The flowers are _hypogynous_ and _zygomorphic_ (in _Boraginaceæ_ and
_Cordiaceæ_, however, they are regular, except _Echium_ and _Anchusa
arvensis_). The calyx is gamosepalous, the corolla _bilabiate_ (except
in the two orders mentioned), mostly after 2/3, _i.e._ divided into
a 2-leaved posterior portion, and a 3-leaved anterior portion.
The æstivation of the corolla is nearly always descending.--In
_Boraginaceæ_ and _Cordiaceæ_ there are 5 stamens of equal length; in
the other orders 4 didynamous ones, or only 2 fertile; the posterior
stamen is sometimes developed as a staminode, sometimes fertile (in
_Stilbaceæ_). The ovary is formed of 2 median carpels (except some
_Verbenaceæ_), with (1-) =2= ovules on each carpel; in the majority of
the orders it is, however, divided by a false partition-wall between
the dorsal and ventral sutures, into =4= _loculi_, each of which is
often raised independently, causing the style to be situated in the
depression between the four lobes (“gynobasic” style, Figs. 572,
573, 575, 579). The fruit in these orders most frequently becomes a
_4-partite schizocarp_ with _nut-like fruitlets_. The other orders have
a 1(-2)-locular ovary.--The leaves are _simple, without stipules_.
The family is related to (and proceeds from) the _Tubifloræ_,
especially _Convolvulaceæ_, which has an almost similar
construction of the ovary. It is doubtful whether the
_Cordiaceæ_ and _Boraginaceæ_ should be classed with the others.
The orders are: 1, Cordiaceæ; 2. Boraginaceæ; 3, Verbenaceæ; 4,
Labiatæ; 5, Selaginaceæ; 6. Globulariaceæ; 7, Stilbaceæ.
Order 1. =Cordiaceæ= unites Convolvulaceæ and Boraginaceæ.
Tree-like plants with 5-(4–10) merous flowers, doubly bifid
style, and drupe with 4 or less loculi. No endosperm; cotyledons
folded.--185 species; tropical.
Order 2. =Boraginaceæ.= The vegetative parts are very characteristic:
_herbs_ with _cylindrical_ stems and _scattered_, undivided, nearly
always sessile, entire leaves, without stipules, and generally,
together with the other green portions of the plant, covered with
stiff hairs, consequently rough and often even stinging (hence
the other name for the order _Asperifoliæ_). The inflorescences
are _unipared scorpioid cymes_ with the branches coiled spirally
(“helicoid,” Fig. 573) before the flowers open. The flower is perfect,
_regular_ (obliquely zygomorphic in _Echium_ and _Anchusa arvensis_),
hypogynous, gamopetalous: S5, P5 (often with ligular outgrowths),
A5, G2, but each of the two loculi of the ovary becomes divided by a
false partition-wall into two, each of which contains one _pendulous_
anatropous ovule with the micropyle turned upwards; the four loculi
arch upwards, so that the ovary becomes 4-lobed, and the style is
then, as in the _Borageæ_, placed _at the base_ (“gynobasic”) between
the four projections (Figs. 572, 573). The fruit is a _4-partite
schizocarp_ with four nut-like fruitlets (Fig. 572).--_Endosperm is
wanting_ (except in _Heliotropium_); the radicle is turned _upwards_.
The INFLORESCENCES are often double unipared scorpioid cymes;
the bud of the second bracteole is developed, that of the first
suppressed; in some cases both the bracteoles are suppressed
(_Myosotis_, _Omphalodes_, etc.), but in other instances all
the first bracteoles (_a_) only are suppressed, and the others
are then situated in two rows towards the under side of the
coiled axis, while the flowers are situated on the upper side.
Displacement of the branches or of the floral-leaves sometimes
takes place. The flowers are often red at first, and later on
become blue or violet; they hardly ever have any smell. The
fruit entirely resembles that of the Labiatæ, but the radicle
of the latter is turned downwards. The fruitlets present small
differences which have systematic importance; they are hollow or
flat at the base, attached to a flat or columnar receptacle, etc.
