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AN OUTLINE OF PLANT GEOGRAPHY 



THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAOO • DALLAS 
ATLANTA • SAN FRANCISCO 

MACMILLAN <fe CO., Limited 

LONDON • BOMBAY • CALCUTTA 
MELBOURNE 

THE MACMILLAN CO. OF CANADA, Ltd. 

TORONTO 



AN OUTLINE 



OF 



PLANT GEOGRAPHY 



BY 
DOUGLAS HOUGHTON CAMPBELL 



THE MACMILLAN COMPANY 

1926 

All rights reserved 



Copyright, 1926. 
By THE MACMILLAN COMPANY 



Set up and electrotyped. 
Published April, 1926. 



PRINTED IN THE UNITED STATES OF AMERICA BY 
THE BERWICK & SMITH CO. 




PREFACE 

To the lover of Nature, whether scientist or layman, one of 
the greatest charms of travel is seeing the many new and Into 
ing plants inhabiting the various parts of the world. 

For a good many years the writer has had occasion to visit 
many countries in the quest of material for his botanical studii 
and although these investigations, for the mosl part, have not 
been concerned primarily with plant distribution, nevertheless the 
general vegetation of the various places visited, and the relations 
of the different floras to each other, have always been subjecl 
the greatest interest. 

Moreover, for some years past, these botanical excursions hi 
been devoted to a considerable extent directly to problems of 
plant distribution; and although the writer can hardly lay claim 
to rank as a plant geographer, he has nevertheless contributed in 
a small way to the subject. 

It is conceivable that one who is, in a way, an amateur may I e 
more likely to appreciate the more salient features of a flora than 
the specialist in some particular group of such a flora: and this 
may be offered as an explanation of the writer- venturing into a 
field where he can scarcely expect to be looked upon as an expert. 

In a volume of moderate size dealing with so vast a subj< 
plant geography, it is obvious that anything beyond a -ketch i- 
impossible; but it is hoped that the outline offered here will pin 
sufficiently clear and accurate to give a fairly satisfactory picture 
of the most notable features of the vegetation characteristic of 
the more important botanical regions, lor the minuter details. 
of course, one must refer to the many treatises dealing with the 
floras of special countries. 

For more than thirty years the writer has made excursions into 
many parts of the world, and the specimens, notes, sketches and 
photographs accumulated during these journeys, have served 
the basis of the present volume. These personal data have l.< ■ 
supplemented by free use of such standard general work 
of Drude and Schimper, as well as the descriptive floras of many 

v 



vi PREFACE 

regions, and numerous special monographs and papers dealing 
with plant distribution by American botanists and those of other 
countries. The important series of monographs "Die Vegetation 
der Erde" has been found especially helpful, and the well-known 
"Naturliche Pflanzenfamilien " of Engler and Prantl has been 
frequently consulted. 

A considerable number of important photographs which have 
added materially to the value of the book, were furnished through 
the courtesy of colleagues and others, to all of whom the writer 
is greatly indebted and would express his sincere thanks. Due 
credit is given in each case. 

It is hoped that the volume will not prove too technical to be 
of value to the general reader interested in the subject of plant 
distribution; but the writer has tried to make it sufficiently de- 
tailed to be useful, also, as a book of reference for botanists, or 
as a text in classes studying the general subject of plant geography. 

Douglas Houghton Campbell. 

Stanford University, 
February, 1926. 



CONTENTS 

Pi 

Chapter I — Introduction 1 

The Geological Record 

Succession of Plants in Geological Time 4 

The First Land Plants 7 

Existing Factors in Distribution [g 

Man and the Plant World 17 

Chapter II — Climatic Zones 

The Boreal Regions 

The Arctic Zone j; 

The Sub-arctic : ; 1 

Alaska 

Chapter III — The North Temperate Zone \:> 

Eurasia and North Africa 

Western and Central Europe }•; 

The British Islands ."1 

The Mediterranean Flora 

The Iberian Peninsula 5 1 

Northern Africa 

The Atlantic Islands 

The Eastern Mediterranean 

The Himalayan Regions 

Eastern Asia 7 1 

Japan 7 8 

Siberia . , 

Chapter IV — North Temperate Zone (continued B4 

Atlantic and Central United States and Canada 

Eastern United States and Canada ss 

The Coastal Plain 100 

The Gulf States I< 

The Prairie Region 1 ( ' 

Florida HO 

vii 



J 



viii CONTEXTS 

PAGE 

Chapter V — The North Temperate Zone (concluded) 114 
The tiocky Mountains and Pacific Slope 

The Rocky Mountains 114 

The Great Basin 120 

The Pacific Coast 125 

British Columbia and Puget Sound 129 

California 132 

The Mojave Desert 144 

The Sierra Nevada 145 

Southern California and the Colorado Desert 151 

Chapter VI — The Palaeotropics 157 

Africa and Continental Asia 

Tropical Africa 157 

Equatorial West Africa 159 

Tropical East Africa 163 

Portuguese West Africa 165 

The Great Kamerun 166 

East Central Africa 169 

The Asiatic Tropics 176 

Arabia 176 

India 177 

The Indus Plain 179 

The Gangetic Plain, Bengal 181 

Assam and Upper Burma 185 

The Western Ghats • . 186 

Ceylon 187 

Indo-China 194 

The Islands of the Indian Ocean, Madagascar 197 

The Seychelles 199 

Chapter VII — The Palaeotropics (continued) 200 

Malaija and Polynesia 

Malay Peninsula 200 

Singapore 204 

The Sunda Islands 210 

Borneo 210 

Sumatra 218 



CONTENTS 



IX 



Java 224 

Krakatau 

The Philippines 

Austro-Malaya, Papua 241 

North Australia 243 

Polynesia 249 

Hawaii 255 

Chapter VIII — The Neotropical Regions 

Mexico 263 

Central America 

South America 27 1 

The Amazon Forest 271 

Brazilian Highlands 282 

Andean Forest 28 

Guiana 2 

Trinidad 294 

The Galapagos Islands 3< N I 

The Antilles 301 

Chapter IX — The South Temperate Zone 306 

South Africa — Cape Region 

Natal 313 

Transvaal 317 

Kalahari Desert 320 

Karroo 

Australasia 321 

Australia ; • 

New Zealand 

The Sub-antarctic Flora 349 

Agriculture and Horticulture in Australasia 

Temperate South America 355 

Fuegia 

Chile ;: 

The Chilean Oceanic Islands 

Index 



AN OUTLINE OF PLANT GEOGRAPHY 



OUTLINE OF PLANT GEOGRAPHY 



CHAPTER I 

INTRODUCTION 

As one studies the existing vegetation of the Earth, one I 
nizes certain factors whose influence in determining the < list ribution 
of the species composing this vegetation is sufficiently clear; but 
there are other factors quite as potent which are by no means - i 

obvious. 

Of course for the existence of normal green plants, a certain 
minimum of light, heat and moisture is essential; and up to a 
certain point the luxuriance of vegetation is in direct ratio to the 
relation of these three factors, and culminates where all work 
together, as in the equatorial regions of both hemispheres. 

The soil constituents are also very evident factors in determining 
the distribution of many species. Certain plants like rhododen- 
drons and others of the heath family, are notoriously impatient 
of lime, and only thrive in acid soils. Others like lettuce, aspara- 
gus, clover, demand lime in the soil as a condition for their healthy 
growth. Heavy clay soils suit some plants, light sandy soils are 
indispensable for others. 

Conditions in widely separated regions may be very similar. 
but this by no means implies a close relationship of the vegetation 
between these regions, although its general aspect may be much 
the same. Thus the rain forests of the Amazon Valley, and th 
of Borneo or Java, look much alike-lofty trees draped with 
lianas, orchids and other epiphytes, with an undergrowth of 
palms, huge ferns, arums and other large leaved growths like the 
bananas and gingers. In spite of this cl< ueral resemblam 

probably there would not be a single species common to the two 
regions. So in the temperate parts of Europe and North America 
there are relatively few common species, although the floras ha 
much in common, and are obviously related to each other. 

1 



2 OUTLINE OF PLANT GEOGRAPHY 

The main problem of the student of plant geography is to dis- 
cover, if possible, the explanation of the diverse floras of the dif- 
ferent parts of the earth, as well as resemblances which occur 
in widely sundered lands. 

Could we know the whole history of the evolution of the plant 
kingdom, this problem would be simple enough; but our knowledge 
of the vegetation of the earliest geological periods is almost nil; 
and it is not until a comparatively late period that we have any 
certain evidences of the nature of the vegetation. 

As we study such relics of the ancient floras as have come to 
us in a fossil state, we realize that the distribution of land and 
water upon the earth's surface has undergone many and extensive 
changes. Lands once connected are now widely sundered, and 
regions now united were separated by great expanses of ocean. 
Continents have sunk beneath the ocean, and lofty mountain 
chains have emerged from the ancient seas. 

These changes in the distribution of land and water have doubt- 
less had much to do with the fluctuations of climate indicated by 
a study of the ancient rocks and fossils. These reveal the presence 
of luxuriant vegetation in regions now quite impossible for its 
existence. Within a few degrees of the poles, in both hemispheres, 
fossil plants have been found which must have grown in a climate 
at least temperate in character. 

A study of these evident changes in climate and topography 
and the fossils that have been discovered, have thrown much 
light on many facts in the present distribution of plants, that 
otherwise would be quite incomprehensible. 

While the fossil record is very incomplete, nevertheless it has 
greatly helped in our understanding of the relations existing be- 
tween the vegetation of regions now widely separated but which 
we know were once connected. 

However, much more must be done in the study of the 
fossil plants of many parts of the world before we shall be in 
a position to solve some of the most difficult questions of dis- 
tribution which remain to be answered. It is to be hoped that 
in course of time with our increasing knowledge of the ancient 
floras of the more remote parts of the world, that we may 
solve some of the many puzzles in the distribution of existing 
plants. 



INTRODUCTION 



The Geological Record 



A study of the fossil plants shows beyond question thai through- 
out the greater part of geological time the rail IT- climate * 
much more uniform than at present. It has been claimed ' that 
the zonal climates now existing, were scarcely recognizable in the 
earlier geological periods, but are first clearly defined in the 
Pliocene — the era just preceding the succession of glaciations 
constituting the great ice age. 

While the great fluctuations in the distribution of land and 
water areas during the ages undoubtedly exercised a very gre 
influence on the prevailing climate, it is difficult to see how under 
any conditions, conceivable at the present day, it would be possible 
for such trees as magnolias, figs, walnuts and sequoias to live in 
the latitude of Spitzbergen and Greenland as they undoubtedly 
did in the Eocene. 

It is true that in regions with an insular climate, such as smith- 
eastern Alaska and New Zealand there is a luxuriant vegetation 
in relatively high latitudes, due to heavy rain-fall and absence <»f 
severe cold; but such conditions are hardly conceivable at the 
present day in regions less than ten degrees from t he pole. 

Especially during the Carboniferous was the flora of the earth 
extremely uniform. "We find practically identical assembly 
of plants wide spread over western Europe, central and i stern 
Asia, South Africa, eastern North America and probably southern 
South America." 2 

Even more widely spread floras occur in the Jurassic, which are 
known to range from Franz Josef Land, 82° N.. to I Iraham I.ai d. 
63° S., and to extend practically completely round the world. 

From the nature of the plants of these periods, one may conclude 

that the climate was a mild— perhaps subtropical our. and that 
there was very heavy precipitation. Such a climate seems to 
have prevailed during much of geologic time. 

There were, however, periods of lower temperatures, indi 
bv evidences of extensive glaciation, especially during I he Permian. 
At that period, there are abundant evidences of extensive glacia- 

« Knowlton, F. H., " Evolution of < Geologic < Jlimatee/' Bull. Q 
Vol. XXX, pp. 499-566, 1919. 
2 Knowlton, loc. cit., p. 51-'. 



4 OUTLINE OF PLANT GEOGRAPHY 

tion, especially in the southern hemisphere, even within the 
tropics. 

Various theories to account for the climatic conditions in 
geologic time have been propounded. A recent one * elaborated 
at some length assumes that prior to the Pleistocene, the climate 
of the earth was controlled by its own heat, the effects of solar 
radiation being excluded by a thick cloud envelope. Under such 
conditions there would be no zonal climates, but changes in climate 
would be due, mainly, to the relative distribution of land and 
water. The temperature of the oceans was much higher and more 
uniform than at present, and glaciation might occur anywhere, 
provided there was a continental area of sufficient extent to permit 
a loss of heat by radiation enough to reach the freezing point. 

The presence of glaciers by no means implies an extremely 
cold climate. Today one may see growing in close proximity 
to extensive glaciers luxuriant forests, as in southern Alaska, or 
even plants of tropical origin, as in southern New Zealand, where 
in lat. 44°, tree-ferns, and trees and shrubs of Malayan affinities 
may be found close to the great Franz Josef glaciers which descend 
to less than 1000 feet above the sea. 

The extension of many tropical genera into the temperate parts 
of New Zealand is very remarkable, and this fact makes one 
cautious about concluding that the presence of tropical genera 
in a fossil state necessarily implies a tropical, or even sub-tropical 
climate. 

Succession of Plants in Geological Time 

The first organisms to appear upon the earth were doubtless 
extremely simple in structure. Of living forms, the bacteria may 
offer some suggestions as to the character of the first living things. 
That bacteria existed at an extremely remote period is certain, 
as their activities are essential for the existence of all other or- 
ganisms. Their extremely small size, however, makes a positive 
demonstration of their presence in a fossil state, a difficult matter. 
It is interesting to find, however, that the earliest known positive 
remains of plants belong to the blue-green algae, forms which 
probably are related to bacteria. 2 Wolcott has described from 

1 Manson, M., The Evolution of Climates, Baltimore, 1922. 

2 Knowlton, F. H., loc cit., p. 506. 



INTRODUCTION 

pre-Cambrian rocks of Western America a Dumber of forma of 
these organisms which are supposed to be responsible for extend 

limestone deposits of that region. 

Most of the lower plants, however, like the algae, or Bea-weeds, 
have very delicate tissues extremely perishable, and capable of 
being preserved in a fossil state, only under the mosi exceptional 
conditions; so it is not remarkable that the geological history of 
these plants is very incomplete, and many of the records of im- 
pressions of algae are, to say the least, doubtful. 

There is good reason to believe that many of the simplest of 
the living algae are but little changed from their ancient relath 
of the early geologic time. We are told that the ancient Beas 
were fresh-water, and the ancestors of the living plants presumably 
originated in a fresh-water environment. As conditions in fresh 
water have not greatly changed, it is reasonable to suppose that 
as in the case of such simple animals as Amoeba and many flagel- 
lates, many of these primordial plants have come down to modern 
times with little change. 

From these primitive green algae it is believed the higher green 
plants, including the flowering plants, have been derived. 

While most of the green algae have left no recognizable fossil 
remains, there are some which secrete calcareous incrustation-. 
which have enabled the geologist to recognize these in a fossil 
state. The oldest of these go back to the Silurian. Two types 
especially, Siphoneae now mostly tropical marine algae, and the 
Charales (Stoneworts), fresh water forms, occur without question 
in a fossil condition. 

Two very important classes of algae, the red and brown sea- 
weeds, are probably of more recent origin than the green algae. 
They are essentially salt-water plants, and it may be assumed that 
their main characteristics have been developed with the increasing 
salinity of the oceans in the later geologic time. 

Of the brown algae, the remains are very doubtful in mosi 
cases, although many fossils have been attributed to this class. 

Among the red algae, there are a good many the >ral- 
lines"— which secrete lime in quantity, and play a very important 
role as reef-builders. Corallines are found abundantly in a fossil 
condition, the oldest fossils attributed to this group occurring in the 
Silurian; but they are mostly from much more recent formations. 



