification of the inflorescence= is frequently met
with in _Coniferae_, and has of late attracted unwonted attention from
the researches of Caspary, Baillon, and others, on the morphology of
these plants. The scales and bracts of the cone in these abnormal
specimens frequently afford transitional forms of the greatest value in
enabling morphologists to comprehend the real nature of the floral
structure. It would be irrelevant here to enter into this subject;
suffice it merely to say that an examination of very numerous specimens
of this kind, in the common larch and in _Cryptomeria Japonica_, has
enabled me to verify nearly the whole of Caspary's observations. A
similar prolongation of the axis occurred in some of the male catkins of
_Castanea vesca_, each of which had a tuft of small leaves at their
extremity. In the common marigold and in _Lotus corniculatus_ I have
also seen instances of this kind. Kirschleger[106] describes a tuft of
leaves as occurring on the apex of the flowering spike after the
maturation of the fruit in _Plantago_, and a similar growth frequently
takes place in the common wallflower, in _Antirrhinum majus_, &c. In
cases where a renewal of growth in the axis of inflorescence has taken
place after the ripening of the fruit, the French botanists use the term
recrudescence, but the growth in question by no means always occurs
after the ripening of the fruit, but frequently before. Professor Braun
cites the case of a specimen of _Plantago lanceolata_, in which the
spike was surmounted by a tuft of leaves and roots, as well as a still
more singular instance in _Eryngium viviparum_, in which not only did
particular branches terminate in rosettes of leaves provided with roots,
but similar growths proceeded from the heads of flowers themselves.
Baron de Melicoq[107] gives a case in _Primula variabilis_, in which at
the top of the flower-stalk, in the centre of six flowers, was placed a
complete plant in miniature, having three leaves, from the axil of one
of which proceeded a rudimentary flower. Mr. W. B. Jeffries also
forwarded me a polyanthus (fig. 52) in which the peduncle was surmounted
by a small plant, forming a crown above the ordinary flower-stalk, just
as the crown of the pineapple surmounts that fruit. A similar instance
was exhibited at the Scientific Committee of the Horticultural Society
on July 11th, 1868, by Mr. Wilson Saunders; the species in this case was
_P. cortusoides_. To Mr. R. Dean I am indebted for a similar proliferous
cyclamen, which seems similar to one mentioned by Schlechtendal.[108]
This author alludes to an analogous circumstance in the inflorescence of
_Cytisus nigricans_, where, however, the change was not so great as in
the preceding cases. The instances just cited all occur in plants having
an indefinite form of inflorescence; but the production of a tuft of
leaves or of a leafy shoot above or beyond the inflorescence is not
confined to plants with this habit of growth, for Jacquin figures and
describes an instance of this nature in the cymose flower-stems of a
Sempervivum. "_Hi racemi_," says he, "_ultra flores producuntur in
ramos, foliosos duo bifidos qui tandem trium unciarum longitudinem
adepti fuerunt_."[109]
[Illustration: FIG. 52.--Inflorescence of _Polyanthus_, bearing a tuft
of leaves at the top of the scape intermixed with the flowers.]
=Median floral prolification of the inflorescence=, wherein a new
inflorescence projects beyond the primary one, is not uncommon in plants
having their flowers arranged in close heads or umbels, as in the
common wild celery and other _Umbelliferae_.[110] I have also met with
it in _Trifolium repens_, in the umbellate variety of the common
primrose, and in the scarlet geranium. Engelmann cites it in _Triticum
repens_, Roeper in _Euphorbia palustris_.[111]
=Lateral foliar prolification of the inflorescence= is of more common
occurrence than the preceding. I have met with it, amongst other plants,
frequently in _Brassica oleracea_, _Pelargonium zonale_, SCABIOSA,
BELLIS, and many other composites, also in _Leguminosae_, e.g. _Lupinus_,
_Trifolium_, _Coronilla_, &c. Prof. Oliver forwarded me a specimen of
_Euphorbia geniculata_ in which, in addition to other changes, there was
a series of stalked buds bearing tufts of green scales, but without any
trace of stamens or pistil; these adventitious buds occurred within the
ordinary involucre of the plant, between it and the stamens. The pistil
was unaffected in some cases, while in some others it was entirely
wanting, the gynophore being surmounted by a cup-like involucre, divided
into three acutely pointed lobes, each with a midrib; these encircled a
series of stalked involucels, as before, and among which were scattered
a few stamens, some perfect, others partially frondescent.
In a specimen of _Scrophularia nodosa_ examined by me one of the lateral
buds on each of the cymes was represented, not by a flower, but by a
tuft of leaves, the other buds being unchanged. As the inflorescence was
much contracted in size, the appearance of the whole plant was greatly
changed.
Many of the instances of so-called viviparous plants, _e.g._, _Polygonum
viviparum_, may be cited under this head.[112] Many species of _Allium_,
_Lilium_, _Saxifraga_, _Begonia_, _Achimenes_, normally produce
leaf-buds or bulbs in the inflorescence; so, too, leafy shoots are
sometimes found in _Alisma natans_, _Juncus uliginosus_, _Chlorophytum
Sternbergianum_, &c. As an accidental occurrence, a similar thing has
been noticed in _Lychnis coronaria_, _Phaius grandifolius_, _Oncidium
cebolleta_, _Epidendrum elongatum_,[113] &c. &c.
Here, too, may be mentioned those cases wherein a leaf-bud is found upon
the surface of the so-called inferior ovary; generally a leaf only is
found, but a leaf-bud may also originate in this situation, and in
either case the inference is that the ovary is, in part at least, made
of the dilated and hollowed axis. Leaves may occasionally be found in
this way on the so-called calyx-tube or on the inferior ovaries of
roses, pears, apples, _Pereskia_, _Crataegus tanacetifolia_, &c.
The fruits of _Opuntia Salmania_ and of _O. fragilis_ ('Bull. Soc. Bot.
France,' vol. i, p. 306; vol. v, p. 115) have been observed to form
small fruit-like branches around their summits. This circumstance is
more fully treated of in the succeeding chapter relating to Heterotaxy.
=Lateral floral prolification of the inflorescence.=--This, which is
termed by Engelmann Ecblastesis foliorum sub floralium,[114] is much the
most common of all these deviations, and it is met with in every degree,
from the presence of a single supernumerary flower in the axil of a
bract to the existence of a small cluster or panicle of such flowers.
[Illustration: FIG. 53.--Lateral prolification in inflorescence of
_Pelargonium_.]
It is common in the _Anemone coronaria_ and _hortensis_, also in the
common scarlet _Pelargonium_ (fig. 53). It has been frequently recorded
in _Poterium sanguisorba_, and in _Sanguisorba officinalis_, and is
especially common in _Umbelliferae_, _Dipsacaceae_, and _Compositae_; a
familiar illustration in the latter order is afforded by the
hen-and-chicken daisy. In some species of Compositae, indeed, it is a
normal and constant occurrence, while in other cases, such as _Filago
germanica_, usually described as proliferous, there is not, strictly
speaking, any prolification, for the branching of the stalk takes place
below the inflorescence, and the branches originate from the axils of
ordinary leaves, not from the floral leaves or bracts. _Convolvulus
Sepium_ is very commonly subject to the production of flower-buds from
the axils of the floral leaves. The several species of Plantain
(_Plantago_) seem very liable to this and similar changes.
Schlechtendal[115] gives a summary of the various kinds of malformation
affecting the inflorescence in _Plantago_, and divides them into five
groups, as follows:--1st, bracteate, wherein the inferior bracts are
quite leaf-like, as is frequently seen in _Plantago major_. 2nd,
roseate; bracts leafy in tufts or rosettes, without flowers, as in the
so-called rose plantain, common in old-fashioned gardens in this
country. 3rd, polystachyate; spike-branched, bearing other spikes in the
axils of the bracts, as in _P. lanceolata_, _P. maritima_, &c. 4th,
proliferous, where the flower-stalk bears a rosette, a spike, or a head
with other rosettes. 5th, paniculate, in which the inflorescence has
become a much-branched pyramidal panicle, covered with little bracts,
and with very rudimentary flowers.[116] The first two groups belong
rather to frondescence of the bracts; but with regard to the whole of
them it will easily be surmised that intermediate forms occur, linking
one group to the other, and defying exact allocation in either. Thus, in
the borders of richly cultivated fields in the neighbourhood of London I
have frequently gathered specimens of _Plantago major_ with a branched
spike provided with large leafy bracts, the branches of the spike being
but little less in diameter than the ordinary single spike. These
specimens would therefore seem to be intermediate between
Schlechtendal's bracteate and polystachyate divisions. Wigand[117] also
describes an anomalous specimen of _Plantago major_ similar to those
just mentioned, but having small lateral spikes in place of large ones.
The instance quoted from Professor Braun would fall under the roseate
section, as would also that of Kirschleger, though we are expressly told
that the tuft of leaves in this last case was not developed until after
the ripening of the seed-vessel. One of the characters of the roseate
group, according to Schlechtendal, is the absence of flowers, but most
persons who have had the opportunity of watching the growth of the rose
plantain must have observed the occasional production of flowers,
sometimes stalked, in the axils of the leafy bracts, and at the same
time have noticed that the internodes become elongated, so that an
approach is made to the ordinary spike-like form of the inflorescence.
The proliferous group would include such specimens as that of _P.
lanceolata_ mentioned by Dr. Johnston,[118] wherein were several
spikes, some sessile, others stalked and pendent, the whole intermixed
with leaves and disposed in a rose-like manner. I have myself gathered
specimens of this nature, occurring in the same plant, at Shanklin, Isle
of Wight (fig. 56).
[Illustration: FIG. 54.--_Plantago major_, with panicled inflorescence.]
[Illustration: FIG. 55.--Inflorescence of _Plantago major_, with bracts
partly replaced by leaves and spike branched.]
[Illustration: FIG. 56.--Inflorescence of _Plantago lanceolata_, bearing
a tuft of leaves and flowers at the end of the flower-scape.]
It is rather singular that each species of _Plantago_ seems to have its
own perverse mode of growth; for instance, the bracteate, polystachyate
and paniculate forms are almost exclusively confined to _P. major_, the
roseate form to _P. media_, the proliferous form to _P. lanceolata_.