=1.= HELIOTROPIEÆ. This group deviates from the characteristics
mentioned above in the undivided ovary and terminal (“apical”) style.
In this, as well as in the fact that in some genera (_Tournefortia_,
_Ehretia_, etc.) the fruit is a drupe, it connects this order with the
Cordiaceæ. _Heliotropium_, _Tiaridium_, and others have schizocarps.
=2.= BORAGEÆ, BORAGE GROUP. Style gynobasic; fruit a schizocarp.
=A.= The throat of the corolla is without ligules, or with very small
ones.--_Pulmonaria_ (Lung-wort); funnel-shaped corolla; a whorl
of hairs in the corolla-throat.--_Echium_ (Viper’s-bugloss) has
zygomorphic flowers, the plane of symmetry almost coinciding with that
of the very well-developed inflorescence (through the fourth sepal);
the corolla is obliquely funnel-shaped, the style is more deeply cleft
at the apex than in the others; stamens 2 longer, 2 shorter, and 1
still shorter.--_Cerinthe_ has a tubular corolla with five small
teeth and two bilocular fruitlets. The bracts are large and leafy,
and, like all the rest of the plant, are _almost glabrous_.--A few
_Lithospermum_-species have a naked corolla-throat; others have small
hairy ligules, which do not close the corolla-throat. The fruitlets
are as hard as stone, owing to the presence of carbonate of lime and
silica.--_Mertensia_ (_Steenhammera_); _Arnebia_; _Nonnea_ (small
ligules).
=B.= The corolla-throat is closed by, or in any case provided with
_ligules_, _i.e._ scale-like bodies or small protuberances, situated
in the throat of the corolla _opposite_ the petals, and which are
invaginations or _internal_ spurs of the petals (Fig. 572 _D_).--The
nuts in _Cynoglossum_ (Hound’s-tongue) bear _hooked bristles_ over the
entire surface, or, in _Echinospermum_, only on the edge. The following
have smooth nuts:--_Symphytum_ (Comfrey) has a cylindrical, campanulate
corolla, and prolonged-triangular, pointed ligules.--_Borago_
(Borage) has a rotate corolla with projecting, emarginate ligules;
the stamens have a horn-like appendage, projecting upwards from the
back of the filament. The fruitlets are hollow below.--_Anchusa_
(Alkanet, Fig. 572). The corolla is salver-shaped; the ligules
small, hairy protuberances. _A. (Lycopsis) arvensis_ has an S-curved
corolla-tube.--_Myosotis_ (Forget-me-not, Fig. 573); rotate corolla
with small (yellow) protuberances in the throat; scorpioid cyme without
floral-leaves; fruitlets flat.--_Omphalodes_; fruitlets hollow at the
back, with a scarious, turned-in, toothed edge.--_Asperugo_ (Mad-wort);
the calyx grows after flowering, becoming large, compressed, and
deeply bifid.
[Illustration: FIG. 572.--_Anchusa officinalis_: _A_ diagram;
the brocteole _a_ is suppressed (dotted); β supports a flower.
_B_, _C_ _Myosotis_, the fruit, entire and with the calyx in
longitudinal section. _D_, _F_ _Alkanna tinctoria_: D the corolla
opened (4/1); _e_ the ligule; _f_, _g_ the anthers; _E_ gyncœceum
(3/1); _F_ fruit, with three fruitlets; _i_ an aborted loculus;
_h_ disc.]
CROSS-POLLINATION is most commonly effected by insects
(especially bees). There are a great many contrivances for
pollination; some flowers are protandrous (_Echium vulgare_,
_Borago officin._), others are heterostylous (long-and
short-styled: _Pulmonaria officin._); the corona (ligules) is
a protection against rain, and excludes certain insects. Some
are barren when self-pollinated (_Pulmonaria officinalis_,
_Echium vulgare_); others which have but little honey, may,
failing insect-pollination, fertilise themselves, and in
_Myosotis versicolor_ this regularly occurs by the growth of the
corolla during flowering, so that the anthers are brought into
contact with the stigma. Honey is secreted on the hypogynous
disc.--About 1,150 species, growing especially in the northern
temperate zone, _Mucilage_ is found (_e.g._ in the _officinal_
root of _Cynoglossum officinale_, in the root of _Symphytum_):
red _dyes_ are found in some roots (_e.g._ Alkanet-root, the
root of _Alkanna tinctoria_, which is also medicinal; S. E.
