striking in the celebrated Torito of South America (our Anguloa
grandiflora); in the Mosquito (our Restrepia antennifera); in the Flor
del Espiritu Santo (also an Anguloa, according to Floræ Peruvianæ
Prodrom. p. 118, tab. 26); in the ant-like flower of the Chiloglottis
cornuta (Hooker, Flora antarctica, p. 69); in the Mexican Bletia
speciosa; and in the highly curious host of our European species
of Ophrys: O. muscifera, O. apifera, O. aranifera, O. arachnites,
&c. A predilection for this superbly flowering group of plants has
so increased, that the number cultivated in Europe by the brothers
Loddiges in 1848 has been estimated at 2360 species; while in 1843 it
was rather more than 1650, and in 1813 only 115. What a rich mine of
still unknown superb flowering Orchideæ the interior of Africa must
contain, if it is well watered! Lindley, in his fine work entitled “The
Genera and Species of Orchideous Plants,” described in 1840 precisely
1980 species; at the end of the year 1848 Klotzsch reckoned 3545
species.
While in the temperate and cold zones there are only “terrestrial”
Orchideæ, _i. e._ growing on and close to the ground, tropical
countries possess both forms, _i. e._ the “terrestrial” and the
“parasitic,” which grow on trunks of trees. To the first-named of
these two divisions belong the tropical genera Neottia, Cranichis,
and most of the Habenarias. We have also found both forms growing as
alpine plants on the slopes of the chain of the Andes of New Granada
and Quito: of the parasitical Orchideæ (Epidendreæ), Masdevallia
uniflora (at 9600 French, or about 10230 English feet); Cyrtochilum
flexuosum (at 9480 French, or about 10100 English feet); and Dendrobium
aggregatum (8900 French, or about 9480 English feet): and of the
terrestrial Orchideæ, the Altensteinia paleacea, near Lloa Chiquito,
at the foot of the Volcano of Pichincha. Claude Gay thinks that the
Orchideæ said to have been seen growing on trees in the Island of
Juan Fernandez, and even in Chiloe, were probably in reality only
parasitical Pourretias, which extend at least as far south as 40° S.
lat. In New Zealand we find that the tropical form of Orchideæ hanging
from trees extends even to 45° S. lat. The Orchideæ of Auckland’s and
Campbell’s Islands, however (Chiloglottis, Thelymitra, and Acianthus),
grow on the ground in moss. In the animal kingdom, one tropical form
at least advances much farther to the south. In Macquarie Island, in
lat. 54° 39´, nearer to the South Pole therefore than Dantsic is to the
North Pole, there is a native parrot. (See also the section Orchideæ in
my work de Distrib. geogr. Plant., pp. 241-247.)
[22] p. 25.--“_The Casuarinæ._”
Acacias which have phyllodias instead of leaves, some Myrtacesæ
(Eucalyptus, Metrosideros, Melaleuca, and Leptospermum), and
Casuarinas, give a uniform character to the vegetation of Australia
and Tasmania (Van Diemen Island). Casuarinas with their leafless,
thin, string-like, articulated branches, having the joints provided
with membranous denticulated sheaths, have been compared by travellers,
according to the particular species which fell under their observation,
either to arborescent Equisetaceæ (Horsetails) or to our Scotch firs.
(See Darwin, Journal of Researches, p. 449.) Near the coast of Peru
the aspect of small thickets of Colletia and Ephedra also produced on
my mind a singular impression of leaflessness. Casuarina quadrivalvis
advances, according to Labillardière, to 48° S. lat. in Tasmania. The
sad-looking Casuarina form is not unknown in India and on the east
coast of Africa.
[23] p. 25.--“_Needle-leaved trees._”
The family of Coniferæ holds so important a place by the number of
individuals, by their geographical distribution, and by the vast
tracts of country in the northern temperate zone covered with trees
of the same species living in society, that we are almost surprised
at the small number of species of which it consists,--even including
members which belong to it in essential respects, but deviate from it
in a degree by the shape of their leaves and their manner of growth
(Dammara, Ephedra, and Gnetum, of Java and New Guinea). The number
of known Coniferæ is not quite equal to three-fourths of the number
of described species of palms; and there are more known Aroideæ than
Coniferæ. Zuccarini, in his Beiträgen zur Morphologie der Coniferen
(Abhandl. der mathem. physikal. Classe der Akademie der Wiss. zu
München, Bd. iii. S. 752, 1837-1843), reckons 216 species, of which
165 belong to the northern and 51 to the southern hemisphere. Since my
researches these proportionate numbers must be modified, as, including
the species of Pinus, Cupressus, Ephedra, and Podocarpus, found by
Bonpland and myself in the tropical parts of Peru, Quito, New Granada,
and Mexico, the number of species between the tropics rises to 42. The
most recent and excellent work of Endlicher, Synopsis Coniferarum,
1847, contains 312 species now living, and 178 fossil species found in
the coal measures, the bunter-sandstone, the keuper, and the Jurassic
formations. The vegetation of the ancient world offers to us more
particularly forms which, by their simultaneous affinity with several
different families of the present vegetable world, remind us that many
intermediate links have perished. Coniferæ abounded in the ancient
world: their remains, belonging to an early epoch, are found especially
in association with Palms and Cycadeæ; but in the latest beds of
lignite we also find pines and firs associated as now with Cupuliferæ,
maples, and poplars. (Kosmos, Bd. i. S. 295-298, and 468-470; Engl.