The instances wherein flower-buds originate from the surface of an
inferior ovary, as in those cases where the top of the stem is dilated
so as to form part of the fruit, would be properly classed under the
head of prolification of the inflorescence. As, however, there is still
some difference of opinion as to the correct morphological
interpretation to be put on some of these cases, it has been thought
better to include them under the head of heterotaxy than of
prolification.
[Illustration: FIG. 57.--Branched inflorescence of _Reseda luteola_.]
Some of the cases of prolification of the inflorescence resulting in a
branching of an ordinarily simple inflorescence, as in _Reseda luteola_
(fig. 57), might equally well be placed with fission or multiplication
of the axile organs. Branched spikes of this character are not so common
among Orchids as might be expected. Professor Reichenbach enumerates a
few instances in the Report of the International Botanical Congress of
London, 1866, p. 121, and the same author gives an illustration in his
'Orchidographia Europoea,' tab. 150.
In Grasses, as indeed in other plants with a spicate inflorescence, this
change occurs not unfrequently. The common Ray Grass (_Lolium_) is
especially subject to the change in question, and among cultivated
cereals, maize and wheat occasionally show this tendency to subdivision.
One variety of the latter grain is cultivated in hot countries under the
name of Egyptian wheat--_Triticum vulgare_, var. _compositum_.
Prolification of the inflorescence has been most frequently observed in
the following genera:
_Leafy_. _Floral_.
Ranunculaceae Ranunculus. Ranunculus!
Anemone. Anemone.
Cruciferae. *Brassica!
Caryophyllaceae. Lychnis!
Dianthus!
Geraniaceae. *Pelargonium! *Pelargonium!
Leguminosae. *Trifolium! Trifolium!
Lotus! Lotus!
Coronilla!
Cytisus. Cytisus.
Rosaceae. Poterium.
*Pyrus! *Pyrus!
*Crataegus! Crataegus!
*Rosa. Rosa!
Sanguisorba.
Philadelphaceae. Philadelphus.
Crassulaceae. Sempervivum.
Echeveria.
Crassula.
Ficoideae. ?Tetragonia.
Cactaceae. Opuntia. Opuntia.
Pereskia.
Saxifragaceae. Saxifraga!
Umbelliferae. Seseli.
*Apium!
Cnidium.
Chaerophyllum.
Eryngium. Eryngium.
Silaus.
Heracleum! Heracleum!
Hydrocotyle. Hydrocotyle.
Daucus.
Carum.
Selinum.
Angelica!
Conium.
Astrantia.
OEnanthe. OEnanthe.
Begoniaceae. Begonia!
Valerianaceae. Valeriana.
Dipsacaceae. *Scabiosa! *Scabiosa!
Knautia! Knautia!
Compositae. *Bellis!
Centaurea.
Calendula. Calendula.
Anthemis.
Coreopsis.
Apargia.
Lampsana.
Carlina.
Arnoseris.
Tragopogon! Tragopogon!
Rudbeckia!
Senecio!
Carlina.
Bidens! Pyrethrum.
Filago.
Hedypnois.
Cirsium.
Lactuca.
Campanulaceae. Prismatocarpus.
Lobeliaceae. Jasione.
Ericaceae. Azalea!
Convolvulaceae. Convolvulus! Convolvulus!
Calystegia!
Scrophulariaceae. Scrophularia!
Antirrhinum!
Gesneraceae. Achimenes!
Primulaceae. Primula! Primula!
Cyclamen! Cyclamen!
Plumbaginaceae. Armeria.
Plantaginaceae. *Plantago! *Plantago!
Polygonaceae. Polygonum!
Euphorbiaceae. Euphorbia!
Urticaceae. Ficus.
Amentaceae. Corylus!
Castanea! Castanea.
Coniferae. *Larix!
*Cryptomeria!
Taxodium! Pinus.
Orchidaceae. Phaius! Ophrys!
Epidendrum!
Oncidium!
Liliaceae. *Allium!
*Ornithogalum!
*Lilium!
Amaryllidaceae. Fourcroya
Alismaceae. Alisma!
Palmaceae. Cocos.
Juncaceae. *Juncus!
Restiaceae. Restio! Restio!
Elegia! Elegia!
Willdenovia! Willdenovia!
Cyperaceae. Carex.
Graminaceae. Dactylis.
*Lolium!
Festuca.
*Zea!
*Triticum!
*Hordeum!
Secale.
Phleum.
In addition to the papers already cited the following works may be
consulted with reference to prolification of the inflorescence:
Moquin-Tandon. 'El. Ter. Veg.,' p. 376. Engelmann, 'De
Antholysi,' Secs. 85-87. Fleischer, 'Missbild. Versch. Cultur.
Pflanz.' For figures of Hen and Chicken Daisy (_Bellis
prolifera_). see Lobel, 'Ic.,' 477. Sweert, 'Florileg.,' pl.
98, f. 5. 'Hort. Eystett. Plant. Vern.,' fol. iv, f. i. &c. For
similar malformations in marigold (_Calendula_), see Lobel,
'Ic.,' 553. 'Act. Acad. Nat. Cur.,' vol. x, p. 208. Jaeger,
'Missbilld.,' 192-195. 'Hort. Eystett.,' pl. aestiv. fol. iii,
f. i. Klinsmann, 'Linnaea,' t. x, p. 607.
For monstrous plantains, in addition to previous citations, see
Camerarius, 'Epist.,' p. 261, _P. rosea_. Matthioli,
'Krauterb,' 245. Lobel, 'Stirp. Advers. Nov.,' p. 128, _P.
major paniculata._ J. Bauhin, 'Hist. Plant.,' i, p. 503 _b_.
Ibid., p. 503, _a_, _c_, _P. major rosea_, _bracteata
paniculata_, _prolifera_, &c. 'Hort. Eystett.,' pl. aestiv., t.
vii, f. 2, _P. rosea_ et _P. bracteata_. Lobel, 'Stirp. Hist.,'
p. 162. Dodonaeus, 'Pempt.,' 1-4, cap. xxiii, P. major spica
multiplex, _i.e._ paniculata. Gerard, 'Herbal.' Clusius,
'Plant. Rar. Hist.,' lib. v, p. 109-10, _Plantago augustifolia
Gareti prolifera_. Marchand, 'Adansonia,' iv, p. 156.
_Coniferae._--Richard, 'Mem. Conif.,' tab. xiii, f. 9. A. Braun,
'Das Individ.,' 1853, p. 65. De Cand., 'Organogr.,' tab. xxxvi.
Wigand, 'Bot. Untersuch.,' 154. Schlechtendal, 'Bot. Zeit.,'
1859, p. 239. Caspary, 'De Abiet. flor. fem. struct. morphol.'
Parlatore, 'Ann. Sc. Nat.,' 1862, vol. xvi, p. 215. Cramer,
'Bildungsabweich.,' p. 4, &c., &c.
_Gramineae._--Bauhin, 'Pinax.,' 21. Morison, 'Hist. Plant.,' t.
i. Winckler, 'Ephem. Nat. Cur.,' dec. i, ann. 7, 8, p. 151.
Irmisch, 'Flora,' 1858, p. 40, &c.
See also under Chloranthy, Viviparous plants, &c.
=Prolification of the flower.=--In the preceding sections the formation
of adventitious buds of a leafy or floral nature on the inflorescence
has been considered. A similar production of buds may take place in the
flower itself, either from its centre or from the axil of some of its
constituent parts. Prolification of the flower is therefore median or
axillary, and the adventitious bud itself may be of a leafy or a floral
nature.
=Median leafy prolification.=--In this malformation the centre of the
flower is occupied by a bud or a branch; the growing point or
termination of the axis which ordinarily ceases to grow after the
formation of the carpels, takes on new growth. This is well shown in the
accompanying illustration (fig. 58), representing the thalamus of a
strawberry prolonged beyond the fruits into a small leaf-bearing branch.
[Illustration: FIG. 58.--Receptacle of strawberry prolonged into a leafy
branch. From the 'American Agriculturist.']
[Illustration: FIG. 59.--Flower of _Verbascum_ with five disunited
sepals, five similar green petals, and a prolonged branch in the centre
of the flower.]
In other cases the carpels are entirely absent and their place is
supplied by a leafy shoot as in a species of _Verbascum_, which came
under my own observation. In this case the petals were virescent, and
the stamens and pistils were entirely absent, hence in truth, the
so-called flower more nearly resembled a branch. In a flower of a May
Duke cherry, for which I am indebted to Mr. Salter, there was a gradual
change from the floral to the foliar condition; thus there were five
distinct lanceolate sepals, the arrangement of whose veins betokened
that they were leaf-sheaths rather than perfect leaves, ten petals
partly foliaceous and sheath-like as to their venation, one of them
funnel-shaped, but whether from dilatation or cohesion of the margins
could not be determined. The stamens were eight or ten in number, their
connectives prolonged into foliaceous or petaloid appendages, so that
the filament represented the stalk of the leaf. The pistil was entirely
absent and its place was supplied by a branch with numerous perfectly
formed stipulate leaves.
Some flowers of _Anagallis arvensis_ described by Dr. Marchand[119] are
so interesting and show so well the gradual stages by which this
malformation is arrived at, that it is desirable to cite the summary of
Dr. Marchand's researches as given in the 'Gardeners' Chronicle' by Mr.
Berkeley, taking that instance first in which the parts of the flower
departed least from the normal condition, and then the others in their
proper order. In all the parts there was a greater or less tendency to
assume a green tint; in some they were entirely green, in others the
brighter colours were confined to the more recently developed parts.
"1. In the first case then, the sepals and petals were in their normal
position, though rather more dilated than usual; the anthers were
fertile, the principal change existing in the ovary, the upper part of
which was wanting, so that the ovules were exposed seated on the central
placenta.
2. In the next step the calyx, more developed than usual, was separated
from the corolla by a long peduncle, and the ovary, which was ovate,
contained instead of a placenta a sort of plumule or young shoot.
3. In this case the corolla and calyx were distant from each other;
there was no trace of stamens, but the axis was continued from the
centre of the corolla, and ended in a leaf-bud.