6 OUTLINE OF PLANT GEOGRAPHY 

We may assume that the ancestors of the existing vegetation 
of the earth were very simple fresh-water algae. 

In course of time there were manifested two divergent lines of 
evolution in the plant kingdom, connected directly with a change 
in environment. 

As the seas became more and more saline, we may suppose that 
certain of the primitive algae adapted themselves to the denser 
salt water, while others confined themselves to the fresh water 
streams and lakes. At the present day two classes of algae, the 
brown and the red, are preeminently the marine plant types, 
aside from certain minute floating forms like the diatoms. Ex- 
cept for a relative small number of green algae, and a few flowering 
plants like the eel-grass, etc., the marine coastal flora is mainly 
composed of the red and brown sea-weeds. 

The largest class of algae is that of the diatoms, unicellular 
plants of which over 10,000 species are known. Owing to their 
characteristic flinty shells, they are found in a fossil state in enor- 
mous quantities. In spite of their simple cell-structure, which 
would imply that they are primitive forms, the fossil record in- 
dicates that they are among the most recent of plant types, no 
certain remains being known much below the Cretaceous. As 
they are especially abundant at present in cold waters, being 
particularly numerous in the arctic and antarctic seas, it is 
possible that they are forms which are especially fitted to cold- 
water conditions and owe their great development to the refrigera- 
tion of the ocean, and the general cooling of the earth's climate 
which developed during the Tertiary, culminating in the Pleisto- 
cene glaciation. 

Much more significant was the abandonment of the primeval 
aquatic habitat for life on land. This was undoubtedly the most 
momentous event in the history of the vegetable kingdom. The 
much greater range of conditions on land, involving questions of 
water storage and the development of mechanical or supporting 
tissues, as well as adaptation to greater range of temperature 
and other conditions, at once open up a practically unlimited field 
for the operation of natural selection, and marked the beginning 
of the reign of land plants which henceforth were to dominate 
the vegetation of the world. 

Just when the first algae left the water and took up their abode 



INTRODUCTION 7 

upon the muddy bank of some ancient pond or marsh, we can 
never know, as we can hardly hope to find recognizable remains 
of the extremely delicate and perishable organisms of the very 
ancient formations when land life first began. 

Fungi 

In addition to the algae, which are characterized by the pi 
ence of the characteristic green pigment, chlorophyll, there is a 
vast assemblage of plants, structurally of about the same degree of 
development as the algae, and perhaps derived from them. Th< 
plants, the fungi, are destitute of chlorophyll, and hence depend- 
ent on organic substances for food, and at the present time play 
a very important role in the land-vegetation of the woild. 

While there is abundant evidence that fungi existed in the 
earlier geological formations, the record is too incomplete to 
throw much light on their early history. The best known fossils 
are parasitic forms which are found in the tissues of higher plants, 
and it is evident that as at present fungi were the cause of serious 
plant diseases. 

The First Land Plants 

The first unmistakable land plants are first met with in the 
early Devonian formations, but these have already attained a 
structure which implies a long series of intermediate forms be- 
tween them and the ancestral algae. 

The Bryophytes (mosses and liverworts), which are the low 
of the existing land plants, have apparently left few recognizable 
traces in the ancient rocks. There is every reason to believe that 
these have existed for a period antedating the first known remaina 
of land plants, but their delicate tissues are extremely perishable 
and positive evidence is not at present forthcoming. These plants 
have been rather neglected by the students of fossil plants, and 
possibly a more intensive search for their remains may throw light 
upon their early history. 1 

The early Devonian land plants belonged bo a peculiar group 
of vascular plants, i. e., plants with woody conducting tissues— 

1 A paper by Mr. J. Walton, in the Annuls of Botany, July, L926, describe! 
liverworts from shales belonging to the Middle Coai-Meaflure Age, from Shropal 

in England. 



8 OUTLINE OF PLANT GEOGRAPHY 

sometimes separated as a distinct class — (Psilophyta). The 
oldest and simplest of these, the Rhyniaceae, show some very in- 
teresting resemblances to certain existing bryophytes, and support 
the theory that the vascular plants have come from some such 
bryophytic ancestors. 

The later Devonian formations show the beginnings of the 
different classes of ferns, horsetails and club-mosses, which 
constitute the Pteridophytes of the present day; bub there were 
also found in the latest Devonian certain types of seed-bearing 
plants as well, the Cordaitales, which, however, completely dis- 
appear before the end of the Palaeozoic. 

The various plant types of the late Devonian continue into the 
Carboniferous where they are supplemented by a great assembly 
of other related forms which have been preserved in a very perfect 
state in immense numbers, so that we can make a pretty accurate 
estimate of the vegetation of the great coal period. 

This flora during much of the Carboniferous was practically 
world wide in its distribution, and indicates a mild excessively 
humid climate, such as now exists in the mountain rain-forests 
of the tropics, and in some temperate regions like parts of New 
Zealand, where pteridophytes play a very important role in the 
vegetation. 

Ferns, horsetails and club-mosses abounded, the two latter 
classes having genera which attained tree-like dimensions and 
were much better developed than their degenerate modern repre- 
sentatives. Among tree-ferns and club-mosses were seed bearing 
types, the Cordaitales, beginning at the end of the Devonian, 
which flourished in the Carboniferous. All of these Palaeozoic 
seed -plants disappear before the next great geological epoch — 
the Mesozoic — and their place is taken by forms related to exist- 
ing ones and which first appear in the Permian. 

The latter part of the Carboniferous and the succeeding Permian 
era show evidences of a decided cooling off, extensive glaciers 
existing, especially in the southern hemisphere. At this time, 
the land-masses of the southern hemisphere appear to have been 
in more or less intimate connection, and this "Gondwana Land," 
was quite separate from the northern land masses, and in it was 
developed a peculiar flora " Glossopteris flora" which was supposed 
to be a cold-climate one, and supplanted the earlier Carboniferous 



INTRODUCTION 9 

floras which survived for some time later in the northern hemi- 
sphere. This separation of a northern and southern flora ifi signifi- 
cant, as probably something analogous took place a1 a later period, 
resulting in the marked differences now existing between the 
temperate floras of the northern and southern hemisphere 

With the opening of the Mesozoic seed-bearing plants in- 
creased in numbers and importance, but were all "gymnospenrj 
i. e., forms with exposed seeds, like those of the living coniferous 
trees. The latter were represented by forms allied to the Arau- 
carias and Kauri pines of the southern hemisphere, and the cycads 
and Ginkgo of the present day. The cycads are palm-like woody 
plants, with less than 100 species at present, inhabitants of tin- 
tropics and warm temperate regions. The only existing repre- 
sentatives in our territory, are two small species of Zamia in 
southern Florida. 

Ginkgo biloba, the curious "maiden-hair tree," not infrequently 
seen in cultivation, is the sole survivor of a large order of tn 
which flourished in the early Mesozoic. The living species has 
been found wild in western China, but has been cultivate. 1 in 
China and Japan for a very long time. 

The cycads reached their culmination in the middle of its 
Mesozoic (Jurassic) when they were a predominant feature 1 of the 
vegetation. The most specialized forms had flowers suggesting 
those of some of the higher flowering plants, and it has even been 
thought that these (Angiosperms) may have originated from 
some of the Jurassic Cycadophytes. In the Jurassic are found 
also the beginning of the modern coniferous genera, pine-, cy- 
presses, cedars, etc., and the first sequoias are probably of about 
the same age. With the establishment of the modern conife 
the cycads become much less important and only a few of the !• 
specialized genera have survived to the present day. 

The last period of the Mesozoic, the Cretaceous, is notable ai 
period of extraordinary development of new life-forms, both plant 
and animal. The vegetation indicates a moisi warm uniform 
climate, due, perhaps, in part to extensive invasions of the land 
by the oceans. 

In the Cretaceous are found for the fust time unmistakable 
remains of angiosperms, the modern type of seed-bearing plai 
These are first encountered in the lower Cretaceous, where they 



10 OUTLINE OF PLANT GEOGRAPHY 

are associated with a flora composed for the most part of ferns, 
cycads and conifers. The earliest fossils supposed to be angio- 
sperms are of somwehat doubtful nature, and their relationships 
are obscure; but even in the lower Cretaceous there are found 
remains of such modern trees as oaks and willows, and in the 
upper Cretaceous a great many existing genera are met with. 
By this time most of the existing genera of conifers — pines, firs, 
cedars, etc. — were well established, and often much more wide- 
spread than at present. And such familiar angiospermous trees 
as oaks, poplars, sycamores, sweet gum (Liquidambar), magnolias, 
laurels and many others were found in many parts of the world. 

During much of the Cretaceous there are evidences of extensive 
invasions of the land by the ocean, so that the distribution of the 
principal land masses was very different from that now existing. 

In North America the Gulf of Mexico was connected with the 
Arctic Ocean, completely separating the western portion of this 
continent from the Atlantic area. Much of South America was 
submerged, and extensive invasions of the sea took place in 
Europe and Asia, and in Australia there are indications that an 
ancient West Australian continent was separated from the north- 
eastern part, then probably united with New Guinea. 

The end of the Cretaceous was a period of mountain building, 
especially in western America, and with the land elevation, 
North America assumed much of its present configuration. 

In Europe and Asia the Tertiary was a period of mountain 
building, and the present conformation was attained at. a later 
period than in America. 

While the northern continents had assumed very much their 
existing condition before the end of the Tertiary, there were at 
various periods direct connections between Eurasia and North 
America. Remains of the land bridge still exist between Alaska 
and Kamtchatka, and the mainland of Siberia is separated from 
Alaska only by the narrow Behring's Strait. 

The connections between Europe and northeastern America are 
much less obvious, but there is ample evidence that such connec- 
tions did occur during the Tertiary. 

With these changes there is evidence from the fossil plants that 
there was a general lowering of temperature during the Tertiary 
in the northern hemisphere. During the earlier period (Eocene, 



[NTRODUCTION 11 

Miocene) the climate of Europe was evidently sub-tropical, or hi 
any rate mild enough for palms and other t ropica] types to flourish. 
In the Pliocene these give way to trees of northern types, oak 
beeches, etc. The marine fossils indicate that the ocean was grow- 
ing colder also. 

The Pliocene floras of the northern hemisphere are well known. 
and consist of genera which still exist, but with a very different 
distribution from that of Tertiary times. Many of th< aera, 

and probably some species, have survived to the present. Thi 
are best represented at present by the forests of Atlantic North 
America, and those of the Himalayan regions, China and Japan 

in Asia. 

With the pines, firs, oaks, maples, willows and poplars now 
found throughout the north temperate zone, were mingled other 
genera, at present more restricted in their range. Such are the 
giant sequoias of California, the bald cypress (Taxodium) of the 
Gulf States, hickories, walnuts, magnolias, tulip trees, sassafras 

and others. 

The explanation of the present range of these trees is to be 
sought in changes of climate, and especially the changes resulting 
from the series of refrigerations constituting the great Pleistocenr 

glaciation. 

The effects of the extensive glaciation in the northern hem- 
isphere upon the distribution of both plants and animals w 
far-reaching, and have been the subject of many investigations. 

In the old world, especially in Europe, the extinction of many 
types, existing in the Pliocene, was brought about. Such tn 
as magnolias, hickories, sweet gum and others, still existing in 
America and eastern Asia, were completely extinguished in 
Europe owing to the complete glaciation north of the Alp-. 1 heir 
former existence is evident from abundant fossil remains in the 

Tertiary rocks. 

In eastern America the glaciation extended only to about 
latitude 40° and many of these trees were able to retreat south- 
ward, later following the northward recession of the melting I 
Such characteristic Tertiary trees as the tulip-tree (Iiriodend* 
sweet gum (Liquidambar), sassafras, walnuts, hickories and oth< 
still flourish in the Atlantic states and in parts of ( foina and Japan 
and the Himalayas, but have quite disappeared Iron, Europe, 



12 OUTLINE OF PLANT GEOGRAPHY 

where they formerly lived — as their retreat was cut off by the 
mountain ranges to the south. 

It is clear that the climate of the middle Tertiary was decidedly 
warmer than at present in the northern hemisphere, as most of 
the characteristic trees flourished far north of their present range, 
and there was a practically uniform circumpolar vegetation, as 
there is at present, but made up of elements requiring a much 
warmer climate than suffices for present arctic and sub-arctic 
vegetation. 

Within the United States there seems to have been a sorting 
out of the Tertiary types at the time of the glacial advance. It 
is likely that at this time the climatic conditions in the northern 
states were not very different from those now prevailing, i. e., the 
Pacific Slope was a region of dry summers and mild wet winters; 
the Atlantic of hot humid summers and severe winters. Between 
the two regions lay the semi-arid plains between the Mississippi 
and the Rocky Mountains, a region unsuited, for the most part, 
for tree growth. As the vegetation retreated southward, before 
the advancing glaciers, this central area acted as a barrier to 
further advance, and formed a wedge on either side of which there 
was a migration toward the more favorable coastal regions. In 
this migration the species adapted to the dryer summer conditions 
of the West Coast have survived in the Pacific region, while 
those requiring more humidity now constitute the bulk of the 
Atlantic forest. Thus at present we find a preponderance of ever- 
green trees, especially conifers in the Pacific forests, while the 
Atlantic forest is largely composed of deciduous species. 

As the glaciers retreated northward the arctic and sub-arctic 
plants followed closely and established themselves in their present 
circumpolar area. This area, once occupied by the warm temperate 
Tertiary flora, is now much too cold to support most of these, many 
of which, however, survive in the warm temperate regions of 
eastern Asia and North America. 

In some cases, arctic species, instead of following the receding 
ice northward, attained the same climatic conditions by ascending 
the mountains until they reached an elevation where the tem- 
perature was favorable to their growth, and as the lowland climate 
became warmer, they moved to still higher elevations, so that 
these arctic refugees are now found stranded on the summits of 



INTRODUCTION 13 

mountains far away from their kin in the lowlands of the arctic 
and sub-arctic regions. 

The presence of boreal species in high mountains in lower 
latitudes, is a familiar feature of plant distribution in Europe and 
the United States. A number of species for example, occur at the 
summit of the White Mountains which are found at sea-level in 
Labrador and Greenland, and the alpine summits of the Rocky 
Mountains and Sierra Nevada have species which inhabit the 
lowlands of Alaska and arctic British America. 

In the northern hemisphere, therefore, it was the extensive 
Pleistocene glaciation which must be considered the greatest 
single factor in the establishment of the temperate floras of the 
present day. 

Our knowledge of the conditions in the southern hemisphere 
during the Tertiary is very incomplete, and the origin of the 
modern south temperate floras is very uncertain. 

Unlike the arctic regions, the antarctic continent is separated 
from the temperate zone by a broad ocean belt, so that the south 
temperate lands are completely isolated, and the relationships 
of the floras of South Africa, South America and Australasia, are 
much less intimate than those of Eurasia and temperate North 
America. 

Nevertheless there is sufficient resemblance, especially between 
sub-antarctic South America and Australasia, to warrant the 
assumption of some former land connection, probably via some 
northern extension of the present antarctic continent. 

The latter, at present, is practically destitute of vegetation, 
but there is sufficient fossil evidence, to show that within a few 
degrees of the pole there formerly flourished plants which must 
have needed a temperate climate, at least, for their existence, and 
fossils of a later date from Seymour Island, south of Patagonia, 
show remains of species closely related to some of those now found 
in New Zealand. 

Our knowledge of these antarctic fossils is too meagre to permit 
any positive conclusions as to the character of the ancient antarctic 
flora as a whole, or to decide whether there was a continuous 
circumpolar Tertiary flora as in the northern hemisphere. Should 
such be the case, it would explain the occurrence of the same 
antarctic types in Patagonia and Australasia, which might be 



14 OUTLINE OF PLANT GEOGRAPHY 

relics of an ancient wide-spread Tertiary flora derived from the 
antarctic continent. 