edit. p. 271-274, and lxxxix.)
If the earth’s surface did not rise to considerable elevations within
the tropics, the highly characteristic form of needle-leaved trees
would be almost unknown to the inhabitants of the equatorial zone. In
common with Bonpland I have laboured much in the determination of the
exact lower and upper limits of the region of Coniferæ and of oaks in
the Mexican highlands. The heights at which both begin to grow (los
Pinales y Encinales, Pineta et Querceta) are hailed with joy by those
who come from the sea-coast, as indicating a climate where, so far as
experience has hitherto shewn, the deadly malady of the black vomit
(Vomito prieto, a form of yellow fever) does not reach. The lower limit
of oaks, and more particularly of the Quercus xalapensis (one of the
22 Mexican species of oak first described by us), is on the road from
Vera Cruz to the city of Mexico, a little below the Venta del Encero,
2860 (3048 E.) feet above the sea. On the western side of the highlands
between the city of Mexico and the Pacific, the limit is rather
lower down, for oaks begin to be found near a hut called Venta de la
Moxonera, between Acapulco and Chilpanzingo, at an absolute elevation
of 2328 (2480 E.) feet. I found a similar difference in the height of
the lower limit of pine woods on the two-sides of the continent. On
the Pacific side, in the Alto de los Caxones north of Quaxiniquilapa,
we found this limit for Pinus Montezumæ (Lamb.), which we at first
took for Pinus occidentalis (Swartz), at an elevation of 3480 (3709
E.) feet; while towards Vera Cruz, on the Cuesta del Soldado, pines
are first met with at a height of 5610 (5950 E.) feet. Therefore both
the kinds of trees spoken of above, oaks and pines, descend lower on
the side of the Pacific than they do on the side of the Antillean sea.
In ascending the Cofre di Perote, I found the upper limit of the oaks
9715 (10354 E.) feet, and that of the Pinus Montezumæ at 12138 (12936
E.) feet above the sea, or almost 2000 (2132 E.) feet higher than the
summit of Etna. Considerable quantities of snow had fallen at this
elevation in the month of February.
The more considerable the heights at which the Mexican Conifers are
first met with, the more striking it appears to find in the Island
of Cuba (where, indeed, on the borders of the torrid zone, northern
breezes sometimes cool the atmosphere down to 6-1/2° Reaumur, 46°.6
Fah.), another species of pine (P. occidentalis of Swartz), growing in
the plains or on the low hills of the Isla de Pinos, intermixed with
palms and mahogany trees (Swietenias). Columbus mentions a small pine
wood (Pinal) in the journal of his first voyage (Diario del 25 de Nov.
1492), near Cayo de Moya, on the north-east of the Island of Cuba.
In Hayti also, Pinus occidentalis descends from the mountains to the
sea-shore, near Cape Samana. The trunks of these Pines, carried by the
Gulf-stream to the Islands of Graciosa and Fayal in the Azores, were
among the chief indications from which the great discoverer inferred
the existence of unknown lands to the west. (See my Examen crit.,
T. ii. p. 246-259.) Is it true that in Jamaica, notwithstanding the
height of its mountains, Pinus occidentalis is entirely wanting? We
may also ask what is the species of Pinus found on the eastern coast
of Guatimala, as P. tenuifolia (Benth.) probably belongs only to the
mountains near Chinanta?
If we cast a general glance on the species which form the upper limits
of arborescent vegetation in the northern hemisphere, from the frigid
zone to the equator, we find, beginning with Lapland, that according to
Wahlenberg, on the Sulitelma Mountain (lat. 68°) it is not needle-trees
which form the upper limit, but that birches (Betula alba) extend much
higher up than Pinus sylvestris;--whilst in the temperate zone, in the
Alps (lat. 45-3/4°), Pinus picea (Du Roi) advances highest, leaving
the birches behind; and in the Pyrenees (lat. 42-1/2°), Pinus uncinata
(Ram.) and P. sylvestris var. rubra: within the tropics, in lat.