Europe, Asia Minor); some are _poisonous_: _Cynoglossum_,
_Echium_, _Anchusa_, etc. Several species are ornamental plants.
_Heliotropium_ (Peru) is cultivated chiefly on account of its
pleasant scent; essential oils are otherwise very rare.
[Illustration: FIG. 573.-_Myosotis._ Inflorescence and gynœceum.]
Order 3. =Verbenaceæ.= The majority are shrubs; a few are herbs or
trees (Teak-tree); some are lianes. The branches are often square.
The leaves are opposite or verticillate, without stipules; in some
compound. The inflorescences are racemes, spikes, capitula, or
dichasia. Five sepals; five petals in a gamopetalous, zygomorphic
corolla, which is often bilabiate, but rarely to such an extent as in
the Labiatæ, and the upper lip in some is larger than the under, in
others smaller; stamens four didynamous, or two; the ovary is entire
(not grooved or divided), 1- or 2-locular, or, as in the Labiatæ,
divided into four loculi with an _erect_ ovule in each, but in some
the anterior carpel is suppressed. One _terminal_ style. The fruit is,
_e.g._ in _Verbena_, a 4 partite schizocarp with nut-like fruitlets;
in _Vitex_ (digitate leaves) a drupe with a 4-locular stone; in
_Clerodendron_ a similar fruit, with four free stones; in _Lantana_
a bilocular stone, or two unilocular stones. The radicle is _turned
downwards_. Endosperm small or absent.--_Lippia_, _Stachytarpheta_,
_Bouchea_, _Priva_, _Citharexylon_, _Callicarpa_, etc.--The Verbenaceæ
are closely allied to the Labiatæ; they differ especially in the ovary
not being 4-lobed with gynobasic style, but undivided, almost spherical
or ovoid with a terminal style. Again, the leaves are not so constantly
opposite, and the inflorescences are various.
730 species; especially in the Tropics; there are several in
America, especially _Lantana-species_; shrubby weeds.--Many of
those mentioned are ORNAMENTAL PLANTS, especially _Verbena_;
_Vitex agnus castus_ is a S. European shrub. _Lippia citriodora_
(S. Am.) etc., have strongly-scented leaves; the Teak tree
(_Tectona grandis_) is one of the largest trees in East India,
and has a very hard wood.
_Avicennia_ is allied to this order; it inhabits the Mangrove
swamps on tropical coasts. The endosperm emerges from the ovule,
carrying the embryo with it; the embryo ultimately bursts the
endosperm and lies free in the loculus of the fruit; this is
then filled by the embryo with its large, green cotyledons,
which are borne on an already hairy or rooted stem. The seedling
thus developed falls from the tree, together with the fruit, and
strikes root in the mud. One special cell of the endosperm at
an earlier period becomes a highly-developed organ of suction,
growing into a much-branched sac, very rich in protoplasm.
Order 4. =Labiatæ.= The special characteristics are: the _square_ stem,
the _opposite leaves_ (without stipules), the inflorescences which are
formed by _two double unipared scorpioid cymes_, the _labiate_ corolla,
the 4 _didynamous_ stamens (the posterior being entirely suppressed)
(Fig. 574), and the _4-partite schizocarp_ with _nut-like fruitlets_.
The floral formula is S5, P5, A5 (the posterior stamen is generally
absent), G2.
[Illustration: FIG. 574.--Diagram of _Lamium album_: _sv_
dichasia.]
They are chiefly aromatic plants (herbs, shrubs, _e.g._ Lavender,
or trees), volatile oil being formed in internal cells or in the
glandular hairs, which cover all green parts. The stem is always more
or less markedly square; the leaves are borne upon the flat sides,
and are simple and penninerved, but vary in the other characters.