In South Africa and South America there is direct communica- 
tion with the lands to the north and a certain intermingling of 
northern and southern types; but Australia and New Zealand 
are completely isolated at present, and such former land connec- 
tions to the north, which there is strong reason to believe once 
existed, have completely disappeared. 

The vegetation of northeastern Australia (Queensland) and 
New Zealand, is evidently related to that of the Malayan Archi- 
pelago, and there is abundant evidence of former connections 
with the tropical regions to the north. 

Western Australia was apparently completely separated from 
Queensland, in the Cretaceous, and it has been thought that in 
the ancient western continent the present extremely specialized 
Australian flora had its origin. 

After the union of western and eastern Australia, and the 
establishment of the extensive land tracts which now occupy most 
of the great continent, it may be surmised that these western 
plants invaded the territory to the east, encroaching upon the 
Malayan rainforest flora, which has now become restricted to 
a relatively narrow strip near the east coast where rich soils and 
abundant rainfall have permitted it to survive. 

In New Zealand, although the climate is a temperate one, the 
Malayan element is far more important than in Australia owing 
to the abundant and well distributed rainfall over most of the 
country. 

There is another very important element in the New Zealand 
flora, especially in the south where one meets trees, shrubs and 
herbs whose nearest relatives are in the colder parts of South 
America: Patagonia and Tierra del Fuego. Some of these have 
also reached southeastern Australia and Tasmania. 

At present, New Zealand is separated from South America 
by more than 90° of longitude and it is quite inconceivable that 
these plants have been transported over such a vast expanse of 

ocean. 

During the Permian era, it has been held by many geologists, 
that the present isolated southern land masses — i. e., South Africa, 
South America, part of India, and Australia, — were united in a 



INTRODUCTION Lfi 

vast continent, "Gondwana Land/' which also included a pari 
of the antarctic continent. How far these connections wei 
maintained during the Mesozoic and Tertiary seems to be very 
uncertain; but some such connections would seem to be nec< - 
sary to account for the present distribution of these Bub-antarctic 
plants. 

Existing Factors in Distribution 

Among the factors of prime importance in the distribution of 
the present floras of the earth, perhaps the first is the relation of 
the great continental masses to each other, and to the great bodies 

of water surrounding them. 

The proximity of Eurasia and North America, especially in 
the North Pacific region, is reflected in the evident relationships 
of the northern floras throughout the northern hemisphere, while 
in the southern hemisphere the plants of the different continents 
are much less closely related, as might be expected from the isola- 
tion of the principal land-masses. 

The oceans are efficient barriers to the migration of all but a 
small number of plants, and high mountain ranges form obstacles 
to the passage of plants, as do extensive arid regions such as occur 
in the centre of most of the continents. While mountain chains 
act as barriers they also may serve as highways, as for instance 
in the Sierra Nevada and Rocky Mountains where many arctic 
and sub-arctic species have migrated southward far beyond their 

original homes. 

Many plants, however, have developed special contrivani 
for distributing their seeds and spores, which enable them to 
spread rapidly, and overcome to some degree the barriers of Sea 
and mountain. 

Many of the lower plants, including certain ferns, produce many 
very light spores, which retain their vitality for long periods and 
may be carried great distances by air-currents. Thus ferns are 
among the earliest plants to invade oceanic islands, where the 
original vegetation has been destroyed by volcanic action or other- 
wise. 

The winged fruits and seeds of thistles, dandelions, milkweed, 
and many other similar plants may be borne by the wind very far 
from their origin and enable these weeds to spread with great 



16 OUTLINE OF PLANT GEOGRAPHY 

rapidity, and the quickness with which they take possession of 
a new country when accidentally introduced by man is sufficient 
proof of the efficiency of their methods of seed distribution. 

The winged fruits of such trees as the maple, ash and elm, are 
also adapted to transportation by air currents, but are too heavy 
to be carried long distances, except under particularly favorable 
circumstances. 

Water transport is much less common, but nevertheless rivers, 
especially in flood, may transport masses of vegetation or separate 
fruits and seeds far from their point of origin. 

Ocean currents also play a not unimportant role in the distribu- 
tion of seeds and fruits, but this form of transportation is confined 
mainly to a relatively small number of maritime species. In the 
tropics, especially, there are a good many species, like the coco- 
nut, screw-pines, Casuarina, which usually live close to the sea- 
shore. These strand plants often have fruits which are provided 
with buoyant and water-proof envelopes which enable them to 
float in the salt water for a long time, without injury; and such 
fruits may be drifted for a very long distance before they are 
thrown on shore, when they quickly germinate. The coconut 
is the best known example, but there are others like the screw- 
pines, and certain leguminous species growing on the shore which 
have fruits adapted to water transport. In the eastern tropics, 
species of Barringtonia, a handsome tree belonging to the family 
Lecythidaceae has conspicuous fruits which are often seen floating 

in the sea. 

Perhaps of even greater importance than air currents for trans- 
porting seeds, is the role played by birds and mammals in plant 
distribution. The many forms of adhesive fruits and seeds, like 
"burs," "stick-seed," "cockle-bur," etc; the bearded grains of 
many grasses, which adhere so tenaciously to the coats of animals — 
or the trousers of men— are practical demonstrations of Nature's 
contrivances for the dissemination of her plant children. 

Occasionally there is a sticky matter by which fruits adhere, 
as in the mistletoe, whose glutinous berries stick to the feet or 

plumage of birds. 

Birds undoubtedly take first place as agents of plant distribu- 
tion, owing to their rapid flight. Especially in the case of plants 
with small edible fruits, like many kinds of berries, birds are the 



INTRODUCTION 17 

most important agents in spreading them. Robins, for example, 
devour great quantities of pulpy fruits like hawthorn berries, 
grapes, strawberries, etc. The seeds pass through the body un- 
digested, and indeed in many cases, better fitted for germina- 
tion than before. Owing to their powers of flight, the seeds may 
be discharged from the body many miles away from the parent 
plant, and undoubtedly such fruit-eating birds have had much 
to do with the rapid spread of many species. 

Another way in which birds may be agents in distributing seeds 
and spores, is by means of mud in which seeds are imbedded. 
Adhering to the feet of migratory birds the mud, with its cargo 
of seeds, is thus carried long distances. 

Finally, man, involuntarily or otherwise, has been the cause of 
the migration of many plants over pretty much the whole earth. 1 

Man and the Plant World 

Man's very existence is bound up with that of plants — whether 
he is a naked savage maintaining a precarious existence by means 
of the fruits, grains and roots he may find growing wild, or a highly 
civilized white man, dependent on the grains, fruits and vegetables 
that he has brought under cultivation. 

Most of the staple food plants of civilized man are so changed 
by ages of cultivation that their origin is obscure; but some of 
them, like rice and sugar-cane, are evidently closely related to 
species still growing wild, and several species of wild bananas 
are known, some of which are probably the ancestors of the culti- 
vated varieties. So in northern countries, the common fruits, 
apples, pears, cherries, plums, strawberries, etc., are evidently the 
improved progeny of existing wild species. 

Wheat is supposed to have originated somewhere in Asia Minor, 
maize in Mexico, while wild potatoes of several species are common 
in parts of Chile and Peru. 

Having brought these plants under cultivation, man has carried 
them with him in his wanderings, and thus has spread over the 
whole earth. 

In addition to food plants, he had also developed many plants 
for their fibres, such as cotton, flax and hemp. 

1 A recent noteworthy book on plant distribution is by Dr. J. C. Willis, Age 
and Area; a Study in Plant Distribution and the Origin of Species, Cambridge, 1922, 



18 OUTLINE OF PLANT GEOGRAPHY 

Wherever man has settled, the original vegetation has been 
more or less profoundly altered. Primaeval forests once covered 
the sites of many a great city, and the sod of the prairies has been 
broken and given place to fields of corn and wheat, and the 
orchards and meadows of countless farms of the mid-west. 

In his earliest development primitive man only took from the 
forest such food as he might find — fruits, nuts or roots, thus 
doing no more to disturb the equilibrium of the plant association 
than would be done by the foraging of any other animal; but as 
soon as he developed the most rudimentary form of agriculture, 
or attempted to provide grazing for animals, tame or wild, he 
began a warfare with the vegetable kingdom which has continued 
with increasing energy down to the present time. 

Such primitive races of man are to be found today only in a few 
remote parts of the world. The Australian Blacks, and a few 
scanty remnants of primitive races in various tropical countries, 
still exist, but constitute only the merest fragment of mankind. 

At a very early period in his history, man practiced a primitive 
form of agriculture, and so soon as he had brought under cultiva- 
tion the cereals and other food plants, and had domesticated 
sheep and cattle, a new era was opened, and he was able to migrate 
far from his original home, carrying with him his cultivated food 
plants. 

Forests were cut down to afford ground for cultivation or pas- 
ture, and the native vegetation replaced by grain fields, orchards 
and vineyards. Indeed the ability to carry with him food in 
the form of grain and herds, alone made possible the great 
migrations of mankind, both in former times and today. 

With the facilities for transportation developed during the past 
century, migration has reached a stage absolutely unheard of in 
previous history, and the influx of millions of men into previously 
unoccupied regions is reflected in immense changes in the vegeta- 
tion of nearly all parts of the world — far greater than in any pre- 
vious period of the world's history. 

Forests have been swept away until the world is menaced with 
a timber famine, and their place has been taken by crops of all 
kinds, which are entirely alien to the country and completely 
alter the appearance of the landscape. This disturbance of the 
natural vegetation is not confined to the white settler alone, but 



INTRODUCTION 19 

the natives of many regions, as in Central Africa, and our own 
western plains materially reduced the extent of forest lands, by 
cutting and burning — partly to increase the extent of grass-lands 
for grazing of cattle or wild game. 

Unfortunately these primitive methods are not unknown in 
modern lands. The natives of our southern mountains still cut 
or girdle the trees to clear a corn patch, and in Australia and New 
Zealand sheep men burn and girdle trees to foster the growth 
of grass for grazing. 

Of course the destruction of forests for timber or for opening 
land for cultivation, is necessary; but unfortunately the process 
has been for the most part both wasteful and injurious to the 
land. Particularly destructive has been the reckless clearing of 
mountain slopes, and the resulting washing away of the soil with 
floods caused by the rapid run-off which the forest cover keeps 
in check. The land, denuded of its good soil, remains a barren 
waste, while the fertile soil is carried away by the swollen streams. 

The extraordinary and rapid change in the vegetation of a large 
area, due to man's activities is especially apparent in the United 
States, which a century ago was to a great extent untouched by 
man. The greater part of the country east of the Mississippi was 
covered with heavy virgin forest, and the great plains were in- 
habited only by scattered bands of roving Indians. Today in the 
eastern states the forests have given way to great cities, innumer- 
able towns and villages, and rich farm lands, where they are not 
dreary deserts, the results of thriftless lumbering and forest fires. 

Except for the native trees, the predominant vegetation at the 
present time is largely exotic. None of the staple food crops are 
indigenous, and the same is true for most of the common fruit-, 
although some of the latter — like grapes and berries of various 
kinds, — are of native origin. Even the weeds are mostly foreigners 
and have driven out the native woodland plants which have 
retreated before these hardy invaders. 

It is interesting to see, however, that given a chance, the native 
forest will often come back. All over the older settled regions of 
New England and the Middle States, the farm lands, deserted 
when the richer lands of the West were opened up, have already 
reverted to forest of the same type as that which originally covered 
them, while the prairies, which fifty years ago were unoccupied 



20 OUTLINE OF PLANT GEOGRAPHY 

save by the Indians and buffalo, are now the granaries of the 
nation. 

The deserts and mountains of this far west have as yet changed 
but little; but along the Pacific Coast the same changes are going 
on as in the Atlantic states a hundred years ago. 

In California the great valleys are covered with fields of wheat, 
barley and alfalfa; orchards and vineyards cover the foot-hills. 
The climate permits the growth of many products of the warmer 
zones, and oranges, olives, figs and lemons thrive, as well as the 
apples, pears, cherries and plums of the north. 

In these far western states, where a long dry summer prevails, 
irrigation plays an important role, and land naturally a desert 
or semi-arid, yields rich crops when water is available. 

Much land in southern California, now covered with luxuriant 
orange orchards, and adorned with innumerable beautiful trees 
and shrubs brought from distant countries, was desert before the 
days of irrigation. 

California, it is true, much more than a century ago, had in- 
troduced from Spain the orange, grape and olive, which flourished 
there long before it became a part of the United States. 

Besides the economic plants introduced by man he has imported 
from all over the world a host of ornamental species which adorn 
his gardens. Sometimes these escape from cultivation and become 
quite naturalized. In the cool moist coastal regions of northern 
California and Oregon one meets the showy broom and foxglove 
of Europe — and one sees these same plants in the similar climates 
of central Chile and New Zealand. In the latter country the 
sweet briar and blackberry, introduced from England as garden 
plants, have escaped and become extremely troublesome weeds. 

Most plants ranking as weeds, however, have been introduced 
accidentally, and wherever man has migrated, weeds have fol- 
lowed him, or been imported from divers sources. Many of the 
worst weeds owe their rapid dissemination to specially favorable 
adaptations for seed dispersal, like the wind-borne seeds of thistles 
and dandelions, or the hooks of burdocks and cockle bur, which 
stick to the coats of animals or men. 

Weed seeds may come in mingled with seed grain, or in the dirt 
adhering to animals or in the cargo of ships and railways. Rapid 
transit for mankind furnishes equally quick transport for these 



INTRODUCTION 21 

unwelcome immigrants, and one finds the common weeds of most 
localities very far away from their original homes. 

The thistles, burdocks, plantains, mulleins and other common 
weeds of the eastern United States are of European origin. In 
California, where the long summer is not favorable to these weed-, 
other species — black mustard, "filaree" (Erodium) bur clover, 
wild oats — have been introduced, probably from Spain, where 
the climate is much like that of California. 

Many of these introduced plants seem to grow with increased 
vigor in their new home, and may largely replace the native plants. 

In Australia some of the common weeds come from South 
Africa, Brazil, India, and one of the most troublesome, the prickly- 
pear cactus, is of American origin. The latter has become a very 
serious pest, occupying extensive tracts, especially in Queensland, 
and rendering them quite useless for agriculture or grazing. 

Man has also been responsible for the introduction of many 
animal pests — injurious insects, rats and mice, rabbits, etc., which 
may do great damage to vegetation, and greatly affect the flora 
of large areas. Destructive fungi have also been introduced by 
human agencies, and are responsible for extensive damage to 
crops, or native species. A recent example of the ravages of such 
a fungus, is seen in the complete extermination of the native chest- 
nut over a large part of the Atlantic states through the ravages 
of the fungus causing chestnut blight. It is supposed to have been 
introduced from China or Japan. The blister-rust of the white 
pine is another extremely injurious fungus which has come into 
the United States from Europe. 

While man has been responsible for the destruction of many 
plants, he must also be credited with having added many new 
forms to those already existing. The thousands of new varieties, 
the result of the labors of plant breeders, are witness to man's 
success as a creator of new plant types. 



CHAPTER II 
CLIMATIC ZONES 

Latitude, as might be expected, plays a very important role in 
plant-distribution, and for convenience we may recognize certain 
climatic zones between the poles and the equator, although, of 
course, these are by no means strictly limited by the parallels of 
latitude. These zones may be denominated: Boreal, North 
Temperate, Tropical, South Temperate and Austral. 

The distribution of land and water is very different in the north- 
ern and southern hemispheres, and this difference is strongly 
reflected in the climates. It is probable, however, that this 
disparity has not always been so marked. At present it is partic- 
ularly noticeable in the temperate zones. 

At the north, all of Europe, most of Asia, North Africa and the 
greater part of North America lie between latitudes 25° and 60°, 
and land extends without a break far beyond the Arctic Circle. 