4. The calyx and corolla nearly as before, but instead of stamens a
whorl of little leaves was developed, in the centre of which the axis
was continued, bearing at its tip two whorls of leaflets, alternately
three and three.
5. In this case two out of the five stamens were normal, the other three
changed into leaves, showing clearly the origin of the leaflets, in the
last case, which took the place of the stamens.
6. The ovary varied in different flowers. In some the placenta was
crowned with ovules; in others the ovules were replaced by a single
whorl of leaflets; in others there was every shade of change from
ordinary ovules to perfect leaflets; while in others, again, every ovule
was converted into a leaf with a long petiole.
7. In these flowers shoots were developed in the axils of the sepals, or
on the face of the petals between the point of their insertion and that
of the stamens, and, what is most curious, in the interior of the
ovaries round the foot of the placenta.
8. Here, again, a very singular condition presented itself: the calyx
and corolla separated from each other, the stamens partly developed, the
axis continued beyond the corolla, branched and bearing normal leaves so
as exactly to resemble an ordinary stem, while in consequence of the
calyx and corolla being bent down to the ground, adventitious roots were
developed from the axis on the under side above each of them. In another
case, where the calyx and corolla were approximated, the ovary was open
above, and sent out six shoots from within, perfectly developed, clearly
representing the central placenta and five axile buds, and each giving
out a number of adventitious roots at its base."
In other genera of the same order (_Primulaceae_) an extension of the
placenta into a leafy branch has been observed, as in _Lysimachia_,
where in one case the prolonged placenta was removed and struck as a
cutting.[120]
In _Ericaceae_ too, the axile placenta has been seen ovuliferous at the
base and prolonged above into a leafy branch.[121]
=Median floral prolification.=--This is of more frequent occurrence than
the preceding. The prolonged axis is more frequently terminated by a
flower-bud than by a leaf-bud, though it must be remarked, that the
lengthened and protruded stem frequently bears leaves upon its sides,
even if it terminate in a flower, and thus the new growth partakes of a
mixed leafy and floral nature. Instances of this kind have long been
familiar to observers, and have always excited attention from the
singularity of their appearance. In one of the old stained-glass
windows, apparently of Dutch manufacture, in the Bodleian Picture
Gallery at Oxford, is a representation of a _Ranunculus_ affected with
median floral prolification.[122] In pinks the affection is not
unfrequently met with. Fig. 60 shows an instance of the kind copied from
Schotterbec.
A singular instance of prolification in the central flower of one of the
verticillasters of _Phlomis fruticosa_ fell under my own notice; it was
a case wherein the calyx was torn on one side, and one of its lobes had
become petaloid. Between the calyx and the corolla were three or four
spathulate, hairy, bract-like organs; the corolla and stamens were
unchanged; but in place of the usual four-lobed ovary there was a single
carpel with a basilar style, terminated by a forked stigma. Occupying
the place of the other lobes of the pistil was an oblong woolly
flower-bud, consisting of calyx, corolla, and stamens, but with no trace
of pistil. I have been unable to find recorded any instance of
malformation among Labiates or Borages at all similar to this. It
differed from most other examples of prolification in that the axis was
not prolonged, the adventitious bud occupying precisely the position of
the three lobes of the ovary that were absent. The sole remaining carpel
had a style and a stigma as perfect in appearance as though the pistil
had been complete.
[Illustration: FIG. 60.--Flower of _Dianthus_ affected with median
floral prolification.]
In a flower of _Conostephium_ (_Epacridaceae_) forwarded to me by Mr.
Bentham, there was a similar adventitious bud placed by the side of the
pistil, but as the latter contained the usual number of cells it is
probable that the supernumerary bud in this case originated rather from
the side than the end of the axis.
Certain families of plants present this deviation from their ordinary
structure with greater frequency than others: the following orders seem
to be the most frequently affected by it: _Ranunculaceae_,
_Caryophyllaceae_, _Rosaceae_; while it is commonly met with in
_Scrophulariaceae_, _Primulaceae_ and _Umbelliferae_. Of genera which seem
peculiarly liable to it may be mentioned the following: _Anemone_,
_Ranunculus_, _Cheiranthus_, _Dianthus_, _Dictamnus_, _Daucus_, _Rosa_,
_Geum_, _Pyrus_, _Trifolium_, _Antirrhinum_, _Digitalis_, _Primula_.
A reference to the subjoined list of genera affected by this
malformation, and the knowledge of its comparatively greater frequency
in some than in others of them, will show that it is more often met with
in plants having an indefinite form of inflorescence than in those
having a definite one. The change may affect some only, or the whole of
the flowers constituting an inflorescence; and though it is by no means
a constant occurrence, it very frequently happens that the central or
terminal flower in a definite inflorescence is alone affected, the
others remaining in their ordinary condition, as in pinks (_Dianthus_);
and in the indefinite forms of inflorescence, it is equally common that
the uppermost flower or flowers are the most liable to be thus affected.
In those plants which present this deviation from the ordinary condition
with the greatest frequency, it often happens that the axis is normally
more or less prolonged, either between the various whorls of the flower,
as in the case of the gynophore, &c., or into the cavity of the carpels,
as in the instances of free central placentation. To bear out this
assertion, the following instances taken from those genera having
definite inflorescence, and which are very commonly affected with
prolification, may be cited; thus, in _Anemone_ and _Ranunculus_ the
thalamus is prolonged to bear the numerous carpels; in _Dianthus_ there
is a marked internode separating the carpels from the other parts of the
flower; in _Primulaceae_ central prolification is very common, and this
is one of the orders where the placenta seems from the researches of
Duchartre and others, to be truly a production of the axis within the
carpels;[123] in _Thesium_ also, another genus with free central
placenta, this malformation has been found.
So also among plants with indefinite inflorescence, prolification seems
very frequently to affect those wherein the axis is normally prolonged;
thus it is common in _Dictamnus_, which plant has an internode
supporting the pistil; it is frequent among _Umbelliferae_, where the
carpophore may be truly considered an axile production; it is common
among _Rosaceae_ and _Ranunculaceae_, in many of which the axis or
thalamus is well-marked, and it is by no means infrequent in the flowers
of the Orange, where the floral internodes are also slightly elongated;
on the other hand, there is no case on record in _Magnoliaceae_, and some
other orders where the floral part of the axis is at some point or other
elongated; still, on the whole, there can be but little doubt that there
is a real relation between prolification and the normal extension of the
floral internodes.
Under these circumstances, those instances wherein the parts of the
flower become separated one from the other by the elongation of the
internodes (apostatis), constitute a lesser degree of the same change,
which operates most completely in the formation of a new bud at the
extremity of the prolonged axis. Some specimens of _Geum rivale_ (a
plant very liable to become prolified) in my possession show this very
clearly. In the wild plant the thalamus is elevated on a short stalk; in
the abnormal ones the thalamus is simply upon a longer stalk than usual,
or in a more advanced stage of the deviation the lengthened thalamus
takes the form of a branch provided with leaves and terminated by a
flower; it is noticeable, also, in these specimens, that the sepals of
the lower flower have assumed entirely the dimensions and appearance of
leaves.
Median prolification has occasionally been recorded in flowers that
have, in their ordinary condition, but one carpel, as in _Leguminosae_
and in _Santalaceae_. In _Leguminosae_, as also in _Amygdalus_, it would
seem as if the adventitious bud were strictly a lateral and axillary
production, and moreover that the carpel itself is not strictly terminal
but lateral in position, though apparently terminal from the abortion of
other carpels. In the only recorded instance that I am aware of, of this
malformation affecting the genus _Thesium_, the pistil was altogether
absent, and occupying its place was the new bud or branch.[124]
[Illustration: FIG. 61.--_Daucus Carota_, showing leafly carpels,
prolification, &c.]
As the carpels are not unfrequently absent in cases of median
prolification, it has been thought that the pistil in such cases was
metamorphosed into a stem bearing leaves or flowers. Setting aside the
physiological difficulties in the way of accepting such an opinion, an
examination of any number of cases is sufficient to refute it; for, as
Moquin well remarks, the carpels may frequently be found either in an
unaltered condition or more or less modified.
If the pistil be normally syncarpous, its constituent carpels, if
present at all in the prolified flower, become disjoined one from the
other to allow of the passage between them of the prolonged axis; thus
in some malformed flowers of _Daucus Carota_ gathered in Switzerland
(fig. 61), not only was the calyx partially detached from the pistil,
but the carpels themselves were leaf-like, disjoined, and unprovided
with ovules; between them rose a central prolongation of the axis, which
almost immediately divided into two branches, each terminated by a small
umbel of perfect flowers, surrounded by minute bracts.[125]
Not only are the carpels thus frequently separated one from the other by
the prolonged axis, but they undergo commonly a still further change in
becoming more or less completely foliaceous, as in the _Daucus_ just
mentioned, where the carpels were prolonged into two lance-shaped
leaves, whose margins in some cases were slightly incurved at the apex,
forcibly calling to mind the long "beaks" that some Umbelliferous genera
have terminating their fruits--for instance, _Scandix_. Dr. Norman, in
the fourth series of the 'Annales des Sciences,' vol. ix, has described
a prolification of the flower of _Anchusa ochroleuca_, in which the
pistil consisted of two leaves, situated antero-posteriorly on a long
internode, with a small terminal flower-bud between them; and numerous
similar instances might be cited.
In this place may also be noticed those instances wherein the placenta
elongates so much that the pericarp becomes ruptured to allow of the
protrusion of the placenta, although this prolongation is not attended
by the formation of new buds. Cases of this kind occurring in
_Melastoma_ and _Solanum_ have been put on record by M. Alph. de
Candolle.[126] This is a change analogous with that which occurs in some
species of _Leontice_ or _Caulophyllum_, as commented on by Robert
Brown. See 'Miscellaneous Botanical Works' of this author, Ray Society,
vol. i, p. 359.
If the pistil be apocarpous, and the carpels arranged spirally on an
elevated thalamus, it then frequently happens that the carpels,
especially the upper ones, become carried up with the prolonged axis,
more widely separated one from the other than below, and particularly
liable to undergo various petalloid or foliaceous changes as in
proliferous _Roses_, _Potentilla_, &c.