19°-20° in Mexico, Pinus Montezumæ leaves far behind Alnus toluccensis,
Quercus spicata, and Q. crassipes; while in the snow mountains of Quito
at the equator, Escallonia myrtilloides, Aralia avicennifolia, and
Drymis winteri, take the lead. The last-named tree, which is identical
with Drymis granatensis (Mut.) and Wintera aromatica (Murray),
presents, as Joseph Hooker has shewn (Flora Antarctica, p. 229), the
striking example of the uninterrupted extension of the same species of
tree from the most southern part of Tierra del Fuego and Hermit Island,
where it was discovered by Drake’s Expedition in 1577, to the northern
highlands of Mexico; or through a range of 86 degrees of latitude, or
5160 geographical miles. Where it is not birches (as in the far north),
but needle trees (as in the Swiss Alps and the Pyrenees), which form
the limit of _arborescent_ vegetation on the highest mountains, we find
above them, still nearer to the snowy summits which they gracefully
enwreath with their bright garlands, in Europe and Western Asia, the
Alp roses, the Rhododendra,--which are replaced on the Silla de Caracas
and in the Peruvian Paramo de Saraguru by the purple flowers of another
genus of Ericaceæ, the beautiful race of Befarias. In Lapland the
needle-trees are immediately followed by Rhododendron laponicum; in the
Swiss Alps by Rhododendron ferrugineum and R. hirsutum; in the Pyrenees
by the R. ferrugineum only; and in the Caucasus by R. caucasicum.
Decandolle found the Rhododendron ferrugineum growing singly in the
Jura (in the Creux de Vent) at the moderate altitude of 3100 to 3500
(3304 to 3730 E.) feet, 5600 (5968 E.) feet lower down than its proper
elevation. If we desire to trace the last zone of vegetation nearest to
the snow line in the tropics, we must name, from our own observations,
in the Mexican part of the tropical zone, Cnicus nivalis and Chelone
gentianoides; in the cold mountain regions of New Granada, the woolly
Espeletia grandiflora, E. corymbosa and E. argentea; and in the Andes
of Quito, Culcitium rufescens, C. ledifolium, and C. nivale,--yellow
flowering Compositæ which replace in the last-named mountains the
somewhat more northerly Espeletias of New Granada, to which they bear
a strong physiognomic resemblance. This replacement, the repetition
of resembling or almost similar forms in countries separated either
by seas or by extensive tracts of land, is a wonderful law of nature
which appears to prevail even in regard to some of the rarest forms of
vegetation. In Robert Brown’s family of the Rafflesieæ, separated from
the Cytineæ, the two Hydnoras described by Thunberg and Drege in South
Africa (H. africana and H. triceps) have their counterpart in South
America in Hydnora americana (Hooker).
Far above the region of alpine plants, grasses, and lichens, and even
above the limit of perpetual snow, the botanist sees with astonishment,
both in the temperate and tropical zones, isolated phænogamous plants
occur now and then sporadically on rocks which remain free from the
general surrounding snowy covering, and which may possibly be warmed
by heat ascending through open fissures. I have already spoken of
the Saxifraga boussingaulti, which is found on the Chimborazo at an
elevation of 14800 (15773 E.) feet; in the Swiss Alps, Silene acaulis
has been seen at a height of 10680 (11380 E.) feet, being in the
first-named case 600 (640 E.) feet, and in the second 2460 (2620 E.)
feet above the limit of the snows, that limit being taken as it was in
the two cases respectively at the time when the plants were found.
In our European Coniferæ, the Red and White Pine shew great and
remarkable differences in respect to their distribution. While
in the Swiss Alps the Red Pine (Pinus picea, Du Roi, foliis
compresso--tetragonis; unfortunately called by Linnæus, and by most of
the botanists of the present day, Pinus abies!) forms the upper limit
of arborescent vegetation at a mean height of 5520 (5883 English) feet,
only an occasional low growing mountain-alder (Alnus viridis, Dec.,
Betula viridis, Vill.) advancing now and then still nearer to the
snow-line; the White Pine (Pinus abies, Du Roi, Pinus picea, Linn.,
foliis planis, pectinatodistichis, emarginatis) ceases, according to
Wahlenberg, more than a thousand feet lower down. The Red Pine does not
appear at all in the South of Europe, in Spain, the Appennines, and
Greece; even on the northern slope of the Pyrenees it is seen only, as
Ramond remarks, at great elevations, and is entirely wanting in the
Caucasus. The Red Pine advances in Scandinavia farther to the north
than the White Pine, of which last-named tree there is in Greece (on
Mounts Parnassus, Taygetus, and Œta) a long needled variety (foliis
apice integris, breviter mucronatis), the Abies Apollinis of Link.