In the southern hemisphere the only temperate area south of 
50° is the extreme southern point of South America, while the other 
temperate regions, New Zealand, Australia and South Africa all 
lie north of 50°, and except New Zealand scarcely extend beyond 
40°. To the south lies the unbroken Southern Ocean extending 
to the shores of the ice-bound Antarctic continent. 

Due to latitude, and the proximity of the ocean, the south 
temperate lands, for the most part, enjoy a very mild and equable 
climate. Never, except at high altitudes are they subjected to the 
severe winter cold that prevails at corresponding latitudes in most 
of the north temperate zone, whose climate is, in the main, 
decidedly continental in character. 

Melbourne, lat. 38° S. has a mean for the coldest month of 
48.5°, for the warmest 67.5°; Philadelphia 39°57' N. 32° for the 
coldest, 76° for the warmest; Wellington, New Zealand, 41° S., has 
a range only of 14.9° between the warmest and coldest months, 
while in Chicago, 41°53' N., it is 48°. 

The principal land-masses of the south temperate zone are 

22 



CLIMATIC ZONES 23 

widely separated by great ocean barriers, while at the north, the 
two great continental masses, Eurasia and North America, are 
almost joined by a chain of islands, evidently indicating an even 
more complete connection in not very remote geologic time. 

The great antarctic continent, completely isolated, and ice 
covered from the lofty mountains to the sea, is practically destitute 
of vegetation. 

Very different are the conditions in the arctic regions, where 
far beyond the arctic circle in Greenland, Spitzbergen and Alaska, 
there is an abundant flora which develops rapidly during the long 
days of the brief summer. 

Owing to the absence of any great barriers, we find that the 
vegetation of the higher latitudes in the northern hemisphere is 
relatively uniform, many species occurring throughout the range, 
so that the floras are very much alike in Scandinavia, Siberia and 
northern Canada. 

There is no true antarctic flora, and the austral flora is much 
less developed than the corresponding vegetation of the north. 

The austral or sub-antarctic flora is best developed in South 
America, but is also found in New Zealand and southern Australia 
It is quite absent from South Africa. 

The sub-arctic flora merges insensibly into that of the north 
temperate zone, which has much the same general character 
throughout Eurasia and North America. 

Conditions in the temperate regions of the southern hemisphere 
as already stated are very different and owing to the extreme 
isolation of South America, South Africa, and Australia, their 
floras are very different. It is true that there are certain corre- 
spondences pointing to former more intimate connection of the 
land-masses, than now exist; but the differences in the vegetation 
far outweigh the resemblances, and each of the three regions has 
an extremely individual flora, indicating a very long period of 
isolation. 

Comparing the floras of the northern and southern hemispheres, 
especially in the temperate regions, it is evident that certain 
families and genera are either confined to one or the other, or that 
they predominate to such an extent as to make it pretty certain 
that they originated there. Thus the oaks, maples, elms, birches, 
poplars, sycamores, are almost exclusively northern, and the same 



24 OUTLINE OF PLANT GEOGRAPHY 

is true of pines and firs. The rose family, buttercups and violets 
are mostly northern types, but may occur in the temperate regions 
of the south. It is thought that the latter may be immigrants from 
the north, which have become more or less changed by their 
residence in their new habitat. 

Probably of southern origin are many peculiar South American, 
South African and Australian types. Among these may be 
mentioned the peculiar southern conifers, the Kauri-pines 
(Agathis), Araucaria and Podocarpus. The Myrtle family, which 
has but few representatives in north temperate regions, is extraor- 
dinarily developed in Australia, where the genus Eucalyptus alone 
has over 200 species. Two extremely peculiar families, Proteaceae 
and Casuarinaceae, the former especially abundant in Australia 
and South Africa, the latter mainly Australian, are quite un- 
represented in the temperate regions of the north. 

It is true that some of these, like Araucaria and Podocarpus, 
once lived in the northern regions, from which they probably 
disappeared owing to climatic changes. 

It is possible that the peculiar northern and southern floras 
originated at a time when there was a more or less complete separa- 
tion of the mainland masses of the two hemispheres. During the 
Cretaceous, at which time many existing genera are first known, 
there were extensive invasions of the sea resulting in the sub- 
mersion of northern South America, North Africa and much of 
India, thus isolating the principal southern land-masses. About 
the same time, Western Australia was probably completely 
isolated, and it has been thought that many peculiar Australian 
types originated in this ancient Western Australian continent. 

Just what factors originally determined this segregation of the 
characteristic floras of the north and south temperate zones it 
would be difficult to say; but the subsequent differentiation is 
undoubtedly due in large part to the very different climatic 
conditions, and the much greater isolation of the southern land- 
masses. 

The north temperate floras for the most part are subject to a 
much more severe and variable climate, but readily adapt them- 
selves to the milder climates of the south temperate; and this may 
explain the presence of such northern types as buttercups and 
violets in New Zealand and Australia, while such Australian forms 



CLIMATIC ZOXES 25 

as Eucalyptus and Grcvillea (Proteaceae) could not adapt them- 
selves to the rigors of a northern winter, even should they succeed 
in reaching these regions. 1 

In both northern and southern hemispheres there is a more 
or less extensive mingling of warm temperate and tropical 
species near the limits of the zones, and sometimes extensive 
migrations from one zone to the other, due to climatic or topo- 
graphical reasons. Thus in New Zealand tropical genera may 
extend to 50°. 

Vegetation reaches its maximum development within the 
tropics, where optimum conditions of temperature and moisture 
prevail. Portions of the equatorial belt, such as the great islands 
of the Malay Archipelago, Java, Borneo, New Guinea, the rich 
lowlands of the Amazon and the West Coast of Africa, exhibit 
the most exuberant vegetation to be found anywhere. Uni- 
form high temperature, heavy rainfall and rich soils, combine 
to produce a maximum luxuriance of plant-growth, shown in 
dense jungles of giant trees of many species, loaded down with 
rampant creepers and epiphytic growths. Sometimes the shade 
is too dense for much undergrowth, but wherever light pene- 
trates, there quickly develops an inpenetrable thicket of rank 
vegetation, and the ground is carpeted with ferns and other 
shade-loving plants. 

It must be remembered, however, that not everywhere in 
the tropics does one encounter such luxuriance of growth. Re- 
gions of low rainfall, or poor soil, may consist of dreary arid 
grass-lands, or deserts of the most pronounced type, as in the 
Sahara and parts of Australia. 

On the other hand, in exceptional cases due to specially favor- 
able conditions of temperature and moisture, vegetation of 
decidedly tropical character may be found far beyond the actual 
tropics. This is particularly the case in parts of the southern 
hemisphere, where owing to unusually heavy rainfall, and absence 
of extreme cold, many tropical types have extended their range 
far beyond tropical latitudes, and the forests are very different 
from those in corresponding latitudes in the northern hemisphere. 

Unlike the temperate regions of the northern hemisphere, 

1 For a fuller discussion of this question see Wallace, A. \\\, Island Lif> \ pp. 
486-487. 



26 OUTLINE OF PLANT GEOGRAPHY 

the tropics of the old and new worlds are widely sundered by 
the great oceans, and as might be anticipated, the tropical veg- 
etation of the East and West is composed for the most part of 
very different elements. 

There are very few common species, and to a great extent, 
the genera and even families differ. This is evidently the result 
of a very long period of isolation combined with the more intense 
competition which must have developed under conditions so 
favorable to rapid growth and multiplication. 

While the superficial aspect of the equatorial forests of the 
old and new worlds is quite similar, nearer inspection will show 
a very great difference in the species of which they are composed. 

The Boreal Regions 

Under the name Boreal or Holarctic is included the whole 
of the regions lying between the Tropic of Cancer and the North 
Pole, but we may recognize three divisions, more or less well 
defined, the Arctic, Sub-arctic and North Temperate. 

As might be expected from the intimate connection between 
the northern continents their vegetation has much in common, 
so that many common trees of temperate Eurasia and America, 
for example, are obviously related. Pines and firs, oaks, beeches, 
maples, willows and poplars, are characteristic of the temperate 
regions of both continents, and the same is true of very many 
shrubs and herbaceous plants. 

This uniformity in the vegetation is especially marked in 
the arctic and sub-arctic zones, many species occurring through- 
out these regions, while in other cases, Eurasian species are 
represented in America by different, but closely related ones. 

Southward the differences become more and more pronounced, 
owing to isolation and different climatic conditions, as well as 
to an intrusion of tropical or subtropical types, which differ 
widely in the old and new worlds. 

The history of the origin and distribution of the boreal floras 
is revealed by a study of the abundant fossil plant remains in 
the Cretaceous and Tertiary rocks of both the eastern and western 
hemispheres. 

Originating, apparently, in the far north, there is found in 



CLIMATIC ZONES 27 

the early and middle Tertiary a wide-spread flora, which like 
the arctic and sub-arctic floras of today was very similar through- 
out, and occupied much the same range as the present arctic 
and sub-arctic vegetation. 

It is clear, however, from the plants composing this "Arcto- 
tertiary" flora, that the climate of the far north was very much 
milder than at present. Trees like magnolias, laurels, gums, and 
other denizens of warm temperate climates lived during the mid- 
dle Tertiary in Greenland and Spitsbergen where now only the 
hardiest of arctic plants can survive. 

The arcto-tertiary flora showed a division comparable to 
the arctic and sub-artic zones of the present. North of 75°, the 
plant remains seem to be strictly boreal types, like willows, 
poplars, oaks, etc., but in the southern zone are found remains 
of palms, laurels, myrtles, now characteristic of only the warmest 
parts of the temperate zones. 

With the increasing cold of the late Tertiary and Pleistocene, 
the arcto-tertiary flora which included the ancestors of most 
of the vegetation now occupying the north temperate regions, 
migrated southward, and came to occupy much lower latitudes. 

This retreat was greatly accelerated by the advancing glaciers 
of the ice-age, and in many regions, especially in Europe and 
northern Asia, many forms became quite extinct, but survived 
in the more favorable conditions of eastern Asia and America. 

With the amelioration of the climate in post-glacial time, 
there was a northward movement of vegetation following the 
retreat of the ice-sheet, and developing the modern arcto-glacial 
flora. 

The Arctic Zone 

The region surrounding the north pole is, of course, very 
incompletely explored; but where land occurs, it is completely 
ice-clad and probably quite destitute of any vegetation, except 
certain humble sea-weeds. 

However, an unexpectedly large number of flowering plants 
manage to exist within a few degrees of the pole, a considerable 
number of species being recorded as far north as 83°. 

From this region southward to where tree growth begins is 
the true arcto-glacial and tundra zone. Within this zone topo- 



28 OUTLINE OF PLANT GEOGRAPHY 

graphical conditions vary much in different regions. There are 
vast expanses of barren lowlands that have apparently not been 
subject to glaciation, especially in northern Siberia and parts 
of northern Alaska. Most of arctic Eurasia and America, how- 
ever, was covered by the great glaciers of the Ice Age, and in 
these regions the lowlands are covered with lakes, swamps and 
tundras — regions of frozen subsoils covered with a thick mat of 
mosses and lichens among which grasses, and low prostrate 
shrubs, like cranberries, rhododendrons, dwarf willows and 
birches may grow. In Greenland, Iceland, Scandinavia and 
Spitzbergen there are lofty mountains ice-covered to their base, 
making it impossible for any plants to grow, except on the mo- 
raines of the glaciers, or slopes which are free of snow for a brief 
period in summer. On such exposed places, there may be an 
unexpected luxuriance of vegetation, grasses and a number of 
beautiful flowers — poppies, saxifrages, buttercups and others 
which start into growth as soon as the snow melts. 

This northernmost zone of vegetation has a growing period of 
only two months, or a little more. Growth begins in June, cul- 
minates in July, and by the end of August freezing weather has 
again set in. 

Of course only a limited number of species can survive the 
excessive cold of these regions. Vegetation consists entirely of 
perennials, either herbaceous species with perennial underground 
roots or root-stocks which quickly send up their leaves and flowers 
during the brief period of sunshine and warmth; or else of low 
prostrate shrubs, sometimes evergreen, like the cranberries or 
Lapland rhododendrons, sometimes deciduous, as the dwarf wil- 
lows and birches. 

The degree of cold which some of these can endure is astonish- 
ing, since in some cases (as in northern Siberia), they are quite 
unprotected by snow, and must survive temperatures as low as 
-60°C. (-76°F.). 

The coldest regions in which there has been found a well-marked 
flora are in northern Siberia and Grinnell Land, northwest of Green- 
land. 1 The mean annual temperature of these regions is— 16°C. 
(4°F.). Even in midsummer the temperatures are very low. 
In Franz Josef Land, the July mean is only 2°C., and in Spitz- 

1 Drudc, Handbuch der Pflanzengeographie, pp. 352, 353. 



CLIMATIC ZONES 29 

bergen, 4°C. The period available for any plant growth is only 
about two months. Nevertheless there is an unexpectedly large 
number of species. In Spitzbergen 122 species of flowering plants 
are recorded, and in Greenland between 78° and 83° 88 species. 
At Cape Chelyuskin, the northermost point of continental Asia, 
23 species of flowering plants have been noted. 

The existing arcto-glacial flora was derived, presumably, from 
the much richer flora occupying the region to the south preceding 
the great ice-age. The limit of vegetation at the period of maxi- 
mum glaciation was probably far south of its present latitude, 
but as the glaciers retreated toward the pole, the hardier species 
moved northward to their present habitat. Such specific changes 
as have taken place, were comparatively of recent date, and the 
arctic flora as a whole is a recent one. 

The regions included in the arctic zone comprise the northern 
coasts of Eurasia and America with the adjacent islands, and the 
mountain masses immediately south. In northwest Europe, due 
to the invasion of the sea, and its tempering effect, the south- 
ern limits of the zone are pushed very far north, but in Russia and 
Siberia, and North America, arctic conditions prevail in much 
lower latitudes. 

The limits of the strictly arctic zone have been set between the 
northernmost limit of vegetation— about 83 °N.— regions with the 
July isotherm only 2°-4°C, and the regions to the south bounded 
by the 10°C. July isotherm. 

The general type of vegetation throughout the arctic regions 
is very similar and most of the species extend all round the world. 
Where peculiar species occur in any region, they are usually closely 
related to wide-spread ones, and may be assumed to be of relatively 
recent origin. Not infrequently species which are apparently 
recent immigrants from the south are met with; i. e., the arctic 
American Kalmia glauca. 

While the southern boundary of this zone may be said to corre- 
spond roughly with the arctic circle, it varies much in latitude, due 
to the differences in topography in various regions. 

Thus in the great continental areas like Siberia and Canada, 
it lies much further south than in Scandinavia, Iceland, Green- 
land and western Alaska, where the proximity of the ocean water 
greatly tempers the climate. 



30 



OUTLINE OF PLANT GEOGRAPHY 



In the strictly arctic regions, trees are completely wanting, 
and the shrubs reduced to prostrate mats, scarcely rising above the 
level of the ground. The bogs and tundra are largely occupied 
by dense growths of mosses and lichens, among which the grasses, 
sedges, and low shrubby growths are scattered. Where conditions 
are favorable there may be seen herbaceous plants, which from 
their perennial subterranean roots or tubers quickly start into 
growth in the summer and adorn the barren ground with their 
showy flowers. Among the characteristic flowers of the far north, 




Fig. 1. — Willow thickets on the upper Killik River, North Alaska. 

Photo., Dr. Philip S. Smith. 

are species of buttercups, anemones, primroses, cinquefoil (Po- 
tentilla), saxifrages, poppies (Pa-paver nudicaule), and whitlow 
grass (Draba) . 

Of the woody plants, dwarf willows and birches are characteris- 
tic, and several of the heath family; e. g., Rhododendron, Cassiope, 
Vaccinium, Empetrum. The only conifer of the arctic regions 
is a dwarf juniper. 