[Illustration: FIG. 62.--Median floral prolification, &c., in flower of
_Delphinium_.]
Fig. 62, copied from Cramer, shows an instance of this kind in
_Delphinium elatum_, where not only is the thalamus prolonged, and the
carpels separated, but from the axils of some of the latter which have
assumed from the disunion of their margins somewhat of the appearance of
leaves, other flowering branches proceed--axillary prolification. If, on
the other hand, the carpels be few in number, and placed in a
verticillate manner, the axis then generally passes upwards without any
change in the form or position of the carpels being apparent, as in a
proliferous columbine, figured in the 'Linnean Transactions,' vol.
xxiii, tab. 34, fig. 5.
When a flower with the ovary naturally inferior or adherent to the calyx
becomes prolified, a change in the relative position of the calyx and
ovary almost necessarily takes place, the latter becoming superior or
detached from the calyx; this has been already alluded to in
_Umbelliferae_. In a species of _Campanula_ examined by me, the calyx was
free, the corolla double, the stamens with petaloid filaments, and in
the place of the pistil there was a bud consisting of several series of
green bracts, arranged in threes, and enclosing quite in the centre
three carpellary leaves detached from one another and the other parts of
the flower, and open along their margins, where the ovules were placed.
In other similar instances in the same species of _Campanula_, the
styles were present, forming below an imperfect tube which surrounded
the adventitious bud; in another, contrary to what occurs usually in
such cases, the ovary was present in its usual position, but surmounted
by a bud of leafy scales, enclosed within the base of a tube formed by
the union of the styles. A similar relative change in the position of
the calyx and the ovary takes place when the _Compositae_ are affected
with central prolification, or even in that lesser degree of change
which merely consists in the separation and disunion of the parts of the
flower, but which in these flowers appear to be, as it were, the first
stage towards prolification. I owe to the kindness of Professor Oliver a
sketch of a species of _Rudbeckia_? showing this detachment of the calyx
from the ovary. In a monstrous _Fuchsia_ that I have had the opportunity
of recently examining, the calyx was similarly detached from the ovary
simultaneously with the extension of the axis. Here the petals were
increased in number and variously modified, the stamens also; while in
the centre and at the top of the flower, conjoined at the base with some
imperfect stamens, was a carpel open along its ovuliferous margins. Such
instances as these seem to be the first stages of a change which,
carried out more perfectly, would result in the formation of a new bud
on the extremity of the prolonged axis.
In _Orchidaceae_, among which family I have now met with several
instances of prolification, the ovary seems usually to be absent. Fig.
63 shows a prolified flower of _Orchis pyramidalis_ in which the
perianth was nearly regular, the central portions of the flower absent,
and their place supplied by a new miniature raceme. This specimen was
forwarded to me by Dr. Moore, of Glasnevin.
[Illustration: FIG. 63.--Median prolification in _Orchis pyramidalis_,
the outer segments of the perianth regular and reflexed.]
As might be expected, it very rarely happens that median prolification
occurs without some other deviation in one or more parts of the flower
being simultaneously manifested. Some of these changes have been already
mentioned, but others are commonly met with, as, for instance, the
multiplication or doubling, as it is termed, of the petals; others,
though less frequent, are of more interest. Fusion of two or more
flowers in association with prolification is especially common in
cultivated specimens of _Digitalis purpurea_; the uppermost flowers of
the raceme become fused together so as to form one large, regular,
erect, cup-shaped corolla, to the tube of which the stamens are
attached, in greater number than ordinary, and all of equal length; the
bracts and sepals are confusedly arranged on the exterior of the flower;
while in the centre, in the place usually occupied by the pistil, there
rises a conical prolongation of the axis, bearing at its outer or lower
portion a number of open carpels, provided, it may be, with styles and
ovules; these enclose an inner series of scale-like bracts, from whose
axils proceed more or less perfect florets; so that in the most highly
developed stage a perfect raceme of flowers may be seen to spring from
the centre of a cup-shaped regular flower, whose lobes show its compound
character. All intermediate stages of this malformation may be found
from cases where there is a simple fusion of two flowers with a second
verticil of carpels within the outer, up to such cases as those which
have been just mentioned. It is worthy of special remark, that in all
these cases the flowers at the uppermost part of the raceme are alone
affected, and that, in addition to the prolification, there is fusion of
two or more flowers, and regularity in the form of the compound corolla
and stamens.
The calyx of a prolified flower is either unchanged, or it is modified
in harmony with the changes in the central part of the flower. If the
ovary be normally superior or free from the calyx, then the latter is
comparatively rarely altered; for instance, in proliferous pinks
(_Dianthus_) the calyx is seldom affected, except, indeed, in those
instances where the floral axis is prolonged, and produces from its side
a successive series of sepals, as in what is called the wheat-ear
carnation; but though these instances may be, as I believe, an imperfect
degree of prolification, they do not affect the general truth of the
above opinion, that the calyx, if it be free from the ovary, is but
rarely changed in a prolified flower; but that this is not a universal
rule is shown by proliferous flowers of _Geum rivale_, where the sepals
are usually large and leaf-like, as they likewise are frequently in
proliferous roses and pears.
[Illustration: FIG. 64.--Proliferous rose. Hip absent, sepals leafy,
stamens wanting, axis prolonged bearing supplementary flower, &c. (Bell
Salter).]
Proliferous roses have a special interest, inasmuch as they show very
conclusively that the so-called calyx-tube of these plants is merely a
concave and inverted thalamus, which, in prolified specimens, becomes
elongated (fig. 64) after the fashion of _Geum rivale_, &c.[127]
Occasionally from the middle of the outer surface of the urn-shaped
thalamus proceeds a perfect leaf, which could hardly be produced from
the united sepals or calyx-tube; a similar occurrence in a pear is
figured in Keith's 'Physiological Botany,' plate ix, fig. 12.
The change which the calyx undergoes when flowers with an habitually
adherent ovary become prolified, and wherein the calyx is disjoined from
the ovary, has been before mentioned, but it may also be stated that,
under such circumstances, the constituent sepals are frequently
separated one from the other, and not rarely assume more or less of the
appearance of leaves, as in proliferous flowers of _Umbelliferae_,
_Campanulaceae_, _Compositae_, &c.
As to the corolla, it was long since noticed that prolification was
especially liable to occur in double flowers; indeed, Dr. Hill, who
published a treatise on this subject, setting forth the method of
artificially producing prolified flowers, deemed the doubling to be an
almost necessary precursor of prolification;[128] but, though frequently
so, it is not invariably the case that the flower so affected is
double--_e.g._ _Geum_. If double, the doubling may arise from actual
multiplication of the petals, or from the substitution of petals for
stamens and pistils, according to the particular plant affected.
Occasionally in prolified flowers the parts of the corolla, like those
of the calyx, become foliaceous, and in the case of proliferous pears
fleshy and succulent. There is in cultivation a kind of _Cheiranthus_?
in which there is a constant repetition of the calyx and corolla,
conjoined with an entire absence of the stamens and pistils; a short
internode separates each flower from the one above it, and thus
frequently ten or a dozen of these imperfect flowers may be seen on the
end of a flower-stalk, giving an appearance as if they were strung like
beads, at regular intervals, on a common stalk. I have seen a similar
instance in a less degree in a species of _Helianthemum_.
The stamens are subject to various changes in prolified flowers; they
assume, for instance, a leaf-like or petal-like condition, or take on
them more or less of a carpellary form, or they may be entirely absent;
but none of these changes seem to be at all necessarily connected with
the proliferous state of the flower. Of more interest is the alteration
in the position of these organs which sometimes necessarily accrues from
the elongation of the axis and the disjunction of the calyx; thus, in
proliferous roses the stamens become strictly hypogynous, instead of
remaining perigynous. In _Umbelliferae_ the epigynous condition is
changed for the perigynous, &c.
The condition of the pistillary organs in prolified flowers has already
been alluded to. Hitherto those instances have been considered in which
either the carpels were absent, or the new bud proceeded from between
the carpels. There is also an interesting class of cases where the
prolification is strictly intra-carpellary; the axis is so slightly
prolonged that it does not protrude beyond the carpels, does not
separate them in any way, but is wholly enclosed within their cavity.
Doubtless, in many cases, this is merely a less perfect development of
that change in which the axis protrudes beyond the carpels. This
intra-carpellary prolification occurs most frequently in plants having a
free central placenta, though it is not confined to them, as it is
recorded among _Boragineae_. A remarkable instance of this is described
by Mr. H. C. Watson in the first volume of Henfrey's 'Botanical
Gazette,' p. 88. In this specimen a raceme of small flowers was included
within the enlarged pericarp of a species of _Anchusa_. But the most
curious instances of this form of prolification are, no doubt, those
which are met with among _Primulaceae_ and other orders with free central
placentation.
Duchartre, in his memoir on the organogeny of plants with a free central
placenta, in the 'Ann. des Sc. Nat.,' 3 ser., 1844, p. 290, among other
similar instances, mentions two flowers of _Cortusa Matthioli_, wherein
the placenta was ovuliferous at the base; but the upper portion, instead
of simply elongating itself into a sterile cone, had produced a little
flower with its parts slightly different from those of the normal
flowers. M. Alph. de Candolle has likewise described somewhat similar
deviations, and one in particular in _Primula Auricula_, where the
elongated placenta gave off long and dilated funiculi bearing ovules,
while other funiculi were destitute of these bodies, but were much
dilated and foliaceous in appearance.[129] In some flowers of
_Rhododendron_ I have observed a similar condition of the ovules, which,
moreover, in the primary flowers, were attached to the walls of the
carpels--parietal placentation.
In speaking of these as cases of intra-carpellary prolification, it is,
of course, impossible to overlook the fact that they differ in degree
only from those cases where the lengthened axis projects beyond the
cavity of the carpels; nevertheless they seem to demand special notice,
because in these particular plants the placenta or its prolongation
appears never to protrude beyond the carpels, or at least very rarely.