(Linnæa, Bd. xv. 1841, S. 529; and Endlicher, Synopsis Coniferarum, p.
96.)
On the Himalaya the Coniferæ are distinguished by the great thickness
and height of their trunks, and by the length of their leaves. The
Deodwara Cedar, Pinus deodara (Roxb.),--(properly, in Sanscrit,
dêwa-dâru, timber of the Gods),--which is from 12 to 13-1/2 feet
thick, is the great ornament of the mountains. It grows in Nepaul to
11000 (11720 E.) feet above the level of the sea. More than 2000 years
ago the Deodara supplied the materials for the fleet of Nearchus on
the Hydaspes (the present Behut). In the valley of Dudegaon, north
of the copper mines of Dhunpour in Nepaul, Dr. Hoffmeister, so early
lost to science, found the Pinus longifolia of Royle (the Tschelu
Pine) growing among tall stems of the Chamærops martiana of Wallich.
(Hoffmeister’s Briefe aus Indien während der Expedition des Prinzen
Waldemar von Preussen, 1847, S. 351.) Such an intermixture of pineta
and palmata had excited the surprise of the companions of Columbus in
the New Continent, as a friend and cotemporary of the Admiral, Petrus
Martyr Anghiera, has informed us. (Dec. iii. lib. 10, p. 68.) I saw
myself this intermixture of pines and palms for the first time on the
road from Acapulco to Chilpanzingo. The Himalaya, like the Mexican
highlands, has, besides Pines and Cedars, also the forms of Cypresses
(Cupressus torulosa, Don), of Yews (Taxus wallichiana, Zuccar.), of
Podocarpus (P. nereifolia, Robert Brown), and of Juniper (Juniperus
squamata, Don., and J. excelsa, Bieberst; Juniperus excelsa is also
found at Schipke in Thibet, in Asia Minor, in Syria, and in the Greek
Islands). Thuja, Taxodium, Larix, and Araucaria, are forms found in the
New Continent, but wanting in the Himalaya.
Besides the 20 species of Pines which we already know from Mexico,
the United States of North America, which in their present extent
reach to the Shores of the Pacific, have 45 described species, while
Europe has only 15. There is a similar difference in respect to Oaks:
_i. e._ greater variety of forms in the New Continent which extends
continuously through a greater extent of latitude. The recent very
exact researches of Siebold and Zuccarini have, however, completely
refuted the previous belief, that many European species of Pines extend
also across the whole of Northern Asia to the Islands of Japan, and
even grow there, interspersed, as Thunberg has stated, with genuine
Mexican species, the Weymouth Pine, Pinus Strobus of Linnæus. What
Thunberg took for European Pines are wholly different and distinct
species. Thunberg’s Red Pine (Pinus abies, Linn.) is P. polita, (Sieb.)
and is often planted near Buddhistic temples; his common Scotch Fir
(Pinus sylvestris) is P. Massoniana (Lamb.); his P. cembra (the German
and Siberian pine with eatable seeds) is P. parviflora (Sieb.); his
common Larch (P. larix) is P. leptolepis (Sieb.); and his supposed
Taxus baccata, the fruits of which are eaten by Japanese courtiers in
case of long-protracted court ceremonials, (Thunberg, Flora Japonica,
p. 275), constitutes a distinct genus, and is the Cephalotaxus drupacea
of Siebold. The Islands of Japan, notwithstanding the vicinity of
the Continent of Asia, have a very distinct character of vegetation.
Thunberg’s supposed Japanese Weymouth Pine, (Pinus Strobus) which
would offer an important phenomenon, is only a planted tree, and is
besides quite distinct from the American species of Pine. It is Pinus
korajensis (Sieb.), and has been brought to Nipon from the peninsula of
Corea, and from Kamtschatka.