While a good many species are pretty strictly confined to the 
arctic zone, others like some species of cotton grass (Eriophorum) 
and some of the heath family, e. g., Rhododendron lapponicum, 
Cassiope tetragona, extend into the colder parts of the temperate 
zone. Other characteristic arctic species, like the pretty moun- 



CLIMATIC ZONES 31 

tain avens (Dry as octopetala) and the curious arctic Pedicularis 
(P. Groenlandica) , common species of the arctic lowlands, occur 
also as alpines in the Rocky Mountains and Sierra Nevada, while 
the much lower White Mountains have a few plants, e. g., Dia- 
pensia lapponica, natives of the far north. 

We may assume that the presence of these arctic species on the 
mountains to the south is to be explained by the assumption that 
they are remnants of the wide-spread arctic flora which at the 
period of maximum glaciation occupied the lowlands of these 
lower latitudes. With the retreat of the ice-sheet, and the increas- 
ing warmth of the lowlands, some of these arctic species managed 
to survive by ascending the mountains until conditions were 
reached adapted to their needs. 

Strictly arctic conditions are found in Europe only in parts of 
central and north Scandinavia, including parts of Lapland. 
In north Siberia, the most extreme arctic conditions prevail, 
and the lowest temperatures that have been recorded occur. 
In spite of this excessive cold, to which they are exposed with- 
out any snow-cover, a surprising number of species are able to 

survive. 

The north Siberian tundra region x has as its commonest 
formation the " Moss-tundra," whose principal constituents 
are mosses of the common genus Polytrichum. Among the mosses 
are various grasses and sedges, among them " cotton-grass " (Erio- 
phorum), common also in cold bogs much further south. Dryas, 
and the heath-like Cassiope tetragona are characteristic of the 
moss-tundra. 

Where there is water, true peat-bogs occur, peat mosses (Sphag- 
num) replacing the Polytrichum of the dry moss-tundra. On 
the slopes and precipices of the higher ground there is often 
a fairly abundant development of mats of grasses interspersed 
with bright flowers. Among the most notable, are species of 
Oxytropia, with bright yellow pea-flowers, blue Polemonium, 
various Saxifrages, and a showy avens (Geum). A bright blue 
forget-me-not (Erytrichium), is also characteristic of the Siberian 

arctic flora. 

All of these plants grow in low compact tufts, with small leaves 
exposing a minimum surface to evaporation. 

1 Drude, loc. cit., i>. 356. 



32 



OUTLINE OF PLANT GEOGRAPHY 



Much of the region is a desolate barren stony formation, whose 
sole vegetation is made up of various lichens growing on the broken 
rocks. 

The Behring Sea tundra district is only imperfectly known; 
but Kjellman l has described 221 species from this district. Of 
these 53 do not extend far westward, and comprise a number of 
peculiar species. Others are supposed to have come from the 
American side of Behring Sea, and some may have been immi- 
grants from the Baikal Mountains. Two genera also charac- 




Fig. 2. — Tundra, basin of Ikpikpuk River, North Alaska. 
Photo., Dr. Philip S. Smith. 



teristic of western America are Claytonia and Dodecatheon, the 
" shooting star" of our Pacific Coast. 

The western Alaska coast is much milder than corresponding 
latitudes on the Asiatic side, and the vegetation less pronouncedly 
arctic in character, although the northern part of Alaska shows 
climatic conditions comparable to those in Siberia. Spruces 
(Picea alba), alders and willows, extend to the polar circle, and form 
thickets of considerable extent, while the display of flowers is 
described as very remarkable. These comprise the usual arctic 
species, as well as species of spring beauty (Claytonia), forget- 

1 Drude, loc. cit., p. 356. 



CLIMATIC ZONES 33 

me-nots and anemones. A knot-weed (Polygonum) and dock 
(Rumex domestica), have fleshy roots which are used by the natives 
for food. 

The tundra region of Alaska and northern Canada, differs 
from the Siberian tundra in a much greater development of lichens, 
which take the place of the mosses which characterize the latter. 1 
Two species of lichens, Cetraria islandica and C. cucidlata, the 
so-called "reindeer moss," cover extensive tracts of land, and 
serve as the principal food of the herds of reindeer which abound 
in this region. With these lichens, as in the moss-tundra, are 
various prostrate shrubs, most of which are identical with those 
of the Siberian tundra, but one striking species, Kalmia glauca, 
is not found outside America. 

Meadows of coarse grasses are also found in places, and in favor- 
able localities a display of showy flowers, including a " shooting 
star' (Dodecatheon), one of the primrose family, especially 
developed in Pacific North America. 

The barren islands to the north have a very meagre flora, the 
greater number of species being grasses. 

Greenland and the adjacent regions have been more thoroughly 
studied than any other part of the arctic zone and belong rather 
to the Scandinavian region than to America. The southern part 
of this area is sub-arctic, and contains a good many species which 
hardly cross the arctic circle. One of these, the twin-flower, 
(Linnaea borealis), just reaches the arctic circle in places, and 
Drude 2 suggests that the northern range of this classical species, 
should be taken as the boundary between the arctic and sub- 
arctic zones. 

In the sub-arctic region, thickets of willows, and in the south, 
alders, are a prominent feature of the vegetation. There are 
extensive moors covered with dwarf shrubs, and barren rocky 
formations where little grows except lichens. Grassy moorlands 
and peat-bogs occupy the more level land between the mountains 
and the sea, and the sandy shores are mainly occupied by a grass, 
Elymus arenarius. 

Willow thickets occur as far north as 70°, and some of the 
herbaceous plants, e. g., Archangelica, especially in the southern 
portions, are of considerable size, and associated with hawkweed 

1 Drude, loc. tit., p. 357. »Ibid., p. 358. 



34 



OUTLINE OF PLANT GEOGRAPHY 



(Hieracium) , orchids, and other forms absent from the extreme 
arctic regions. 

In the high northern latitudes, elevation above sea-level, ap- 
parently makes little difference in the temperature, many plants 
growing at altitudes of 500-600 metres or even more. 

The severity of the arctic climate, and the very brief growing 
season, make any sort of agriculture impossible, and except for 




Fig. 3. — Tundra vegetation, basin of Colville River, North Alaska. 

Photo., Dr. Philip S. Smith. 

the grazing afforded reindeer and musk ox, and a few edible lichens, 
berries and roots, the plant-life of the arctic regions offers little 
help to man in supporting life. 



The Sub-arctic 

The northernmost extension of tree-growth, the timber-line, 
marks the southern limit of the strictly arctic vegetation. Be- 
tween the timber-line and the middle regions of the boreal area, 
lies a rathor indefinite zone, the sub-arctic. 

The number of tree species is limited, but they are often gre- 
garious, and may form forests of great extent. Coniferous forests 
are a marked feature of the sub-arctic, comprising firs, spruces, 
pines and larches, and low-growing junipers. Of deciduous trees, 



CLIMATIC ZOXI :s 



35 



birches, alders, willows and poplars characterize the more northern 
portions of the zone, while toward the south, oaks, beeches, horn- 
beams and chestnuts mark the beginning of more temperate con- 
ditions. 

Like the arctic zone, the vegetation of the sub-arctic is very 
much alike in both hemispheres, due in part to a large intermixture 
of arctic species, but also to the fact that most of the sub-arctic 




Fig. 4. — Northern limit of trees; white spruee, Unakserak River, lat. OS . 

Photo., Dr. Philip S. Smith. 

genera, and a good many species are common to Eurasia and 

America. 

Throughout the zone one encounters a very characteristic 
forest and bog flora composed of identical or closely related species, 
and this flora is met with far south of the sub-arctic in the moun- 
tains, and in the colder parts of the temperate zone. 

A notable feature of these northern latitudes is the abundance 
of club-mosses of the genus Lycopodium, most of the species 
occurring both in Eurasia and America. These are undoubtedly 
very old forms, and the same may be said of the horse-tails (Equi- 
setum), and a number of wide-spread species of sub-arctic ferns. 

Carpeting the floor of the northern evergreeD forests are several 
familiar and attractive plants of the wintergreeD family (Pyro- 
laceae). Several species of Pyrola, the dainty Bweel scented one- 



36 OUTLINE OF PLANT GEOGRAPHY 

flowered wintergreen (Moneses), and the " prince's pine" (Chim- 
aphila). Associated with them are several orchids, e. g., coral-root 
(Corallorrhiza) and rattlesnake plantain (Goodyera) . Much rarer 
is the beautiful Calypso borealis. In boggy places one may find 
another northern orchid, the tway-blade (Listera), and there are 
many other bog-plants common to the sub-arctic regions of the 
old and new worlds. Among these may be mentioned the sundews 
(Drosera) , buck-bean (Menyanthes) , and many grasses, sedges and 
rushes, as well as the species of Sphagnum and other mosses. 

In the northern part of the sub-arctic, the meadows and woods 
have many beautiful herbaceous plants. Some of these like He- 
patica and species of marsh marigold (Caltha palustris), cress 
(Cardamine), grass of Parnassus (Parnassia) dwarf cornel (Cornus 
suecica), and willow herb occur in northern Europe and in North 
America; more commonly the species of the old world and the 
new are distinct. 

While forests occupy much of the sub-arctic zone, there are 
extensive tracts of open country, like the prairies of western Can- 
ada and the steppes of Russia and Siberia. Where moisture is 
abundant, swamps, bogs and lakes abound. 

Within the sub-arctic zone may be included most of Scandinavia, 
Northern Russia, most of Siberia, Kamtchatka, Alaska and a 
large part of Canada and Labrador. 

Like the arctic zone, the sub-arctic reaches its maximum de- 
velopment in Siberia where it extends, in a broad belt, from the 
Urals to the Pacific. 1 

The climate throughout this vast region is one of excessively 
cold winters and moderately warm summers, but shows a con- 
siderable range in both temperature and moisture. Much of the 
region is an extension of the great northern plains through which 
the giant rivers make their way to the Arctic Ocean, very much 
as in the far north of America. 

To the west are the Urals, and south the great mountain ranges 
separating Siberia from Turkestan and Mongolia. 

The Siberian flora is a poor one, composed of strictly northern 
types, many of which are members of the arctic flora. The monot- 
onous forests of larch and spruce are interspersed with tundras 
and marsh lands, like those of the true arctic zone. 

? Drude, loc. cit., pp. 412-416. 



CLIMATIC ZONES 37 

The northernmost forest belt is made up of Larch with an inter- 
mixture of pines and birches, and some spruce. Open areas are 

covered with tundra vegetation of quite arctic aspect, with char- 
acteristic low evergreen shrubs — Ledum, Andromeda, Rhodo- 
dendron, and various others — among them the pretty twin-flower 
(Linnaea). Upright herbaceous plants with showy flowers — lark- 
spur, aconite, geranium, and others — are abundant, as they are 
elsewhere in the sub-arctic and alpine regions. 

Central Siberia, including the regions about Lake Baikal, is a 
country of lofty mountains, and typical Siberian flora mingles 
with that of the steppes of Turkestan and Mongolia. Owing to 
the greater moisture of much of this mountain region, as well as 
its proximity to the regions to the south, there is a more varied 
vegetation than elsewhere in Siberia. Vegetation extends high 
up in the mountains, plants having been collected at altitudes of 
3000 to 3200 metres. 

In western Siberia is a steppe region similar to that of southern 
Russia and the regions about the Caspian and Aral seas, but it 
is neither so dry nor so hot as in the latter regions. 

The soil varies, being sometimes a black loam, sometimes sandy 
clay, and in some places alkaline. 

This " birch-steppe" is so called from the groves of birches and 
alders which are scattered over it, somewhat like the " oak-open- 
ings" of the eastern prairies of the United States. These groves 
become more abundant and luxuriant in the cooler and moister 
climate of the north, while along the streams poplars and willows 
grow, and the dry steppe is replaced by prairies and bogs, which 
support a luxuriant growth of grasses and other herbaceous plants, 
including such showy flowers as Turk's-cup lilies, yellow day- 
lilies (Hemerocallis), anemones, and others. A giant umbellifer, 
Heracleum barbatum, is conspicuous, and much like the American 
" cow-parsnip " (B . lanatum). 

Eastward from the Altai region the climate is a very severe 
one, and the vegetation correspondingly scanty. 

The Kamtchatka peninsula forms a special province of the Sibe- 
rian flora, and because of the effect of the ocean, has a much milder 
climate and more abundant vegetation than the adjacent mainland. 

Especially interesting is the evident relationship of many species 
with those of Pacific North America. 



38 OUTLINE OF PLANT GEOGRAPHY 

There are in parts of Kamtchatka luxuriant forests and rich 
meadowlands and prairies, while elsewhere there are bog-lands, 
conditions much resembling those of coastal Alaska. The char- 
acteristic alders, birches and willows occur as well as larches and 
spruces. Among the latter 1 the great tide-land spruce {Picea 
Sitchensis) of western America, and a hemlock {Tsuga spf) are 
also suggestive of the Alaska forest. Lilies, willow-herb and other 
showy flowers are common, and the giant Umbelliferae, Heracleum 
and Angelica, are characteristic. 

At elevations of about 1000 feet is a scrub forest of dwarf pines 
(Pinus cembra) mixed with junipers and alders. Here also grow 
two fine rhododendrons, a genus especially developed in eastern 
Asia. 

Alaska 

The conditions in southwestern Alaska are not unlike those of 
northwestern Europe. Westerly winds, the numerous islands 
along the coast, and the deep fiords which indent it, combine to 
produce a climate of remarkable mildness for so high a latitude. 
This costal strip, moreover, is protected from the extremely severe 
climate of the interior by the lofty range of mountains parallel 
with the coast, the northern extension of the great Pacific Cordil- 
lera. 

The mild climate and heavy rainfall, as well as the connection 
with the Pacific Coast to the south, result in a luxuriance of vege- 
tation unequalled in any other part of the world in the same lati- 
tude, and can hardly be classed within the " sub-arctic" vegetation 
of other regions. 

As far north as 60° and west to Kadiak Island the coastal region 
of Alaska supports dense forests of large trees, and a luxuriant 
growth of shrubs and herbaceous plants in great variety, a great 
contrast to the Asiatic coast in corresponding latitudes. 

As the steamer makes its way through the channels between the 
innumerable islands of the Alaskan archipelago, they are seen to 
be clothed to the water's edge with a dense forest of tall evergreens, 
which extend to an elevation of 1000 feet or more. 

The prevailing species is the Sitka spruce, also said to occur in 
Kamtchatka. This is the largest of all spruces, although it does 

1 Drude, loc. cit., p. 417. 



CLIMATIC ZONES 



39 



not attain its maximum size in Alaska. A hemlock (Tsuga hete- 
rophylla) is also abundant, and somewhat less so a cedar (Chamae- 
cyparis nootkatensis) , both majestic forest trees. 

Along the shore one sees masses of giant kelps (Macrocystis, 
Nereocystis, and others). These enormous sea-weeds are a con- 
spicuous feature of the rocky shores of Pacific America. 

The deciduous trees, alders, willows, poplars and maples, are 
mainly restricted to the banks of streams, the maples suggesting 
the proximity of a more southern flora. 




Fig. 5. — Coastal forest, Southeast Alaska. 

The mossy carpet of the forest floor is adorned with many of 
the same plants that occur in Europe and Asia, e. g., Pyrola, 
Linnaea, dwarf cornel and various species of Lycopodium, but 
in addition there are many purely American species. 

Along the streams and the edge of the forest, as well as in the 
forest clearings is a jungle of shrubs forming impenetrable thickets. 
Among these are raspberries, elder, mountain ash, roses, spiraea, 
huckleberries and others decidedly suggestive of the temperate 
forests further south. 