There are, however, numerous instances of such an extension of the
placenta and of prolification occurring among _Primulaceae_ in
conjunction with the more or less complete arrest of growth of the
carpels.[130] An instance of this kind has come under my own notice in a
monstrosity of the chinese primrose, in which the carpels were reduced
to a hardly discernible rim surrounding an umbel of five rays, each
terminated by a small normally constituted flower-bud.
The ovules of a prolified flower are either unaffected, or they occur in
a rudimentary form, or, lastly, they may be present in the guise of
small leaves.
Under the term prolification of the fruit two or three distinct kinds of
malformation appear to have been included. The term seems usually to be
applied to those cases where from the centre of one fruit a branch
bearing leaves, flowers, or another fruit, is seen to project, as
happens occasionally in pears. Now, in many instances, not only the
fruit, is repeated, but also the outer portions of the flower, which
wither and fall away as the adventitious fruit ripens; so that at length
the phenomenon of one fruit projecting from another is produced. It is
obvious that this form of prolification in no wise differs from ordinary
central prolification. Sometimes some of the whorls of the adventitious
flower are suppressed; thus, M. Duchartre describes some orange blossoms
as presenting alternating series of stamens and pistils one above
another, while the calyces and corollas belonging to each series of
stamens and pistils were entirely suppressed.[131] In other cases,
doubtless, the carpellary whorl is alone repeated, the other whorls of
the adventitious flower being completely absent.
Another condition, apparently sometimes mistaken for prolification of
the fruit, is that in which the carpellary whorl becomes multiplied; so
that there is a second or even a third series within the outer whorl of
carpels. If the axis be at all prolonged, then these whorls are
separated one from the other, and produce in this way an appearance of
prolification. This happens frequently in oranges, as in the variety
called Mellarose.[132]
Moquin has given an explanation of the St. Valery Apples, wherein the
petals are sepaloid, the stamens absent, and where there is a double row
of carpels, by supposing these peculiarities to be due to "a
prolification combined with penetration and fusion of two or more
flowers," but it is surely more reasonable to conceive a second row of
carpels placed above the first by the prolongation of the central part
of the axis. Supposing this view to be correct, the inner calyx-like
whorl might be considered either as a repetition of the calycine whorl,
or it might be inferred that the corolla was present in the guise of a
second calyx.
Moquin-Tandon suggests another explanation--namely, that though the
stamens are absent in these curious flowers, at least in their ordinary
shape, they are represented by the lower row of carpels, which become,
in process of development, fused with the upper or true carpels. If this
were so, surely some intermediate conditions between stamen and carpel
would occasionally be present; but such does not appear to be the
case.[133]
In some of the instances of so-called proliferous pears the carpels
would seem to be entirely absent, and the dilated portion of the axis to
be alone repeated. Thus, the axis dilates to form the lower fruit
without any true carpels being produced, but at its summit a whorl of
leaves (sepals) is formed; above these another swelling of the axis
takes place also without the formation of carpels, and this, it may be,
is terminated in its turn by a branch producing leaves. In these cases
there is no true prolification, but simply an extension of the axis.
That the outer portion (so-called calyx-tube) of these fruits is really
an axile product there can now be little doubt; and, as if to show their
axile nature, they occasionally produce leaves from their sides, as
before mentioned. Moquin, in the tenth volume of the 'Bulletin of the
Botanical Society of France,' p. 73, says that when the case is one of
prolification the lower fruit is larger and is formed of a fleshy mass;
moreover, the line of demarcation between the fruits is more distinct,
and there are traces of the seed-bearing cavity in the interior, and of
calycine lobes at the top. On the other hand, if the case be one of
hypertrophy merely, the lowermost fruit is the smallest, and there is no
trace of seed-bearing cavity nor of sepals. See also under Hypertrophy.
Some other malformations usually referred to prolification of the fruit
seem due to branching of the inflorescence, as in _Plantago_, wheat,
maize; or to a simple extension of the axis beyond its ordinary limit,
as in some cones of firs, &c. It is obvious that the true fruits in
these cases are in no wise affected.
From these considerations it would appear better to abandon the use of
the expression prolification of the fruit, as unnecessary where it is
really applicable, and as delusive in the numerous other cases where it
is employed.
Median prolification of one or other kind has been met with in the
following genera:
_Leafy_. _Floral_.
Ranunculaceae. Clematis.
Anemone! *Anemone!
Ranunculus! *Ranunculus!
Delphinium.
Caltha.
Aquilegia!
Cruciferae. Bunias.
*Cheiranthus!
Erucago.
*Matthiola!
Sisymbrium!
Brassica!
Nasturtium.
Hesperis.
Sinapis!
Diplotaxis.
Lunaria.
Erysimum.
Alyssum.
Peltaria.
Cardamine!
Cleome.
Cistaceae. Helianthemum!
Caryophylleae. Dianthus! *Dianthus!
Silene!
Lychnis!
Violaceae. Viola!
Tiliaceae. Triumfetta!
Geraniaceae. Geranium!
Sapindaceae. Pavia! Pavia!
Malvaceae. Paritium.
Hibiscus!
Malpighiaceae. Byrsonima!
Rutaceae. Genera not specified. *Dictamnus!
Resedaceae. Reseda.
Caylussa!
Aurantiaceae. *Citrus!
Vitaceae. Vitis. Vitis.
Umbelliferae. Heracleum.
Angelica.
Thysselinum.
*Athamanta.
*Daucus!
*Torilis.
Rosaceae. *Rosa! *Rosa!
*Geum! *Geum!
Agrimonia. Amygdalus.
Prunus!
Spiraea! Spiraea!
Rubus.
*Pyrus! *Pyrus!
?Leguminosae Trifolium!
Medicago!
Melilotus.
Pisum!
Cucurbitaceae. Cucumis.
Passifloraceae. Passiflora.
Philadelphaceae. Philadelphus.
Onagraceae. Epilobium!
Epacridaceae. Epacris!
Ericaceae. *Erica.
Rhododendron!
Convolvulaceae. Convolvulus.
Gentianaceae. Gentiana. Gentiana.
Apocynaceae. Vinca.
Jasminaceae. Jasminum!
Scrophulariaceae. Verbascum! Antirrhinum!
*Digitalis!
*Linaria!
Veronica.
Orobanchaceae. Orobanche.
Labiatae. Genera not specified. Stachys.
Phlomis!
Hydrophyllaceae. Hydrophyllum.
Boraginaceae. Anchusa.
Symphytum.
Primulaceae. *Dodecatheon. *Cortusa.
*Anagallis! *Anagallis!
*Primula.
Dipsacaceae. Scabiosa.
Compositae. Hieracium! Hieracium!
Cirsium. Cirsium.
Hypochaeris. Calendula!
Spilanthes.
Carthamus.
Coreopsis.
Campanulaceae. Campanula. *Campanula!
Polygonaceae. Genera not specified. Rumex.
Santalaceae. Thesium.
Liliaceae. Genera not specified. Tulipa!
Hemerocallis!
Asphodelus.
Hyacinthus!
Iridaceae. Iris.
Amaryllidaceae. Narcissus!
Leucojum.
Orchidaceae. Orchis!
Habenaria.
Cyperaceae. Carex.
Gramineae. Phleum.
=Axillary prolification= is the term applied to those cases wherein one
or more adventitious buds spring from the axils of one or more of the
parts of the flower. Engelmann makes use of the word ecblastesis to
denote the same condition. Both terms are open to the objection that
they do not clearly enable us to distinguish prolification occurring
within the flower from a similar state originating outside the flower,
within the bracts of the inflorescence. This latter condition, called by
Moquin-Tandon lateral prolification (see Prolification of the
Inflorescence), is as truly axillary as that to which the name is
restricted. In consequence of certain peculiarities in the structure of
some flowers, to be hereafter alluded to, it is not in all cases easy to
decide whether the new growth springs from the interior of the flower,
or from the inflorescence beneath the flower.
The accessory bud presents itself as a leaf-bud, a branch, a flower-bud,
or a miniature inflorescence; it may be sessile, but is far more
frequently stalked, and in more than half the number of cases it is a
flower-bud or an inflorescence. There may be one or more of these buds;
if two only, then they are usually placed directly opposite one to the
other, on the opposite sides of the flower.
It will be seen, from the appended list, that the orders and genera in
which this description of adventitious growth occurs most frequently are
the following:--_Cruciferae_, especially the genus _Brassica_;
_Caryophyllaceae_, e.g. _Dianthus_; _Resedaceae_; _Leguminosae_, e.g.
_Melilotus_, _Trifolium_, &c.; _Rosaceae_, e.g. _Rosa_, _Potentilla_,
&c.; _Umbelliferae_, and _Campanulaceae_. For the most part, these are
groups also peculiarly liable to central prolification.
All the parts of the flower may be thus affected; but, as might have
been anticipated from the foliaceous nature of the sepals, the new bud
usually arises from within the axil of one of those organs. Next in
frequency to the calyx, the pistil is subjected to this change--the
carpels in such a case being disunited and leaf-like. The petals rank
next, and lastly the stamens; these latter, indeed, are usually, but not
invariably, absent, the new growth occupying their position. Hence it
may well be that when such is the case, there is no real axillary
prolification, but rather the substitution of a bud for a stamen.
Generally, however, the position of the accessory bud is such that it
may properly be referred to the axil of an undeveloped or rudimentary
stamen.
The largest number of instances of this malformation, not merely
generically, but also individually, occurs in plants the members of
whose floral whorls are not united one to the other; thus, it is far
more common in polypetalous plants than in gamopetalous ones. In the
prolified flowers belonging to the latter group, the sepals, if not
actually uncombined, are only united for a short distance. The same
relationship, but in a much less degree, exists in the case of median
prolification, as that aberration is likewise most commonly met with in
polypetalous flowers. Another feature of interest is the rarity with
which axillary prolification is found in irregular gamopetalous blooms.
It may be that the irregular and comparatively excessive growth in some
parts of these flowers, as compared with others, may operate in checking
any luxuriant tendency in other directions.