The inflorescences are double unipared scorpioid cymes, which may
be situated at some distance from one another in the axils of the
foliage-leaves (Fig. 575 _A_), but frequently when the subtending
leaves are bract-like, they are crowded into spike-like inflorescences
(_Lavandula_, _Mentha_, _Salvia_, etc.), each of the so-called “whorls”
(verticillaster, glomerulus) being a double unipared scorpioid cyme
(Fig. 574). (Solitary flowers are found in _e.g._ _Scutellaria_, and
_Origanum_). The calyx is strongly gamosepalous, 5-toothed, often
bilabiate (Fig. 575 _B_). The corolla is strongly bilabiate (Figs. 575,
576, etc.), with 2 lobes in the upper lip and 3 lobes in the under lip
(an approach to regularity occurs only when the upper lip is small,
and thus resembles one lobe, as in _Mentha_ (Fig. 578) and _Lycopus_,
so that the corolla approaches the 4-merous corolla of _Veronica_
and _Plantago_). The posterior stamen in the diagram (Fig. 574*)
is entirely suppressed; in most of the genera the posterior lateral
stamens are the smaller (Fig. 575 _D_), and are entirely suppressed in
some (see below); in others, _e.g._ _Nepeta_, they are the longer. 2
stamens are found in _Salvia_, _Rosmarinus_, _Lycopus_, etc. The two
halves of the anthers are often separated from one another, and are
placed at an angle with each other. The gynœceum has 1 style with a
bifid extremity (Fig. 575 _C_) bearing the stigma; the true bilocular
ovary is divided by a false partition-wall into 4 loculi, each with 1
erect ovule (Fig. 575 _H_). These 4 loculi project so strongly that the
ovary becomes deeply 4-lobed with the style situated in the centre of
the lobes and at their base, “gynobasic” (Figs. 575, 579). A ring-like,
often crenate, nectary surrounds the base of the ovary (Fig. 575 _G_,
_H_). The embryo in this order, as in the _Verbenaceæ_, is directed
downwards (Fig. 575 _J_) (it is directed upwards in the _Boraginaceæ_,
which have an entirely similar fruit). _Endosperm absent._
[Illustration: FIG. 575.--_Thymus vulgaris._]
The 142 genera are mainly distinguished according to the form of
the calyx and corolla, the number, direction, and length of the
stamens, the forms of the nuts, etc.
=1.= AJUGEÆ, BUGLE GROUP. Calyx 10-nerved; the upper lip is small; 4
stamens. The ovary is not so strongly lobed as in the following group,
so that it is most nearly allied to the _Verbenaceæ_. The nuts are
reticulately wrinkled. _Ajuga_ (Bugle) has a very small upper lip. The
upper lip of _Teucrium_ (Germander) is deeply cleft, and the two lobes
are bent on their respective sides towards the under lip, which in
consequence appears to be 5-lobed, and the upper lip to be wanting.
[Illustration: FIG. 576.--_Lamium album_: _A_ lateral view of
flower; _B_ longitudinal section; _C_ ovary with nectaries (_a_);
_D_ the apex of the style; _e_, upper lip of corolla; _c_, _b_,
_c_ the three petals of the lower lip; _f_ anthers; _g_ stigma.]
=2.= STACHYDEÆ, BETONY GROUP. The calyx is 5- or 10-nerved. The
upper lip of the corolla is most frequently _strongly arched_ or
helmet-shaped; 4 stamens, the _anterior pair the longer_ (Fig. 576).
=a.= A somewhat regular and 5–10-dentate calyx with _projecting_
stamens.--_Stachys_ (Betony, Woundwort); the lobes of the under
lip are rounded off. The anterior filaments, after pollination,
_bend outwards_. _Betonica_--_Ballota_ (Horehound); the calyx
is funnel-shaped, and has triangular, long, pointed, awn-like
teeth.--_Galeopsis_ (Hemp-nettle) has two conical protuberances on the
under lip between the lateral and the central lobes. The anthers open
by 2 _unequal_ valves. _Lamium_ (Dead-nettle, Fig. 576) has dentate,
lateral lobes on the under lip. _L. album_ (White Dead-nettle), _L.
rubrum_, etc. _Galeobdolon._--_Leonurus_; _Phlomis_.