A very characteristic member of this jungle is the " Devil's 



40 



OUTLINE OF PLANT GEOGRAPHY 



club" (Echinopanax horrida), whose great leaves and scarlet ber- 
ries are highly ornamental, but whose hideously spiny stems, are 
the terror of the woodsman, and amply justify the popular name. 
This plant, and a huge aroid {Lijsichitori), also occur in eastern 
Asia, and emphasize the relations between the floras of Kamt- 
chatka and Alaska. 

Thickets of a big horse-tail (Eqaisetum telmateia) also an old- 
world species, are common in low ground, and Sphagnum bogs, 




Fig. 6. — Interior of Alaskan coastal forest. At right, Sitka spruce; at left, 

"devil's club." 

with their characteristic flora, are a common feature of the 
region. 

The change in the vegetation as one leaves the rainy coastal 
belt and proceeds inland, is very marked. This is very clearly 
seen along the railway over the White Horse Pass between Skag- 
way and White Horse on the Yukon. 

As the train ascends from Skagway, following the canyon of 
the Skagway River, there is at first the luxuriant growth of trees 
and shrubs characteristic of this coastal region — spruces, cedars, 



CLIMATIC ZONES 41 

and some lodge-pole pine, mingled with alders, willows, mountain- 
ash and birch, and various shrubs — spiraea, raspberries, n> 
and others. A number of pretty flowers were noted — especially 
an unusual abundance of the dwarf cornel (Cornus Canadensis). 

The summit of the pass marks the timber-line, the spruces being 
only a few feet high, or forming prostrate mats. In early July, 
the creeping shoots of the dwarf arctic willow, were adorned with 
large and conspicuous catkins. 

From the summit, the pass gradually descends to the Lake 
region at the headwaters of the Yukon. 

This inland region, comprising parts of the Yukon Territory 
and Northern British Columbia, has a very different climate 
from that of the coast — relatively dry, and intensely cold in winter, 
so that the growing season is a very short one. Under such con- 
ditions it is rather surprising, therefore, to find along the Upper 
Yukon, a fairly abundant growth of good sized trees, mainly 
spruce, which furnishes lumber and fire-wood. Along the river, 
especially in the numerous islands, are groves of tall balsam 
poplars (Populus balsamifera), associated with thickets of alders 
and willows. Such forests may be seen as far north as Dawson 
(lat. 64°). Paper birches of fair size also occur in this region. 
The wide-spread lodge-pole pine (Pinus Murrayana), sometimes 
occurs in extensive stands along the Upper Yukon. 

Among the characteristic shrubs, perhaps the most beautiful 
is a rose (Rosa Nutkana), very common throughout the Yukon 
country. Other common shrubs are species of Spiraea, Ribes, 
Cornus and buffalo-berry (Shepherdia). In some places a service 
berry (Amelanchier sp.) was noted. In the dryer localities a low 
juniper (J. nana) and sage-brush (Artemisia frigida) may be seen. 

Many references have been made by visitors to these northern 
regions, to the profusion of showy flowers which adorn the brief 
summer. Some of these, like species of anemone and saxifrage, 
flower quickly after the snow melts; but the great majority belong 
to mid-summer, when they often occur in great numbers. 

A good many of these northern flowers, like the fireweed (Epilo- 
bium angustifolium), and such woodland flowers, as Linnaea, 
Pyrola, and the dwarf cornel, are common throughout much of 
the northern United States and Canada, and the same is true of 
such trees as the aspens, poplars, and some of the shrubs; but 



42 OUTLINE OF PLANT GEOGRAPHY 

many of the flowers belong entirely, or mainly to the arctic and 
sub-arctic zone. 

Among the less familiar flowers of the Yukon country may be 
mentioned a very beautiful " blue-valerian" (Polemonium) which 
is very abundant in places, as is a species of Mertensia (M. pa- 
niculato), with bell-shaped flowers of the most exquisite blue. The 
latter is especially common at Dawson. 

At White Horse, near the headwaters of the Yukon, in addi- 
tion to Polemonium and Mertensia, other common plants noted 
were species of Aster, golden-rod, gentian, avens (Geum), rattle- 
weed (Astragalus) vetch, and especially some very fine blue 
Pentstemons. 

The most striking display seen by the writer was at Lake Atlin, 
British Columbia. 

The rocky slopes along the shore of the lake were covered with 
a wonderful profusion of brilliant flowers. Blue ^Polemonium and 
Pentstemons, pink roses, pale yellow Geum, orange Cotyledon, 
white chickweed (Arenaria) covered the broken rocky ground 
with sheets of vivid color. 

In the moist woods, were a number of showy flowers, of which 
the most notable were a very handsome scarlet columbine 
(Aquilegia formosa) and a fine lupin (Lupinus Nutkanus). 

Bogs are common and for the most part harbor the usual north- 
ern bog plants. At Carcross, on boggy hillsides along the railway 
between Lake Bennett and White Horse, some interesting plants 
were noted. 

This was a moss-bog, but contained no Sphagnum. There 
were some interesting orchids, notably a very pretty white 
lady-slipper (Cypripedium sp.), and the round leaved orchis 
(Orchis rotundifolia) . The white mountain avens (Dryas sp.) 
still showed a few flowers, and the pretty violet-like flowers, the 
butter- wort (Pinguicula), were at their best. The white tufts 
of the cotton grass, and the exquisite starry flowers of the grass 
of Parnassus, which was very abundant, recalled similar bogs 
further south. 

In this neighborhood were noted some fine specimens of a large- 
flowered willow-herb (Epilobium) which was also very abundant 
in the river-bed at Skagway. 

Some of the coastal plants like the Sitka spruce follow the 



CLIMATIC ZONES 43 

canyons of the rivers into the mountains, but the forests of the 
Yukon country are very different from those of the coastal belt. 
The drier forest is made up mostly of white spruce (Picea Cana- 
densis), the northernmost Alaskan conifer, and associated with 
this are paper birch, balsam poplars and aspens. Two character- 
istic Rocky Mountain conifers reach Alaska — the lodge-pole 
pine (Pinus Murrayana) and a balsam fir (Abies lasiocarpa). 

The swampy ground is often covered with dreary forests of 
black spruce (P. Mariana). These spruce-bogs, known locally 
as " muskegs" are a characteristic feature of the Canadian north- 
west. The sub-soil is permanently frozen, and the surface soil 
in consequence is saturated. Travelling between the northern 
Canadian Rockies and the coast of British Columbia, one becomes 
sufficiently familiar with these dreary spruce bogs. 

As there are no high mountains east of the Rockies, the flora 
of the vast region between the northern Rocky Mountains and the 
Atlantic coast, including the basin of the Mackenzie River, the 
regions about Hudson Bay, and Labrador, is very much the same 
and quite similar to that of inland Alaska. 

The arctic tundras reach their southern limit in Labrador, whose 
flora has a good deal in common with Greenland, and at the south 
merges into the forest flora of Quebec and Ontario. 

In the west, the wooded area of the sub-arctic zone is confined 
to the more northern regions and passes gradually into the prairies 
of Saskatchewan, Alberta and Manitoba. Eastward the increas- 
ing precipitation permits forest growth throughout, and there is 
a gradual transition southward into the mixed forests of Quebec, 
Ontario, and the northern United States. 

Immediately east of the northern Rockies lies the great plain 
drained by the Mackenzie and its tributaries, a region of swamps, 
tundras and innumerable lakes, some like the Great Slave and 
Athabaska, of great size, passing at the south into the prairies 
of western Canada. 

Much of the northern district is forested, with white and black 
spruce, scrub pine (P. Banksiana), tamarack (Larix Americana), 
and balsam fir. Paper birch, balsam poplar and aspen are the 
common deciduous trees. Willows and alders border the streams. 
and other shrubs, honeysuckle, roses, currants, wild cherries, 
Viburnum, buffalo-berry (Shepherdia), snow-berries (Symphori- 



44 OUTLINE OF PLANT GEOGRAPHY 

carpus) dwarf junipers, and others form an undergrowth in the 
forest. 

The shallow water near the lake shores is a marsh, in which 
are bulrushes (Scirpus sp.) bur-reeds (Sparganium) cat-tails 
(Typha), various sedges and grasses, and the pond-weeds, water 
milfoil, and other common water-plants of northern regions. Yel- 
low water-lilies (Nuphar) also occur. 

The region between Lake Winnipeg and Hudson Bay is largely 
a region of swamps in which willows and tamaracks are the pre- 
vailing trees. East of Hudson Bay are the barren grounds of 
Labrador, a region of tundras, barren moorlands and rocky hills. 
At about 55°, tree-growth practically stops, but the southern part 
of Labrador has a forest of the same type as that of the Mackenzie 
region. 

Newfoundland in its western portion has much in common with 
Labrador, but owing to the effect of the surrounding ocean, the 
climate, especially in the east and south is much milder, and many 
species are found which belong to the temperate flora, rather 
than that of the sub-arctic zone. 1 

1 For a full account of the sub-arctic American flora, see Harshberger, J. W., 
Die Vegetation der Erde, Vol. XIII. 



CHAPTER III 
THE NORTH TEMPERATE ZONE 
EURASIA AND NORTH AFRICA 

The line between the sub-arctic and north temperate is a very 
ill-defined one. In western America, and western Europe, tem- 
perate conditions prevail much further north than in Asia or 
eastern America; but in general one may place the southern limit 
of the sub-arctic at about 55°. 

Between this and 30°, where sub-tropical conditions begin, is a 
vast expanse of land. Nearly all of Europe, except parts of 
Scandinavia and Russia, lie between these latitudes, which include 
also the Mediterranean littoral of Africa, the major part of Asia 
south of Siberia, and practically the whole of the United States 
and southern Canada. 

A large part of the sub-arctic flora, including all the trees, 
extends into the temperate zone, where the pines, firs, spruces, and 
larches; the poplars, birches, and willows, mingle with the beeches, 
maples, oaks, and other characteristic trees of the temperate 
zone. As all of these are represented by similar, if not identical 
species in Eurasia and America, the forests of the higher latitudes 
of the temperate zone have a general similarity of aspect, although 
very few species are common to the old and new worlds. 

The same is true of many shrubs and herbaceous plants, e. g., 
roses, honeysuckles, dogwoods, raspberries, elders, viburnums, 
etc. ; violets, lilies, buttercups, anemones, clovers, and many other 
familiar flowers; but there are many genera which are peculiar, 
or much less wide-spread. Thus America has no Narcissus, snow- 
drops, foxglove, broom or heath; while Europe has no mountain 
laurel (Kalmia), blood-root (Sanguinaria), Pentstemon or Tril- 
lium, and other lists could be extended indefinitely. 

These differences become more and more pronounced as we 
proceed southward, until the differences become much more 
pronounced than the resemblances. 

45 



46 OUTLINE OF PLANT GEOGRAPHY 

Western and Central Europe 

From the Baltic on the north to the great southern barrier of 
the Pyrenees, Alps and Carpathians, the whole of western and 
Central Europe constitutes a natural botanical province through- 
out which are found a large number of characteristic species. 

Within this area there is a good deal of difference in topography 
and climate, but the mountains, such as the Vosges and Harz are 
only of moderate height, never rising to regions of perpetual snow, 
and not forming barriers to the distribution of plants. 

The west coast, and the British Islands enjoy a comparatively 
equable climate, with much less severe winters and hot summers 
than the more easterly parts of the area. The effect of the proxim- 
ity of the ocean, and the prevailing westerly winds, together with 
the trend of the Gulf Stream, is evident in the very equable cli- 
mates of the west coasts of the British Islands, southern Iceland, 
and Norway, which have extraordinarily mild winters considering 
their high latitude. The contrast between the cool summers and 
mild winters of the south of England and west Ireland, and the 
hot summers and frigid winters of Poland is sufficiently striking. 

Much of Europe was originally forested but with the develop- 
ment of the dense populations now occupying it, practically all 
of the original forest has disappeared except in such remote regions 
as northern Russia or in the higher mountains. 

The forests of central Europe are much poorer in species than 
those of temperate North America. Probably the most wide-spread 
tree is the Scotch pine (Pinus sylvestris), which extends from the 
sub-arctic zone to the Alps and Pyrenees, and is pretty generally 
distributed through the whole of central and western Europe and 
the British Islands. The Norway spruce (Picea excelsa) and silver 
fir (Abies pedinata), are also very widely spread. Less abundant 
is the yew (Taxus baccata), and the common juniper, which can 
hardly rank as a tree, is perhaps the most wide-spread of all co- 
nifers. 

Much of the forest is composed exclusively of deciduous species. 
First in importance are two oaks, Quercus pedunculata and Q. 
sessiliflora, sometimes regarded as simply varieties of a single 
species, Q. robur. Oak forests are characteristic of a large part of 
western and central Europe and the British Islands. 



THE NORTH TEMPERATE ZONE 47 

Next in importance is the beech (Fagus sylvatica), common 
throughout northern Europe and often forming pure forests of 
great extent. The elm (Ulmus campestris) , and ash {Fraxinus 
excelsior) are large and important trees, but less common than the 
beech and oak. Lindens and maples also occur in this area. The 
Norway maple {Acer plata?ioides) and the sycamore maple (A. 
pseudo-platanus) , are trees of good size. 

In the southern part of central Europe the chestnut (Castanea 
vesca) is an important forest tree, but is still more abundant south 
of the Alps and Pyrenees, and in the mountains of the Mediter- 
ranean littoral. 

Among the smaller and less important trees are crab-apples, 
wild plums and cherries, mountain ash, hornbeam, hawthorn, 
and others, as well as the willows, poplars, birches and alders of 
the sub-arctic zone. 

In regions of poor soil there are often stretches of open country 
of great extent, forming heaths or moorlands covered with low 
growing shrubs mostly belonging to the heath family; huckle- 
berries, heather and others are sometimes mixed with the prickly 
gorse (Ulex) and bracken fern. The British moors when the 
common heather (Calluna vulgaris), or the golden gorse cover them 
with sheets of purple and gold, is a sight not soon to be forgotten. 

The regions immediately adjacent to the Alps and Carpathians 
include some of the most beautiful scenery in Europe. South 
Germany, Switzerland and Austria are sufficiently familiar to 
European tourists. 

Although the original forest has mostly disappeared, re-afforesta- 
tion has been developed extensively, as in the Black Forest and 
many other regions; but the greater part of the country is closely 
cultivated, or occupied by meadows and pasture-land. The 
traveller passing through this region in the early summer is at once 
struck by the beauty of the flower-decked grass-lands. A little 
later, the grain fields are gay with scarlet poppies and blue corn- 
flowers. Some of the meadow flowers like the tall buttercups and 
daisies, have become naturalized in the United States; but most 
of the European field flowers have failed to establish themselves 
in America, although some of them are seen in our gardens. 

Among the common meadow flowers are various yellow hawk- 
weeds (Hieracium spp.), as well as other Compositae, e. g., 



48 OUTLINE OF PLANT GEOGRAPHY 

Centaurea, thistles, blue Salvias, and Campanulas, pink catchfly 
(Silene, Lychnis); cowslips, geraniums, pinks (Dianthus), orchids, 
and numerous Umbelliferae. 

Many of the early spring flowers of the European woods and 
meadows, are also quite different from those of the eastern United 
States. It is true that in both regions, violets, spring cress, 
hepatica, anemones, buttercups and marsh marigolds abound; 
but the primroses and cowslips; the snowdrops, crocuses and 
narcissus, the Christmas roses and wild hyacinths and fritillaries, 
are absent from our eastern woods and meadows. So also are the 
foxgloves, scabious, poppies, and cornflowers of the early summer, 
except as these are occasionally escapes from the garden. 

Travelling eastward down the Danube, one enters the great 
Hungarian Plain, reminding one strongly of our own prairie region. 
This resemblance is increased by the great fields of maize, which 
might be in Kansas or Nebraska. The climate of this region is a 
decidedly continental one, much like the central United States, 
and the most abundant shade-tree of the region is an American 
one, the common locust, which seems very much at home in 
central Europe. 