As in the case of median prolification, plants having an indefinite
inflorescence are more liable to be affected with ecblastesis than those
having a definite one. The degree of branching of the inflorescence may
be noticed, as this deformity is far more common in plants whose
peduncles are branched than in those which have either a solitary flower
or an unbranched flower-stalk. More than two thirds of the entire number
of genera cited as the subjects of this malformation have a branched
inflorescence of some form or other; and about two thirds of the cases
occur in genera having some form of indefinite inflorescence. If
individual instances could be accurately computed, the proportion would
be even higher.
Fully three fourths of the entire number of genera recorded as
occasionally the subjects of this irregularity possess in their usual
state some peculiarity of the thalamus; for instance, in about a third
of the whole number of genera the thalamus is more or less prolonged
between some or other of the floral whorl, e.g. _Caryophyllaceae_,
_Potentilla_, _Anemone_, _Dictamnus_, _Umbelliferae_, &c. About one
fourth of the genera have numerous stamens or numerous carpels, or both,
springing naturally from the thalamus. In others (about one sixth) the
thalamus is enlarged into a disc, or else presents one or more
glandular swellings, _e.g._ _Reseda_, _Nymphaea_, _Cruciferae_. In the
last-named family, as has been already remarked, prolification is very
common. It would be interesting to ascertain precisely what part of an
inflorescence is most liable to this affection; but as information on
this point is but rarely given in the records of these cases, I can only
give the results of my own observations, which go to show that, in a
many-flowered inflorescence, those flowers at the outside, or at the
lower portion, seem to be more frequently the subjects of this change
than those situated elsewhere. This may probably be accounted for by the
fact that the malformation is met with most generally in plants with an
indefinite form of inflorescence, and therefore the lowermost or
outermost flowers are most fully nourished; the upper flowers being in a
less advanced condition, the change is more likely to be overlooked in
them; or it may be that from the unusual luxuriance in the lower
flowers, the upper ones may be either present in their ordinary
condition, or may be (as indeed frequently happens) stunted in the size
and proportion of their several parts.
=Axillary foliar prolification of the flower.=--The formation of an
adventitious leaf-bud in the axil of any of the parts of the flower is
not of such common occurrence as the development of a flower-bud in
similar situations, nor is it so frequent as median foliar
prolification. I have seen leafy shoots proceeding from the axils of the
sepals in the flowers of _Brassica_, and a similar occurrence has been
noticed in _Caltha palustris_, _Herreria parviflora_, and other plants.
Dr. Marchand's flowers of _Anagallis_, previously referred to at p. 117,
showed good illustrations of this occurrence, as also some specimens
described by Kirschleger in _A. phoenicea_.[134] Steinheil has figured
and described[135] a flower of _Scabiosa_ in which there was an
adventitious formation of leafy shoots in the axil of the outer calyx.
In some flowers, such as _Convolvulus_, _Anemone_, &c., the exact nature
of the sub-floral leaves is uncertain, _i.e._ it is open to doubt
whether the organs in question are bracts or leaves pertaining to the
inflorescence, or whether they are really parts of the flower. When
leafy shoots are formed in the axils of such organs, the adventitious
growth may be referred to extra-floral prolification, prolification of
the inflorescence that is, or to axillary prolification, according to
the view taken of the real nature of the sub-floral leaves. So far as
the mere occurrence of prolification is concerned, it is not very
material which view be adopted. The same remark applies to cases where
leaf-buds occur on the outer surface of inferior ovaries, as in
_Rosaceae_, _Pomaceae_, _Philadelphus_, or _Tetragonia expansa_, as
elsewhere mentioned.
It would seem more consistent with the general arrangements of parts,
that the adventitious buds should be formed more frequently outside than
within the flower proper.
Knight[136] figures and describes the occurrence of small tubers or
fleshy leaf-buds in the axils of the sepals of a potato, a curious
illustration of the real morphological nature of the tuber.
=Axillary floral prolification of the flower.=--As already stated, this
is of more common occurrence than the formation of a leaf-bud in a
similar situation. Any of the parts of the flower may thus subtend a
flower-bud, though probably the new buds more frequently originate in
the axils of the sepals than in the other whorls. In _Cruciferae_ the
change in question is, relatively speaking, very common. In cauliflowers
and broccoli I have frequently met with stalked flowers proceeding from
the axils of the sepals, so also in some fuchsias I have seen a ring of
stalked flower-buds alternating with the petals, which, together with
the stamens and pistil, remained unaffected. The number of parts in the
supernumerary structures is generally less than the normal flowers.
In Mr. Herbert Spencer's 'Principles of Biology,' part iv, p. 37, are
figured and described some monstrous inflorescences in _Angelica_ and
other _Umbelliferae_, from which, amongst other things, the author draws
the conclusion that there is no absolute distinction between leaf and
branch. Without staying for the moment to discuss this matter, it may
here be said that the Umbellifers in question apparently owe their
peculiarities rather to axillary prolification within the flower, or to
prolification of the inflorescence, than to an actual transformation of
a flower or any portion of a flower into an umbellule.[137]
In the 'Gardeners' Chronicle,' 1855, p. 551, an instance is figured of
the production of a supernumerary flower proceeding from the axil of a
stamen in a species of _Nymphaea_ (fig. 65). The ovary in this case was
wanting, but in its place was a tuft of small leaves. It is curious that
among Dr. Kirk's drawings of east tropical African plants now at Kew,
there should be one representing a precisely similar state of things.
The species in both instances was _Nymphaea Lotus_, or a cultivated
variety of it.
M. Wesmael[138] describes a very singular case of what appears to have
been referable to axillary prolification in the flowers of _Carex
acuta_. The rachillus is described as prolonged through the utricle by
the side of the stigmas, bearing on its side a bract, then a secondary
utricle, from the axil of which sprung a short stem surmounted by an
ovary. Wigand, 'Flora,' 1856, mentions a similar change in _Carex
glauca_. In this instance the base of the female inflorescence bore
lateral spikes, which projected from the utricles; some of these
adventitious spikes were female, others female below and male above,
others, again, wholly male.
[Illustration: FIG. 65.--Flower of _Nymphaea Lotus_, var., showing
axillary floral prolification. The section also shows the tuft of leaves
that occupied the place of the ovary.]
Various changes in the form and arrangement of the several floral whorls
accompany axillary prolification; some of these affect the particular
organ or organs implicated, and these only, while in other cases some
other parts of the flower likewise undergo modification. The changes
most commonly met with are such as may be classed under Goethe's theory
of retrograde metamorphosis; for instance, if a supplementary bud be
developed in the axil of a sepal, that sepal is likely to be more than
ordinarily leaf-like in appearance. The dislocation of the affected
sepal from its fellows is a very frequent occurrence; in cases of this
kind the detached sepal is placed below the others, thus approximating,
in position as well as in function, to the bracts. In some of the
instances of proliferous pears, on which I shall have occasion to
comment, the sepals are described as sharing in the succulent character
of the fruit.
The petals, under such circumstances, often exist in the guise of sepals
or of small leaves; and instances are recorded wherein the place of the
calyx and corolla was supplied by a succession of overlapping green
scales, from the axils of which the new buds arose. M. Germain de Saint
Pierre records such a case in _Trifolium repens_, wherein the calyx and
corolla were replaced by overlapping scales, in the axils of each one of
which arose a flower; above there was a row of stamens, and in the
centre a pistil in the guise of a trifoliate leaf.[139] Such instances
seem to afford an extreme degree of a more common change, viz., the
diminished size and contracted appearance of the sepals and petals when
affected with axillary prolification. They have also a close
relationship to such developments as we see in the wheat-ear carnation,
in certain species of the genus _Maesa_ and others, wherein the calyx is
repeated over and again, to the partial or complete suppression of the
other parts of the flower. All these cases may be in part explained by
the operation of the principle of compensation.
So far as the androecium is concerned, the stamens either remain
unaltered, or they are present in a more or less petal-like condition;
but it far more frequently happens that the stamens are entirely
suppressed, the adventitious bud supplying their place; thus was it in
the _Dianthus_ represented in the adjoining woodcut, fig. 66, where the
stamens were entirely absent, and their places supplied by
flower-bearing branches. This _Dianthus_ has the more interest from its
similarity to the one described by Goethe, Metam. der Pflanzen, cap.
16, sect. 105; but in that instance median prolification also existed.
For my specimens I am indebted to Mr. T. Moore.
[Illustration: FIG. 66.--Flower of _Dianthus_ sp., calyx removed; petals
turned down so as to show the stalked flower-buds springing from their
axils.]
The pistil, too, is necessarily subject to very grave alterations when
affected with this malformation. It is separated into its constituent
carpels; and these assume a leaf-like aspect, and are in the great
majority of instances destitute of ovules. Indeed, virescence or
chloranthy is very intimately connected with this aberration, as might
have been anticipated, for if the parts of the flower assume more or
less of the condition of stem-leaves or bracts, it is quite natural to
expect that they will partake likewise of the attributes of leaves, even
at the expense of their own peculiar functions.
It occasionally happens that an adventitious bud arises from the axil of
a monocarpellary pistil. This takes place sometimes in _Leguminosae_, and
seems to have been more frequently met with in _Trifolium repens_ than
in other plants. The species named is, as is well known, particularly
subject to a reversion of the outer whorls of the flower to leaves, and
even to a leaf-like condition of the pistil. There are on record
instances wherein a leaf-bud has been placed in the axil of a more or
less leaf-like carpel; while at other times a second imperfect carpel
has been met with in the axil of the first.[140] I have myself seen
numerous imperfectly developed cases of this kind.
It may be asked whether such cases are not more properly referable to
central prolification--whether the axis is not in such flowers
terminated by two, rather than by one carpel? It is, however, generally
admitted by morphologists that the solitary carpel of _Leguminosae_ is
not terminal, but is the sole existing member of a whorl of carpels, all
the other members of which are suppressed as a general rule, though
exceptional instances of the presence of two and even of five carpels
have been described.[141]
Again, the adventitious bud or carpel is placed, not laterally to the
primary one, or opposite to it, on the same level, but slightly higher
up--in fact, in the axil of the primary carpellary leaf. Griffith
figures and describes[142] an instance of the kind in a species of
_Melilotus_. The stalk of the ovary is mentioned as having a sheathing
base, bearing in its axil a prolongation of the axis of inflorescence,
in the form of a short spike with hairy bracts and imperfect flowers,
the latter having a well-formed calyx and rudimentary petals and
stamens. Griffith infers, from this specimen, that the legume is not to
be considered as a terminal leaf.