Of the 114 species of the Genus Pinus with which we are at present
acquainted, not one belongs to the Southern Hemisphere, for the Pinus
merkusii described by Junghuhn and De Vriese belongs to the part of
the Island of Sumatra which is north of the Equator, to the district
of the Battas; and Pinus insularis (Endl.) although it was at first
given in Loudon’s Arboretum as P. timoriensis, really belongs to
the Philippines. Besides the Genus Pinus, the Southern hemisphere,
according to the present state of our now happily advancing knowledge
of the geography of plants, is entirely without species of Cupressus,
Salisburia (Gingko), Cunninghamia (Pinus lanceolota, Lamb.) Thuja,
(one of the species of which, Th. gigantea, Nutt., found on the banks
of the Columbia, has a height of above 180 Eng. feet), Juniperus,
and Taxodium (Mirbel’s Schubertia). I include the last-named genus
with the less hesitation, as a Cape of Good Hope plant (Sprengel’s
Schubertia capensis) is no Taxodium, but constitutes a genus of itself,
Widringtonia, (Endl.) in quite a different division of the family of
Coniferæ.
This absence, from the Southern Hemisphere, of true Abietineæ,
Juniperineæ, Cupressineæ, and all the Taxodineæ, as well as of
Torreya, Salisburia adiantifolia, and Cephalotaxus from among the
Taxineæ, recalls forcibly the obscurity which still prevails in the
conditions which have determined the original distribution of vegetable
forms, a distribution which cannot be sufficiently and satisfactorily
explained solely by similarity or diversity of soil, thermic relations,
or meteorological phenomena. I remarked long ago that the Southern
Hemisphere for example has many plants belonging to the natural family
of Rosaceæ, but not a single species of the genus Rosa. We learn from
Claude Gay that the Rosa chilensis described by Meyen is only a wild
variety of the Rosa centifolia (Linn.), which has been for thousands of
years a European plant. Such wild varieties, (_i. e._ varieties which
have become wild) occupy large tracts of ground in Chili, near Valdivia
and Osorno. (Gay, Flora Chilensis, p. 340.)
In the tropical region of the Northern hemisphere we also found only
one single native rose, our Rosa montezumæ, in the Mexican highlands
near Moran, at an elevation of 8760 (9336 Engl.) feet. It is one of
the singular phenomena in the distribution of plants, that Chili,
which has Palms, Pourretias, and many species of Cactus, has no Agave;
although A. americana grows luxuriantly in Roussillon, near Nice, near
Botzen and in Istria, having probably been introduced from the New
Continent since the end of the 16th century, and in America itself
forms a continuous tract of vegetation from Northern Mexico across the
isthmus of Panama to the Southern part of Peru. I have long believed
that Calceolarias were limited like Roses exclusively to one side of
the Equator; of the 22 species which we brought back with us, not one
was collected to the north of Quito and the Volcano of Pichincha; but
my friend Professor Kunth remarks that Calceolaria perfoliata, which
Boussingault and Captain Hall found at Quito, advances to New Granada,
and that this species, as well as C. integrifolia of Santa Fé de
Bogotá, were given by Mutis to the great Linnæus.
The species of Pinus which are so frequent in the tropical Antilles and
in the tropical mountains of Mexico do not pass the isthmus of Panama,
and are not found in the equally mountainous parts of the tropical
portion of South America, and in the high plains of New Granada, Pasto,
and Quito. I have been both in the plains and on the mountains from the
Rio Sinu, near the isthmus of Panama, to 12° S. lat.; and in this tract
of almost 1600 geographical miles the only forms of needle-trees which
I saw were a Taxus-like species of Podocarpus with stems 60 (64 Eng.)
feet high (Podocarpus taxifolia), growing in the Pass of Quindiu and in
the Paramo de Saraguru, in 4° 26´ north, and 3° 40´ south latitude; and
an Ephedra (E. americana) near Guallabamba, north of Quito.
Among the Coniferæ there are common to the northern and southern
hemispheres the genera Taxus, Gnetum, Ephedra, and Podocarpus. The
last-named genus was distinguished from Pinus long before L’Heritier
by Columbus himself, who wrote on the 25th of November, 1492: “Pinales
en la Serrania de Haiti que no llevan piñas, pero frutos que parecen
azeytunos del Axarafe de Sevilla.” (See my Examen crit. T. iii. p. 24.)
There are species of Taxus from the Cape of Good Hope to 61° N. lat. in
Scandinavia, or through more than 95 degrees of latitude; Podocarpus
and Ephedra extend almost as far. In Cupuliferæ, the species of oak
which we are accustomed to regard as a northern form do not indeed pass
beyond the equator in South America, but in the Indian Archipelago they
re-appear in the southern hemisphere in the Island of Java. To the
southern hemisphere belong exclusively ten genera of Coniferæ, of which
I will name here only the principal: Araucaria, Dammara (Agathis Sal.),
Frenela (with eighteen New Holland species), Dacrydium and Lybocedrus,
which is found both in New Zealand and at the Straits of Magellan. New
Zealand has one species of the genus Dammara (D. australis) and no
Araucaria. In New Holland in singular contrast the case is opposite.