To the east of the Carpathians, lie the similar plains of Rumania 
and southern Russia. 

The forests of the Carpathian region and the Balkans, are much 
richer in tree-species than the rest of central Europe, and a much 
greater amount of the original forest still persists. Most of the 
northern European trees reach this region, but in addition there 
are a good many other species both of conifers and deciduous trees 
and shrubs. 

Several species of oaks, e. g., the Turkey oak (Quercus cerris), 
and Q. Austriaca, belong to this region, and are often predominant. 
Beeches are abundant in some localities, but seldom occur in pure 
stands. With these are mingled hornbeams (Carpinus, Ostrya), 
elms, maples of several species, lindens, especially the silver 
linden (Tilia argentea), and chestnut. These make up a forest 
very much like the typical eastern American hardwood forest. 
Crab-apples, wild plums, cherries and pears also occur, and a 
number of handsome shrubs, some of which are in cultivation, 
are native to this region. Showy yellow brooms (Cytisus, spp.), 
roses, hawthorns, hazel, elder, barberry, buckthorn (Rhamnus), 



THE NORTH TEMPERATE ZONE 49 

and in some localities, lilacs are characteristic. The smoke-bush 
(Rhus cotinus) and flowering ash (Fraxinus ornus) also belong to 
this region. 

A truly alpine vegetation is richly developed in the high moun- 
tains which separate central Europe from the Mediterranean 
countries. The Alps, Pyrenees, and Carpathians reach high above 
the snow-line, and in these regions a numerous and beautiful high 
alpine flora is found. Many species are identical with arctic ones, 
but many others are peculiar to these high altitudes and each 
alpine district has many species peculiar to it. 

Near Vienna is a mountain, Schneeberg, only about 2000 
metres in height, but at the summit having a number of true 
alpine species. A visit to this mountain about the middle of June 
showed the snow was not yet all gone, and one found such typical 
alpine species as Anemone alpina, Ranunculus alpestris, Soldinella, 
Gentiana verna, G. acaulis, Primula auricula, and others. 

Lower down the mountain were columbines, kingcups (Trollius), 
Clematis, forget-me-nots, Pedicularis sp. and other sub-alpine 
species. Of course in the higher Alps the number of strictly alpine 
forms is much greater. 

In Switzerland the high alpine region above 2600 m. has accord- 
ing to Drude 1 388 species, of which 150 are arctic species, the others 
strictly alpine. 

The alpine region sometimes shows open grassy expanses, or 
meadows, beset with low growing plants, mostly dicotyledons, 
such as anemones, primroses, buttercups, gentians, etc., with 
relatively large and vividly colored flowers. 

Monocotyledons are less abundant as alpines. Among the 
commonest of these (apart from grasses and sedges), are the false 
hellebore (Veratrum), a few species of onions (Allium), and a 
small number of inconspicuous orchids. 

Of the dicotyledons, the Compositae, as usual, are the most 
abundant, for the most part familiar types like the dandelions, 
hawkweeds, flea-bane (Erigeron), asters, Arnica, golden-rods, 
mostly yellow in color, except Aster and Erigeron. To the Com- 
positae belongs also the Edelweiss (Leontopodiuni alpinum) 
and the low growing thistle-like Carlinia, a very common plant 
of the lower elevations. 

1 hoc. cit, p. 378. 



50 OUTLINE OF PLANT GEOGRAPHY 

The many rock-plants found at the higher altitudes consti- 
tute a very characteristic type of the alpine vegetation. These 
include various lichens and mosses, and a few small ferns, as 
well as numerous flowering plants, many of them related to 
those also found in the open meadows, such as gentians, Silene, 
Campanula, etc. Other genera like the saxifrages and stone- 
crops, and the little alpine poppies, are usually rock-plants. 
These are densely tufted, or form rosettes of leaves close to the 
ground, from which the flower-stalks arise. 

The snow-line in the Alps is about 10,000 feet elevation (3250 m.) 
but a considerable number of species may occur above this. 
Schroeter * lists 110 species in this category. 

Between the strictly alpine regions, and the lowlands, is an 
intermediate region, varying much in elevation, and other con- 
ditions, and supporting a very rich and varied sub-alpine flora. 
The beauty of the sub-alpine meadows of Switzerland and 
Tyrol is proverbial. 

About the end of June the meadows are solid beds of beauti- 
ful flowers in amazing variety, which almost entirely conceal 
the grass amid which they are growing. A little later, the grass 
grows above the mass of gay bloom, and flowers and grass are 
cut down together for hay. 

Among the beautiful meadow flowers noted by the writer at 
Cortina, in the Dolomite region of Tyrol, toward the end of June, 
were great masses of pale yellow pansies, f orget-me -nots, scabious, 
orchids of several species, many Umbelliferae, various clovers, 
vetches, lotus, and other Papilionaceae, many campanulas, daisies, 
buttercups, hawkweed, gentians, and in the lower, wet places, grass 
of Parnassus (Parnassia), cotton-grass (Eriophorum) and an 
orchis. 

In the adjacent woods, were many wood-anemones (A. nem- 
orosa), and hepatica, but the latter out of flower; kingcups 
(Trollius), marsh-marigold, spotted orchis, lily of the valley, 
Solomon's seal. The only European lady's slipper (Cypripediu?n 
calceolus) also grows near Cortina as well as two lilies (Lilium 
martagon and L. bulbiferum), but the latter was not yet in bloom. 
The pretty white St. Bruno's lily (Liliastrum) , however, was 
in full flower, and very attractive. 

1 Schroeter, C, Das Pflanzenleben der Alpen, pp. 612-613, Zurich, 1908. 



THE NORTH TEMPERATE ZONE 51 

At higher elevations gentians were abundant, especially the 
exquisite Gentiana verna, and the gentianella (G. acaulis), the 
alpine rhododendrons, " alpine rose" were common, as well as 
an attractive fragrant pink Daphne (D. cneorum). 

The British Islands 

The climate of the British Islands is much more equable than 
that of continental Europe in the same latitudes. Owing to 
the close proximity of the Gulf Stream to the west coasts of 
Great Britain and Ireland, these regions, in spite of their high 
latitude, have very mild winters, frost being rare in the south- 
west of Ireland and much of western Scotland. Many plants 
thrive in these regions, as well as in the south of England, which 
cannot endure the severe winters of continental Europe. In 
the southwest of Ireland are a number of native plants common 
to Spain and the Mediterranean regions, the best known being 
the strawberry tree (Arbutus Unedo), a near relative of the Cali- 
fornian madrono (A. Menziesii). 

The western regions of Great Britain and Ireland, have a 
very heavy rainfall, which combined with the absence of severe 
cold, makes these regions particularly adapted to the growth 
of many exotic broad-leaved evergreens, such as the laurels, 
rhodendendrons, and many New Zealand and Chilean ever- 
greens. Coniferous trees of many species do remarkedly well, 
and one may see fine specimens of Araucarias from Chile, red- 
woods and Douglas firs from the Pacific Coast, cedars of Lebanon, 
and many others. 

The indigenous trees, however, are few in number, and com- 
prise none not found also on the continent. 

The meadows and woodlands are very attractive in the spring 
with the primroses and bluebells in the woods, and the cow- 
slips and daisies in the meadows, the hedges white with haw- 
thorn bloom. But all of these are common to most of temperate 
Europe, and Britain has very few species peculiar to it. 

Much of Ireland and Scotland is occupied by bare moorlands 
and bogs, in which the cool damp climate induces extensive 
peat-formation, rendering much of the country unsuitable for 
agriculture. 



52 OUTLINE OF PLANT GEOGRAPHY 

The highest mountains of Britain scarcely exceed 4,000 feet, 
and there is no true alpine vegetation; but on account of the 
high latitude there are a few arctic and sub-arctic species which 
are found in the higher mountains of Scotland. 

As a whole, the British flora can hardly be considered a rich 
one. 

The Mediterranean Flora 

The Mediterranean region of Europe is very effectively pro- 
tected on the north by the high mountain ranges, and has a 
very different climate from central Europe. Very mild winters 
are the rule, and most of the rainfall is during the cooler half 
of the year, the summers being in many parts nearly or quite 

rainless. 

In the most protected districts, like the south of Spain, southern 
Italy and Sicily, the climate is especially adapted to the growth 
of oranges and lemons, and throughout most of the Mediter- 
ranean littoral, the olive, fig, and vine flourish. 

As might be expected, exotics from many lands of similar 
climate are at home about the Mediterranean. Palms from 
Egypt, California and China; Cacti and century plants from 
Arizona and Mexico; Eucalyptus and Acacias from Australia; 
pepper-trees and Bougainvillea from South America; Gerani- 
ums, Callas, Gladioli, Aloes, Mesembryanthemums, other showy 
flowers from South Africa, mingle with the native oaks and 
pines, and the roses, carnations and other familiar flowers in 
the gardens. 

Drude ! includes in the Mediterranean province, the islands 
off the west coast of Africa, i. e., Azores, Madeira and the Cana- 
ries, and all of Asia Minor as far as Persia and Mesopotamia. 

The regions most familiar to travellers are those immediately 
bordering on the Mediterranean. The European shores are 
mostly mountainous, and the bold coastal scenery of the French 
and Italian Riviera, southern Italy, Sicily, Dalmatia and Greece 
includes many world famous views. 

At the lower elevations the vegetation is largely evergreen. 
Among the commonest trees are the evergreen or Ilex oak (Quercus 
Ilex), the stone-pine (Pinus Pined) and the similar P. pinaster; 

1 hoc cit., p. 388. 



THE NORTH TEMPERATE ZONE 53 

olives and cypresses. Deciduous trees, e. g., elms and poplars, 
are by no means absent, and at moderate elevations in the moun- 
tains there are sometimes extensive chestnut forests, whose nuts 
are a very important article of food. In the highest mountains 
most of the central European trees are found. 

In northern Italy, including the beautiful lake region, quite a 
different climate prevails from that of the sea-coast. There is a 
much greater range of temperature than in the maritime districts, 
and a much heavier precipitation, especially in the lake region. 
There is an abundant summer rainfall, and the climate is very 
much like that of the warmer Atlantic United States, so that it is 
not surprising to find such characteristic American trees as the 
tulip-tree, black walnut and various oaks growing with unusual 
luxuriance in the parks of Milan and the gardens of the villas about 
Como. 

A very characteristic formation on the Riviera and elsewhere 
about the Mediterranean is the "Macchia" clothing the hill- 
sides with a dense thicket of evergreen, often thorny shrubs, like 
the " chaparral" of the Californian mountains. The macchia is 
made up of a great variety of shrubs, many very ornamental. 
Among these are the Arbutus, laurels, heaths, rock-roses (Cistus 
spp.), brooms, and others often seen in cultivation, as well as some 
not so familiar. 

The only native European palm, Chamaerops humilis, not unlike 
the scrub palmettos of Florida, occurs in the warmest parts of the 
Mediterranean littoral. It is especially common in southern Spain 

and Sicily. 

Many showy bulbous and tuberous plants abound in the Med- 
iterranean region, and are more or less familiar in cultivation. 
Among these are magnificent blue and scarlet anemones, various 
species of narcissus and tulips, crocuses and snowdrops, gladioli 
and iris, as well as some attractive ground orchids. 

The Mediterranean region is preeminently the land of the vine 
and olive, both of which are native, and cultivated from time im- 
memorial. Wheat is universally cultivated, and in many regions, 
maize is now a very important crop. Rice is also grown both in 
Spain and Italy. Fruits and vegetables of many kinds are an im- 
portant element in the diet of all Mediterranean peoples. 

Especially in the south of France, the cultivation of flowers on 



54 OUTLINE OF PLANT GEOCJKAPHY 

a commercial basis is B very important industry. Immense quan- 
tities of cut flowers are shipped from the Riviera to Paris and 
London, and certain fragrant flowers like violets, lavender, jas- 
mine, etc., are grown in great numbers for the manufacture of 
perfume. 

The Iberian Peninsula j 

The Iberian Peninsula, Spain and Portugal, forms a very dis- 
tinct botanical province in which the Mediterranean flora is pre- 
dominant over much of the area, but which has also a strong 
element related to western and central Europe. Owing to its 
isolation it has an unusually high percentage of endemic species. 

Except for the lofty Pyrenees separating it from France, the 
whole of the peninsula is bounded by the Atlantic Ocean and the 
Mediterranean, which exercise a great influence on the climate 
of the coastal region-. 

The greater part of the peninsula is occupied by a plateau, 
between 2,000 and 3,000 feet elevation. This plateau, being largely 
cut off from the coast by mountains, has a very different climate. 
It is divided into a northern and southern portion, which differ 
considerably in their climate and flora. 

The plateau is highest on its eastern side sloping somewhat 
gradually to the west, before descending to the lowlands of Portu- 
gal, which are drained by the Douro and Tagus, flowing between 
ranges of considerable elevation. 

The southern edge of the plateau is bounded by the Sierra 
Morena, between which and the lofty coastal Sierra Nevada, is 
the broad Andalusian plain, watered by the Guadalquivir, a region 
of great fertility. 

The northern and northwestern coasts are extremely rugged, 
the mountains often coming down to the sea, and tins region, 
together with the Pyrenees, is the rainiest part of the peninsula. 

Contrasted with this is the eastern or Mediterranean coast, 
which has for the most part a scanty rainfall, and in places is so 
arid as to warrant the appellation of steppes, which is also true 
of much of the eastern plateau. Arid conditions prevail over much 

1 For a detailed account of the flora of Spain and Portugal, see Willkomm, 
M., Pflanzenvcrbreitung auf dir iberischen Halbinsil. Die Vegetation der Erde, 
Vol. I. 1S96. 




55 



56 OUTLINE OF PLANT GEOGRAPHY 

of the Ebro valley, a broad plain between the base of the Pyrenees 
and the range bounding the plateau to the west. 

Salt marshes, sandy beaches and extensive dunes occur in cer- 
tain parts of the coast, e. g., Portugal and southern Spain; but 
along the Mediterranean the coast is much like that of southern 
France and Italy. 

The varied topography of the peninsula is reflected in its climate. 
The whole coast enjoys a mild climate, this being most evident in 
the extreme south, the southernmost point of continental Europe, 
with the warmest winter climate. The contrast between the cli- 
mate of this part of Spain, and that of the bleak elevated plateau 
may be shown by comparing Madrid and Gibraltar. The average 
winter temperature for the former is 5.2°C, the summer, 29.9°C; 
for Gibraltar, 12.5° and 22.6°, about the same as Los Angeles. 

The rainfall varies from 1,647 mm. at Santiago in the mountains 
of the northwest coast, to 275 mm. at Salamanca, in the northern 
plateau. 

This great difference in temperature and precipitation, as well 
as the marked differences in elevation and soil, result in a flora of 
great richness, with a higher degree of endemism than is found 
anywhere else in Europe. 

This is clearly shown in the forest flora, for although only about 
5% of the peninsula is forested, there are more species of trees 
than in any other European country. 

As one enters Spain from the north, one passes through the 
gorges of the Pyrenees, well -wooded, and evidently having 
abundant rainfall. The general aspect of the forest is that of 
central Europe, the same deciduous trees, oak, ash, and chestnut 
predominating, while silver fir, Scotch and Austrian pines are 
the prevailing conifers. The deciduous forest and the Scotch 
pine are characteristic of the lower elevations, while the firs and 
Pinus laricio, are found in the higher regions. 

There is an abundant alpine flora in the Pyrenees, many of the 
species being the same as those of the Alps; but there are also a 
good many endemic species as well. 

While much of the vegetation of the lower slopes of the Pyrenees 
is evidently related to that of central Europe, there is an inter- 
mingling of forms belonging to the Mediterranean flora, such as 
Arbutus, the laurestinus (Viburnum tinus), and laurels. 