_List of Genera in which Axillary Prolification has been observed._
Order Genus. Leaf-bud Flower-bud or From what organ.
or Branch Inflorescence
Ranunculaceae Clematis Flower-bud Sepals.
Caltha Ditto Ditto.
Aconitum Ditto.
Delphinium Ditto Sepals, carpels,
&c.
Anemone! Ditto Involucre?
Nymphaeaceae Nymphaea! Fruit?
Nymphaea Flower Petal.
Cruciferae *Brassica! Leaf-bud Flower-bud Sepals and
petals.
Brassica! Ditto Stamens.
Brassica! Ditto Ditto Pistil.
Cardamine! Ditto Sepals.
Matthiola! Ditto Sepals and
petals.
Cheiranthus! Ditto Sepals.
Erysimum Ditto Sepals and
pistils.
Lepidium! Ditto Petals and
stamens.
Arabis Ditto Sepals.
Diplotaxis Flower, Pistil, calyx
inflorescence and corolla.
Capsella
Capparidaceae Cleome Flower-bud Sepals.
Resedaceae *Reseda Ditto Ditto.
Caryophyllaceae Arenaria Branch Ditto.
Agrostemma Leaf-bud Ditto.
*Lychnis Ditto
Stellaria Ditto
Silene Ditto
*Gypsophila Ditto Ditto Sepals and
stamens.
*Dianthus! Ditto Ditto Sepals.
Dianthus! Ditto Inflorescence Petals and
stamens.
Cucubalus Sepals
Saponaria! Sepals and
petals.
Malvaceae Alcea Flower-bud Stamen.
Aurantiaceae Citrus! Ditto Ditto.
Rutaceae Dictamnus! Ditto Pistil leafy.
Tropaeolaceae Tropaeolum! Ditto Petals.
Celastraceae Celastrus Ditto Sepals.
Leguminosae *Melilotus! Inflorescence Sepals and
petals.
Medicago Flower-bud Sepals.
Coronilla Ditto Ditto.
Trifolium! Ditto Second carpel Pistil.
axillary to
first
Melilotus! Ditto Ditto
Trifolium! Flower-bud Sepals and
petals.
Rosaceae Pyrus! Fruit? Fruit?
Cerasus! Flower-bud Petals and
stamens.
Potentilla! Ditto Leafy carpels.
Crataegus! Ditto Petals.
*Rosa! Ditto Ditto Sepals, petals,
stamens and
pistil.
Myrtaceae Lecythis Ditto Fruit?
Tetragoniaceae Tetragonia? Ditto Ditto.
Cactaceae Opuntia! Fruit-like Tufts of spines.
branch
Pereskia Ditto Sepals?
Echinocactus Ditto Ditto.
Philadelphaceae Philadelphus Ditto Sepals.
Umbelliferae *Athamanta Ditto Calyx.
*Daucus! Ditto Calyx and
pistil.
Bupleurum Ditto Calyx and
pistil.
Torilis Ditto Calyx and
pistil.
Apium Flower-bud Calyx and
pistil.
Pastinaca Ditto Ditto ditto.
Heracleum! Ditto Ditto ditto.
Angelica! Umbel Ditto ditto.
Campanulaceae *Campanula! Branch Sepals.
Prismatocarpus Ditto Fruit Sepals, &c.
Gentianaceae Gentiana! Flower-bud Sepals.
Convolvulaceae *Convolvulus! Ditto Outer calyx.
Solanaceae Solanum! Ditto Sepals.
Solanum Tubers Sepals and
petals.
Scrophulariaceae *Digitalis! Ditto Petals, &c.
Veronica Raceme Calyx.
Primulaceae Anagallis! Branch Ditto Petals.
Primula Ditto Petals and
carpels.
Polygonaceae Rumex Ditto Sepals.
Santalaceae Thesium Leaf-bud In place of
stamens and
pistils, both
absent.
Euphorbiaceae? Euphorbia? Ditto Outer bracts?
Orchidaceae Orchis! Flower-bud Perianth.
Amaryllidaceae Leucoium Ditto Ditto.
Iridaceae Iris Ditto Pistil.
Liliaceae Herreria Ditto Sepals.
Hyacinthus Flower and Perianth.
raceme
Convallaria Flower-bud Ditto.
Allium Ditto Ditto.
Cyperaceae Carex Inflorescence Utricle.
[Illustration: FIG. 67.--Proliferous Rose. Calyx leafy; petals normal,
some reflexed; stamens and pistil absent; in their places a branch with
leaves and flowers.]
[Illustration: FIG. 68.--Rose exhibiting median, axillary, lateral,
floral, and leafy prolification in same flower.]
=Complicated prolification.=--From what has been before stated it may be
seen that prolification of two or more kinds may coexist in the same
flower. Mixed leafy and floral prolification is not unfrequent in
proliferous roses, where a shoot is, as it were, prolonged through the
centre of the original flower and terminated by a second flower, or
even by a cluster, as is well shown in the accompanying figure (fig.
67). Median and axillary prolification, also, not unfrequently coexist
in the same flower; thus, in a proliferous rose forwarded to me by Mr.
W. Thomson (fig. 68), the following changes were observed:--the swollen
portion below the calyx, the "hip," was entirely absent; the sepals were
leaf-like in aspect, the petals unaffected; above the petals the axis
was prolonged for a short distance and then bore a circlet of miniature,
sessile roses, destitute, indeed, of calyx, but provided with numerous
petals, stamens, and pistils. Above these lateral flowers, the prolonged
axis bore a number of scales in many rows. The scales were in their turn
surmounted by a whorl of five perfect leaves, beyond which, again, the
axis was prolonged into a leafy shoot terminated by a flower bud, the
whole constituting a remarkably complicated admixture of elements
belonging to the flower, the bud, the inflorescence, and the
leafshoot.[143]
Proliferous flowers of Orchids also occasionally present great
complexity in the arrangement of their parts. An instance of this kind
was described by myself from specimens furnished by Dr. Moore, of
Glasnevin, in the 'Journal of the Linnean Society,' vol. ix, p. 349,
tabs. x, xi, and from which the following summary is extracted:
[Illustration: FIG. 69.--Proliferous Orchis. Diagram showing the
arrangement of the several organs in the seven outer circles of the
flower. Each whorl is numbered, and the position of the axillary buds
shown by the small circles.]
The primary flowers were composed of five distinct whorls, and of at
least two others less perfectly developed. These primary flowers did not
give rise to median formations, but they produced secondary buds in the
axils of the segments of the perianth. These latter buds were themselves
the subject of tertiary prolification of both kinds, median and
axillary. The tertiary median growths, like the primary flower, did not
develop median buds, but only lateral ones--quaternary axillary
prolification.
The accompanying diagrams are intended to show the plan of arrangement
in these flowers. Fig. 69 shows the disposition of parts in the primary
flower and the situation of the axillary buds. Fig. 70 shows the primary
flower without any central prolongation, but giving off axillary buds,
two of which are shown in the diagram, 2, 2; these are, each of them,
the subject of both median, 3, 3, and axillary prolification, 4', 4'.
[Illustration: FIG. 70.--Diagram to explain the construction of the
double-flowered _Orchis_.
1. The primary flower, with no median bud, the position of which, had it
been present, is shown by the dotted line.
2. Two axillary buds proceeding from 1, and themselves giving origin to
3, 3. Median buds, and 3', 3', axillary buds.
4' 4'. Axillary buds, proceeding from 3. No median bud is produced from
3; its situation, had it been present, is indicated by the dotted line.]
In _Narcissus major_ a similar combination of both forms of
prolification exists, as described by Morren.[144]
On the general subject of Prolification in flowers, in addition to the
authorities already cited, the reader may refer to the following among
many others:
Linnaeus, 'Prolepsis,' Secs. vi et vii. Goethe, 'Versuch.
Metamorph.,' cap. xv and xvi Secs. 103-106. Moquin-Tandon,' El.
Ter. Veg.,' p. 362, &c. Engelmann, 'De Antholys.,' Secs. 52-62,
&c. Cramer, 'Bildungsabweichungen,' &c. _Orchidaceae_,
_Umbelliferae_, _Compositae_, _Leguminosae_, _Primulaceae_,
_Ranunculaceae_. Fleischer, 'Missbild. Cultur Gewachs.'
Schlechtendal, 'Linnaea,' xv, p. 408, _Rosa_. 'Bot. Zeit.' vol.
xx, 1862, p. 382, _Cyclamen_. 'Bot. Zeit.,' vol. xx, p. 301,
_Asphodelus_; et _Lilium_. Seringe, 'Bull. Bot.,' i, t. xi, f.
7, 8, _Arabis_, _Diplotaxis_. Clos, 'Mem. Acad. Toulouse,' 5th
ser., 1862, _Papaver_. Wigand, 'Flora,' 1856, p. 716,
_Hypochaeris_; et 'Bot. Untersuch.,' p. 19. Buchenau,'
Flora,' 1857, p. 295, _Reseda_. Roeper, 'Bot. Zeit.,' 1852, p.
427, _Orchis_. Presl., 'Linnaea,' vi, p. 599, tab. ix, figs.
5-8, _Sisymbrium_, Vrolik., 'Flora,' 1846, p. 97, t. i et ii,
id. 1844, t. i, _Digitalis_. See also Schlechtendal, 'Bot.
Zeit.,' vol. ix, 1851, p. 579. Klinsmann, 'Linnaea,' x, p. 604,
t. v, _Hesperis_. Fuckel, 'Flora,' 1848, p. 609. _Melilotus_.
De Candolle, 'Organogr.,' i, 396, t. 33. Turpin, 'Atlas de
Goethe,' p. 65, t. 5, figs. 12, 13. Fenzl. 'Sitzungsbericht d.
k. Akad. d. Wissensch. Wien.,' heft, iii, tabs. 3, 4, _Rosa_.
Kirschleger, 'Flora,' 1845, 613, _Dianthus_, _Rosa_.