=b.= Tubular, regular, often 10-toothed calyx and _concealed_
stamens.--_Marrubium vulgare_ (Fig. 577); 10 calyx-teeth, hooked at
the apex; many almost spherical whorls of flowers in the axils of the
foliage-leaves, at some distance from one another.--_Sideritis._
[Illustration: FIG. 577.--_Marrubium vulgare._]
=c.= Strongly bilabiate calyx, the lips _closing together_ after
flowering.--_Scutellaria_ (Skull-cap); the two lips of the calyx are
entire, the upper lip has a large spur, and drops off on the ripening
of the fruit. The flowers are generally solitary and turned to one
side.--_Prunella_ (Heal-all); the calyx is compressed, its two lips are
strongly dentate, the upper lips closing slightly round the under. The
stamens have a tooth-like projection beneath the anthers.
=3.= NEPETEÆ, CATMINT GROUP. 13–15 nerves in the calyx; this deviates
from the other groups in the _posterior stamens being the longer_.
The upper lip is slightly arched. _Nepeta_ (Catmint), also _Glechoma_
(Ground Ivy), with regular, and _Dracocephalum_ with irregular calyx.
[Illustration: FIG. 578.--_Mentha aquatica_, var. _crispa_.]
=4.= SATUREIEÆ, MINT GROUP. The upper lip is _flat_, most frequently
ovate, or almost spherical, and emarginate (Fig. 578). The calyx
is most frequently 5–10-nerved. 4 stamens, _the anterior being the
longer_; rarely, 2 stamens only.--_Mentha_ (Mint, Fig. 578) has a
regular, 5-dentate calyx, a small, almost regular, 4-partite corolla,
and 4 erect stamens of nearly equal size. The verticillasters are
many-flowered, and are often collected into cylindrical inflorescences.
Herbs.--_Lycopus_ (Gipsy-wort); corolla almost regular. 2 stamens,
the posterior lateral ones are wanting. _Preslia_: 4-dentate calyx,
4-partite, regular corolla; 4 stamens of equal size.--_Thymus_ (Thyme,
Fig. 575) has a strongly bilabiate calyx, the throat being closed by
a whorl of hairs (Fig. 575 B). The corolla is distinctly labiate.
Under-shrubs, with small entire leaves; verticillasters few-flowered
and separate.--_Origanum_ (Marjoram); spike or capitate inflorescences
with the flowers solitary in the axils of the rather large and
distinctly 4-rowed (often slightly coloured) floral-leaves. _Melissa._
_Calamintha._ _Clinopodium_ (Wild Basil). _Satureia._ _Hyssopus_
(Hyssop); small, entire leaves; the verticillasters are situated
unilaterally in a slender, spike-like inflorescence. _Lavandula_
(Lavender); shrubs with verticillasters collected in cylindrical,
long-stalked inflorescences; the calyx is tubular, has 13–15 nerves,
the posterior tooth is much larger than the others. Stamens and style
do _not_ project. ~_Coleus_ differs, among other characters, in having
united filaments; the stamens and style are bent down and concealed in
the boat-shaped under lip.~
[Illustration: FIG. 579.--_Salvia officinalis._]
=5.= MONARDEÆ, SALVIA GROUP. _Only the 2 anterior stamens are
developed._--_Salvia_ (Fig. 579); calyx deeply bilabiate; the upper
lip of the corolla is generally strongly compressed. Rudiments of
the two lateral stamens are present. The connective in the two
fertile stamens is long and filamentous, and bears at the upper end
a normal half-anther, but at the lower one a barren, often broader
portion, against which the insect is obliged to push its proboscis
during its visits to the flowers, causing the pollen-bearing
half-anther to be pressed down against its back. Floral-leaves often
coloured.--_Rosmarinus_ (Rosemary); a shrub with leathery linear
leaves, with rolled back edge. A small tooth on the filament represents
the barren half of the anther. _Monarda._
The POLLINATION is generally effected by insects, especially
bees; the under-lip is the landing-stage and the pollen is
deposited on their backs. Cross-fertilisation is promoted by
dichogamy; honey is secreted by an hypogynous disc and collected
in the corolla-tube. Some genera are homogamous (_Lamium_,
_Galeopsis_, etc.); others are dichogamous (protandrous); a
few are _gynodiœcious_: ♀-and ☿-flowers in various relative
sizes (_Glechoma hederaceum_, _Thymus_, _Salvia pratensis_,
and others). The entrance of uninvited guests to the honey is
often rendered difficult by whorls of hairs, etc. In numerous
instances the upper lip protects the pollen from rain.