'Institut.,' 1841, No. 413, p. 421, _Tragopogon_. Baron de
Melicoq., 'Ann. Sc. Nat.,' 3rd ser., vol. v. 1846, p. 61,
_Antirrhinum_. Reichenbach, 'Icon. Fl. Germ.,' tab. 100,
_Reseda_--"monstrosa anticipatio Euphorbiacearum et
Capparidearum." Duhamel, 'Phys. Arbres.,' liv. iii, cap. 3, p.
303, pl. xii, f. 306, _Rosa_. Caspary, 'Bull. Soc. Bot. Fr.,'
vol. vi, 1859, p. 235, Rev. Bibl., _Pyrus_. Eichler, 'Flora,'
1865, tab. ix, _Cleome_. Lindley, 'Elements of Botany,' p. 63,
&c., _Rosa_, _Epacris_, _Anagallis_, _Pyrus_. Irmish, 'Flora,'
1858, p. 38, _Pyrus_; and 'Bot. Zeit.,' xix, 1861, p. 342,
_Hyacinthus_. Duchartre, 'Bull. Soc. Bot. France,' 1861, p.
451, _Rosa_. Weber, 'Verhandl. Nat. Hist. Verein. Rhein.
Preuss., &c.' 1858 et 1860. Landrin, 'Mem. Soc. Sc. Nat. Seine
et Oise,' 1866?[145] Masters, 'Trans. Linn. Soc.,' vol. xxiii,
p. 359, tab. 34 and p. 481, tab. 54.
=Prolification of the embryo.=--This term was applied by Moquin-Tandon
to a peculiar condition of the almond (_Amygdalus_), in which, indeed,
it is not of unfrequent occurrence. In these cases one almond encloses
within its cotyledons a second embryo, and this, again, in some
instances, a third, the little plants being thus packed like so many
boxes one within the other. The supplementary embryos are, in the ripe
state at least, quite separate and detached one from another. These
cases differ from the ordinary instances wherein there is an increased
number of embryos in one seed in their position. In the latter case, as
often happens in the seeds of the orange, the new products are placed by
the side one of another.[146]
For other cases of prolification or the adventitious formation of buds
on leaves, roots, &c., see under Heterotaxy.
FOOTNOTES:
[104] Linn., 'Prolepsis,' Sec. vii; Goethe, 'Metamorph.,' Secs. 96,
103, 106.
[105] "Diaphysis inflorescentiarum." Engelmann, 'De Anthol.,' Sec. 85.
[106] 'Flora,' 1844, p. 565.
[107] 'Ann. Sc. Nat.,' ser. 3, vol. v, 1846, p. 64.
[108] 'Bot Zeit.,' vol. xx, p. 382.
[109] 'Miscel. Austriac. Bot.,' vol. i, Vindob, 1778, p. 133.
[110] "_Umbellati dum prolificantur, augent umbellulam, ut ex umbellula
simplici altera exeat_." 'Linn. Phil. Bot.,' Sec. 124.
[111] 'En. Euphorb.,' p. 36.
[112] Meisner. 'Mon. Gen. _Polygoni_ Prodrom.,' p. 20, tab. v, considers
the bulbils of this plant to be modifications of the pedicels of the
flower.
[113] See A. Braun. 'Ann. Scienc. Nat.,' 4th series, 1860, vol. xiv, p.
13.
[114] "_Prolificatio e latere ex calyci communi proles plurimos
pedunculatos emittens, fit in compositis aggregatis proprie dictis._"
'Linn. Phil. Bot.,' Sec. 124.
[115] 'Bot. Zeit.,' 1857, p. 873. See also 'Verhandl. Nat. Hist.
Vereins. Preuss. Rheinl. u. Westphal.,' 1854, t. ix.
[116] "Pannicula spicatim sparsa onusta innumera foetura herbaceorum
flosculorum racematim cohaerentium," 'Lobel. Stirp. Hist.,' p. 163. This
is the "Besome Plantain, or Plantain with spoky tufts," of Ray,
'Synopsis,' p. 314. Gerard's 'Herbal,' Ed. Johnson, p. 420. Parkinson,
'Theat. Bot.,' p. 494. Baxter, 'Loudon. Mag. Nat. Hist.,' vol. ix. p.
204, and vol. iii, p. 482. fig. 118.
[117] 'Flora.' 1856. p. 706.
[118] 'Flora of Berwick-on-Tweed,' vol. i. p. 38.
[119] 'Adansonia,' vol. iv. 1864, p. 150, tab. vii. 'Gard. Chron.,'
November 19th, 1864.
[120] 'Ann. Sc. Nat.,' ser. 3, tom. ii, p. 290; and 'Adansonia,' iii,
tab. iv; see also Bureau, in 'Bull. Soc. Bot. France,' x, p. 191.
[121] Baillon, 'Adansonia,' i, 286.
[122] See also figure in 'Hort. Eystett. Ic. Plant. Vern.,' fol. 15,
fig. 1. _Ranunculus asiaticus_.
[123] Duchartre, 'Ann. des sc. nat.,' 3me serie, vol. ii, 1844, p. 293.
[124] Reissek, 'Linnaea,' vol. xvii, 1843, p. 641, tab. xix.
[125] The tube of the calyx in these specimens was traversed by ten
ribs, apparently corresponding to the primary ridges of the normal
fruit; these ribs were destitute of spines, and the bristly secondary
ridges were entirely absent. Those portions of the carpels which were
detached from the calyx had each three ribs, a central and two lateral
ones, which appeared to be continuous with the ribs of the calyx
below,--although in the case of the calyx there were ten, in the case of
the carpels six ribs, three to each. This diversity in number is thus
explained:--A circle of vascular tissue ran round the interior of the
calyx-tube, at its junction with the limb, and at the point of insertion
of the petals and stamens. The vascular circle seemed to be formed from
the confluence of the ten ribs from below. Of the five ribs in each half
of the calyx, the three central ones were joined together just at the
point of confluence with the vascular circle, above which they formed
but a single rib--that traversing the centre of the carpellary leaf; the
two lateral ribs of each half of the calyx seemed to be continuous,
above the vascular rim, with the lateral ribs of the carpel; these
lateral ribs were connected on either side with the central one by short
branches of communication. The disposition of the ten ribs may be thus
represented:--
1 1 1 1 1 1
3 2 3 2 3 3 2 3 2 3
1 1 1 1 1 1 1 1 1 1
The lower line of figures represents the calycine ribs, the middle row
shows how each of these ribs is divided at the vascular rim, and the
uppermost row shows their distribution above the rim. From this it will
be seen that six of the calycine ribs divide into three branches, one
prolonged upwards as a lateral or median rib into the carpellary leaf,
the other running horizontally to join with similar branches sent out
from the neighbouring rib; the four intermediate calycine ribs divide
into two branches only, which join the side branches of the first
mentioned, but have no direct upward prolongation into the carpel. The
ten ridges are placed opposite to the sepals and petals.
[126] 'Neue Denkschriften der allgemeine Schweizerischen Gesellschaft,'
band 5. 1841. tab. 2.
[127] Bell Salter, 'Gard. Chron.,' March 13th, 1847, and 'Ann. Nat.
Hist.,' 1847, vol. xix, p. 471. &c.
[128] 'The Origin and Production of Proliferous Flowers, with the
Culture at large for raising Double Flowers from Single, and Proliferous
from the Double.' By J. Hill, M.D. London, 1759.
[129] A. de Candolle, 'Neue Denkschriften,' op. cit., p. 9; also Unger
as cited in 'Botanical Gazette,' May, 1351. p. 70.
[130] Duchartre, op. cit.
[131] 'Ann. Sc. Nat.,' 1844, vol. i, p. 297.
[132] Maout, 'Lecons Elementaires de Botanique,' vol. ii. p. 488;
Ferrari. 'Hesperides.' pls. 271, 315, 405.
[133] Moquin-Tandon, loc. cit., p. 386, &c.; see also Trecul, in the
'Bull. Soc. Bot. France,' tom. i, p, 307.
[134] 'Bull. Soc. Bot. Fr.,' 1863, vol. x, p. 461.
[135] 'Ann. Sc. Nat.,' 1835, p. 65. See also Le Maout, 'Lecons
Element.,' vol. ii, p. 426.
[136] 'Proc. Hort. Soc.,' vol. i, p. 39, fig. 2.
[137] See also 'Nat. Hist. Review,' 1865, p. 377.
[138] 'Acad. Roy. Belg.,' April 11th. 1863.
[139] 'Bull. Soc. Bot. Fr.,' tom. iii, 1856, p. 479.
[140] 'Linnaea,' vol. xv, p. 266, _c. ic._ Caspary, 'Schriften d.
Physik.-Oek. Gesell. zu Koenigsberg,' bd. ii, p. 5, tab. iii, fig. 39,
&c.
[141] Lindley, 'Veg. King.,' p. 545; also Clarke on the Position of
Carpels, Linn. Soc.,' December, 1850. 'Proc. Linn. Soc.,' ii, p. 105.
[142] 'Notulae,' vol. i, Dicot. p. 127. 'Atlas,' pl. xliii.
[143] Moquin-Tandon gives the following references to cases of
proliferous roses, but some I have not been able to verify. 'Journ. des
Sav.,' 22 Mai 1679. Hottinger, 'Ephem. Nat. Cur.,' dec. 3 ann. 9 et 10,
p. 249. Marchant, 'Mem. Acad. Scienc. Paris.' 1707, p. 488. Preussius,
'Ephem. Nat. Cur.,' cent. 7 et 8. App. p. 83. Schuster, 'Act. Acad. Nat.
Cur.,' vol. vi, p. 185. Spadoni, 'Mem. Soc. Ital.,' t. v, p. 488. See
also at the end of this section for numerous other references.
[144] 'Bull. Acad. Belg.,' t. xx, part ii, p. 271. See also Bellynck,
'Bull. Soc. Bot. Belg.,' t. vi, ex. 'Bull. Soc. Bot. France,' t. xiv,
1867, Rev. Bibl., p. 241. _Orchis ustulata_.
[145] I have not been able to meet with this, but it is said to contain
a paper on prolification, with numerous bibliographical references.
[146] 'El. Ter. Veg.,' p. 364, Adnot.