_Cleistogamy_ is found _e.g._ in _Lamium amplexicaule_.
2,700 species; distributed over the entire globe, but the
greater number in Mediterranean countries (especially in the
Eastern regions), where many are shrub-like.--Poisonous and
acrid properties are absent. On account of their _volatile oils_
they are principally used as _condiments_, for _perfumery_
and in _medicine_ (the officinal parts are therefore nearly
always “folia” and “herba,” in _Lavandula_ the flowers, and
the volatile oils extracted from them). Such are:[39]_Mentha
piperita_ [+] (Peppermint)--menthol is obtained from this
species and from _M. arvensis_--_M. viridis_ [+] (Spearmint),
_M. crispa_ (Curly-mint), _Thymus vulgaris_ (Garden Thyme),
_Melissa officinalis_ (S. Eur.), _Hyssopus officinalis_
(Hyssop, S. Eur.), _Origanum majorana_ (Marjoram, from the
Mediterranean), _O. vulgare_ (Wild Marjoram), _creticum_,
_smyrnæum_, etc., _Salvia officinalis_ (S. Eur.), _Rosmarinus
officinalis_ (oil of Rosemary, S. Eur.), _Lavandula vera_ [+]
(oil of Lavender, S. Eur.). Also: _Satureia hortensis_ (S.
Eur.), _Ocimum basilicum_ (E. India), _Pogostemon patchouli_
(E. India), etc.--As _ornamental_ plants, _e.g._ _Monarda_,
_Plectranthus_, and _Coleus_ (foliage-plants, often with red
stems and leaves), _Stachys lanata_ (white, woolly), _Phlomis_,
_Salvia_-species, _Perilla_, etc.
Order 5. =Selaginaceæ.= 130 species; small, most frequently
heath-like shrubs or herbs, mainly from S. Africa. They
differ from the other Nuculiferæ especially in the bilocular,
transversely-placed anthers of the 4 stamens (2 stamens
divided as far as the base (?)). The ovary has 2, or by
suppression only 1 loculus, each with 1 ovule, and the fruit
is a schizocarp dividing into two, or is a 1-seeded nut.
Radicle turned upwards.--A few are ornamental plants (_Selago_,
_Hebenstreitia_).
Order 6. =Globulariaceæ.= 12 species; especially in the
Mediterranean. They form an analogy to the Compositæ, and in the
main resemble _Jasione montana_ in appearance, the flowers being
crowded into a spherical head (hence their name) and supported
by bracts, but _without_ involucre; the ovary is _unilocular_
with 1 pendulous ovule. The _1-seeded nut_ is enveloped by the
persistent calyx. The corolla is more or less labiate, the
upper-lip is often absent as in the ligulate corollas of the
Astereæ; stamens 4, didynamous, with transversely placed anthers
opening by one transverse cleft. The leaves are scattered,
simple, entire, and generally form a rosette. _Globularia._
Order 7. =Stilbaceæ.= Heath-like shrubs. The ovary is bilocular;
1 erect seed in each loculus, or the posterior cell is empty.
_Stilbe._ 7 species. S. Africa.