THE NORTH TEMPERATE ZONE 57 

Travelling southward, one soon enters the great table land 
which makes up the greater part of Spain. The northern part of 
the plateau has sufficient rainfall for the growth of grain, especially 
wheat and barley, and this is the great granary of Spain, reminding 
one of the great wheat fields of Kansas or the Dakotas. Like our 
prairie states, the plains are quite destitute of trees, and only in 
the beds of streams, does one see elms, poplars, alders and willows. 

Madrid and Toledo lie in an arid region, which might be called 
a desert. The barren often saline soil supports only the scantiest 
vegetation, such as salt-bush (Atriplex and Salsola), species of 
plantain, Gypsophila, Lepidium, Sonchus, Lavatera, and several 
Leguminosae. The great stretches of gray barren plain are most 
depressing, and the climate extremely trying. 

The southern plateau has a much better climate, and here for 
the first time one meets the olive, growing in veritable forests, as 
well as vines, figs, peaches, pomegranates and apricots, and in 
specially sheltered regions, oranges. 

A feature of the landscape of the southern plateau is the exten- 
sive woods of evergreen cork oak (Quercus suber) whose bark is 
an important article of commerce. 

It is in the coastal regions, especially at the south that one finds 
the most favorable condition for the growth of sub-tropical vegeta- 
tion. About Seville or Gibraltar one sees the same ornamental 
plants that one sees in Santa Barbara or San Diego; and as in 
southern California, irrigation is necessary. 

Besides the usual products of the Mediterranean, rice and cotton 
are also grown to some extent, and the date palm is more exten- 
sively grown than anywhere else in Europe. 

Eucalyptus and pepper trees are common, and in Gibraltar one 
is struck by a curious shade tree the "Bella Sombra," a native of 
Argentina, closely related to the common " poke-weed ' : of the 
eastern United States. 

Two conspicious American plants have escaped from cultiva- 
tion and became thoroughly naturalized, the prickly-pear cactus, 
and the century plant (Agave), both probably introduced from 
Mexico. The prickly-pear is a serious pest in some places. 

The extreme south of Spain, as might be expected from its close 
proximity to Morocco, has much in common with northern Africa, 
both in its climate and vegetation, the floras of the two sides of 



;>s 



OUTLINE OF PLANT GEOGRAPHY 



the straits of Gibraltar being very much alike. The climate is 
especially favorable for all kinds of Citrus fruits, and even bananas 
will ripen in some Localities; and sugar cane and cotton, are among 
the products of this region. Raisins and figs are produced in large 
quantities, and in the hot dry regions of the southern Mediter- 
ranean coast, date palms thrive and ripen their fruit as well as in 
Morocco or Algeria. 

Fonsts 

The forests of Spain are largely restricted to the mountainous 
districts. In the higher parts of the Pyrenees there are forests of 




Fig. 7.— Ilex oak. Island of Majorca. Photo., Dr. H. Knoc 

silver fir and Norway spruce, but except for an endemic fir (Abies 
Pinsapo) restricted to a limited area in the higher mountains of 
southern Spain, the conifers are all species of pines, of which per- 
haps the stone pine (P. pined) is the most notable. This species 
and the somewhat similar P. pinaster, are common over most of 
the Mediterranean littoral. In the south occurs also the Aleppo 
pine, P. Halepensi*. 

The deciduous forests are especially characteristic of the north- 
ern mountain regions. The predominant trees are chestnuts. 



THE NORTH TEMPERATE ZONE 59 

beeches, and oaks of several species. Further south these are re- 
placed by evergreen oaks, including the Ilex oak, and cork oak, 
and next in importance is the olive, which forms extensive woods 
in a wild state, and is widely planted for its fruit. 

The forests, especially in the drier regions, are open, with much 
undergrowth, and the trees of small size; and all gradations between 
these open woods, and trees growing alone, or in small groups, 
may be met with. 

Much of the drier country in Spain is covered with a more or 
less dense growth of shrubs and undershrubs. In the cooler dis- 
tricts of the northwest are extensive heaths composed entirely 
of species of Erica, but more commonly these shrub formations are 
composed of a variety of forms, such as woody labiates like laven- 
der and rosemary; rock roses (Cistus); many species of broom and 
other woody Papilionaceae. The woody Labiatae are remarkably 
abundant and make an important element in the Spanish flora, and 
the genus Cistus is also represented by many species, which often 
forms pure stands of great extent. 

Among the most showy of the Spanish shrubs are the many 
species of broom (Cytisus, Genista, Spartium), covered with 
masses of vivid golden bloom. The " Spanish broom," Spartium 
junceum, often seen in cultivation, is one of the most abundant 
species. 

Another showy shrub, abundant along stream banks in southern 
Spain, is the common oleander. 

The following 1 are the largest families given in order: 1. Com- 
positae; 2. Papilionaceae; 3. Gramineae; 4. Cruciferae; 5. Labia- 
tae. 

Ths islands of the Mediterranean, viz.: the Balearic Islands, 
Sardinia, Corsica and Sicily, Cyprus and Crete, while showing 
a small percentage of endemic species, have a flora made up for 
the most part of wide-spread species common to the adjacent 
mainland. 2 

1 Willkomm, loc. cit., p. 64. 

2 Knoche, H., Flora Balearica, Elude Phytogeographique sur les lies Balcarrs, 1023. 



60 



OUTLINE OF PLANT GEOGRAPHY 



Northern Africa * 

The western Mediterranean regions of Africa, both in topog- 
raphy and climate, much resemble the opposite European 
coast, this being especially the case in Spain, which is separated 
from Morocco only by the narrow Straits of Gibraltar. As might 
be expected, a great many species in Morocco and Algeria, are 




Fig. 8. — Chaparral formation, "Macchia," Island of Minorca. Cistus monspelien- 
sis, dominant; Myrtus communis, Pistacia Lentiscus, Olea sylvestris, Phyleria 
angustifolia. Photo., Dr. H. Knoche. 



either identical with European ones, or closely related to them. 
These, however, are associated with many species of undoubted 
African origin. 

Parallel with the coast is an extensive system of mountain 
ranges, beginning in western Morocco, and extending to Tunis. 
These mountains are highest in Morocco, culminating in the Great 
Atlas, probably exceeding 12,000 feet elevation. 

In Algeria there are two main ranges, the maritime Atlas, and 
the Saharan Atlas whose highest peaks are less than 8000 feet, 

1 Englor, A., Die Pflanzenwelt Africas, Die Vegetation der Erde, Vol. 
IX, 1910. 



THE NORTH TEMPERATE ZONK 



61 



and between them is a barren plateau with an elevation of about 

3,000 feet. 

Back of the coast extends for fifty miles or more a broken region, 
the "Tell," largely covered in its original state, by a dense growth 
of evergreen shrubs, the "macchie" of the Italian Riviera, and 
composed largely of the same Bpecies. 

Further inland there is a decided falling off in the rainfall, and 




MS- 




Fig. 9. — Dwarf palm {Chamaerops humilis) Cala Retjada, Majorca. 

Photo., Dr. H. Knoche. 

the base of the Great Atlas of Morocco is occupied by a barren 
steppe. In Algeria this drier zone is characterized by the presence 
of the Aleppo pine (Pinus Hcrtepensis), two junipers and a peculiar 
conifer, Callitris quadri veil vis, the only representative of a genus, 
otherwise restricted to the southern hemisphere. 

Where the rainfall exceeds GO cms., woods of cork oak and olives 
occur on the lower slopes of the mountains, and in the drier dis- 
tricts extensive growths of the scrub palms occur as they do in 
southern Spain and Portugal. The Carob (Ceratonia sUiqua) is 
also a common tree. 



62 



OUTLINE OF PLANT GEOGRAPHY 



In moist ground, both in the lowlands and hills, elms, poplars, 
ash, oleander and laurel are found, and in the mountains, from 
3,000 to 4,000 feet, there is developed a forest containing a variety 
of trees both evergreens and deciduous. 

First in interest is the Atlas cedar (Cedrus Atlantica) often 
considered to be merely a variety of the cedar of Lebanon. As- 
sociated with this are several oaks (Quercus ballota, Q. lusitanica) 
species common to Spain, and also the fir Abies Pinsapo, also a 




Fig. 10. — Aleppo pine, Cap Formentor, Majorca. Photo., Dr. H. Knoche. 



tree found elsewhere only in Spain. The yew also occurs in these 
mountains, and many other types common to central Europe, 
e. g., holly, almond, chestnut, bird-cherry, crab-apple, honeysuckle, 
maple, goose-berry. Nowhere in Africa are the boreal types so 
abundant as in the mountains of Morocco and Algeria. 

The alpine floras are poorly developed, but in the highest parts 
of the Atlas, there is a considerable number of alpine or sub- 
alpine species which are identical with those in the Pyrenees and 
Sierra Nevada of Spain, or even the western Alps. In the highest 
altidudes of the Great Atlas are also several endemic species. 



THE NORTH TEMPERATE ZONE 



63 



The barren plateau region is very poor in species, the most 
characteristic being coarse tussock grasses, of which one, the 
" Haifa grass" (Stipa tenacissima) is of importance in paper 
making. The steppes may be rocky, sandy or saline, with cor- 
responding differences in the vegetation, which is even-where 
meagre. Trees are absent, and occasional shrubs, tamarisk, 
pistache or tall stalks of fennel, are all that break the monotony 
of the barren wastes. 




Fig. 11. — Mt. Atlas cedar, Algeria. Photo., Dr. W. A. Cannon. 

In the drier regions to the south the vegetation becomes more 
decidedly African in character, cactus-like Euphorbias, Mesem- 
bryanthemums, Acacias, and others being features of the flora. 

The south side of the Saharan Atlas exposed to the hot dry 
winds of the Sarhara has very scanty vegetation, and the great 
Sahara itself is notoriously barren. 

From Tripoli eastward, there are no mountains of importance 
and the shores of the Mediterranean are largely made up of sandy 
beaches and dunes. The rainfall diminishes rapidly eastward, 
and the desert reaches to the sea coast. In the oases, there is a 
limited number of plants, aside from the date-palms. Among 



64 



OUTLINE OF PLANT GEOGRAPHY 



these may be mentioned tamarisk, colocynth (Citrullus colocyn- 
thus), docks, capers, Reseda, mesquit (Prosopis), Cassia, Astrag- 
alus, Convolvulus and various grasses. 1 

The rich lands of the Nile delta are intensively cultivated, and 
yield abundant crops of clover, beans, rice, cotton, sugar and flax, 
as well as the usual fruits of the Mediterranean. Tamarisk, 
willows, acacias and the sycamore fig are common, and water- 




Fig. 12. — Edge of desert, Algeria. Village with date-palms in background. 

Photo., Dr. W. A. Cannon. 



plants of many kinds, including the lotus (Nymphaea lotos) abound. 
The climate of Morocco and Algeria is very similar to that of 
southern California. With the autumn rains, the dominant 
vegetation starts into life, and the lower mountain slopes and val- 
leys are quickly covered with fresh grass and many showy flowers. 
There is a great development of bulbous or tuberous plants. 
Gladioli, Iris, Narcissus, star-of-Bethlehem, etc., which come up 
quickly, some like the colchicums and species of Narcissus, flower- 
ing in the autumn, others continuing through the winter and early 

1 For details of the desert floras, see Engler, loc. cit., Vol. I, pp. 15-45. 



THE NORTH TEMPERATE ZONE 



65 



spring, when the numerous annuals flower in great profusion, 
making brilliant masses of color, like the poppies and lupins of the 
California spring. Some of these, like the scarlet flax, and the 
Morocco toad-flax (Linum Maroccanum), Convolvulus mauretani- 
cus and others are sometimes seen in our gardens. 

The coastal regions of Algeria are very fertile, and large areas 
are devoted to the raising of wheat, barley and oats, as well as the 













Fig. 13. — Stony desert, northern Sahara, Algeria. Photo., Dr. W. A. Cannon. 

usual vegetables, and fruits of the south of Europe. In the hotter 
districts, dates are extensively grown, and the vine and olive are 
important crops. As in southern Spain, the cork oak is of great 
importance. 

The Atlantic Islands 

The isolated island groups lying off the northwest African coast, 
Azores, Madeira and the Canaries, are characterized by a high 
degree of endemism, and the flora shows a mingling of Mediter- 
ranean and African types. 



66 OUTLINE OF PLANT GEOGRAPHY 

There is a marked development of the evergreen macchie, 
with heaths in great variety, brooms and rock-roses, as in Spain 
and Portugal. Much of the forest formation, however, is very 
different, being composed mainly of species of true laurels (Laurus, 
Persea, and Oreodaphne), a family very poorly represented in 

Europe. 

In the drier regions, especially in the Canaries, ! is a marked 
development of succulent plants, like stone-crops, Aloes, Eu- 
phorbias, and others, as well as many showy plants adapted to 
xerophytic conditions. 

Two characteristic trees, the Canary Island date-palm, and 
pine (Pinus Canaricnsis) are extensively planted in warm tem- 
perate regions like the Riviera and California. Less frequently 
is seen in cultivation, the extraordinary dragon-tree {Dracaena 
draco), from Madeira and the Canaries. 

The Eastern Mediterranean 

To the east of the Mediterranean lie the lands of Palestine, Asia 
Minor and Mesopotamia, which Drude includes in the Mediter- 
ranean area. 

This region lying between 30° and 40° N. lat. may be compared 
with southern California, Arizona and northern Mexico, lying in 
approximately the same latitudes and having very similar climatic 
conditions. The coastal region has the characteristic temperate 
Mediterranean climate, but inland are regions where the range 
of temperature is very great, intensely hot summers, and relatively 
severe winters. The region at the head of the Persian Gulf is one 
of the hottest known, and might be compared with Death Valley 
in southern California. 

This region comprises elevated plateaus surrounded by lofty 
mountains, and the lowlands of Mesopotamia. The rainfall is for 
the most part scanty, and much of the region is occupied by 
steppes, or actual deserts, with very scanty vegetation of salt- 
bushes, sage-brush, various Polygonaceae and in regions where 
there is a marked winter rainfall, in the early spring is a growth of 
short-lived annuals, mostly inconspicuous species. 

1 For a complete description of the flora of the Canaries, See Knoche, H., Va- 
gandi Mos — Rciscskizzen eincs Botanikcrs: I. Die Kanarischcn Inseln, Strasbourg, 
1923. 



THE NORTH TEMPERATE ZONE 



67 



The region about the Persian Gulf is supposed to be the original 

home of the date-palm, now so extensively cultivated in Arabia 
and northern Africa, and recently introduced into the hottest 
parts of southern California and Arizona. 

Asia Minor is extraordinarily interesting historically, as the 
alleged cradle of the human race, and has been inhabited from 
earliest historic times. It is almost certain that the ancestors of 
the most important European cultivated plants were derived from 



jfe^tfSr- ' - 





Fig. 14. — Sandy desert, northern Sahara. Photo., Dr. W. A. Cannon. 

species indigenous to this region. Wheat, barley, the vine, fig 
and pomegranate are still represented by wild species which were 
the probable progenitors of all the varieties now in cultivation. 

The dry steppes are surrounded by mountains, some of great 
elevation, like the Caucasus and Lebanon, and the highest eleva- 
tions are covered with perpetual snow. These mountains in many 
regions, have a well-developed forest belt, and a true alpine flora. 

In the mountain forests of the Balkan regions, and the Caucasus 
are a number of trees, absent from central Europe 1 and the northern 
Mediterranean. Among these are several conifers, firs and sprue 3, 
but in addition genera quite absent from Europe The- walnut 



68 OUTLINE OF PLANT GEOGRAPHY 

(Juglans regia), Pterocarya, sweet gum (Liquidambar), honey- 
locust (Gleditschia), and plane-tree (Platanus orientalis) are all 
more nearly related to North American and Chinese trees, than 
to those of Europe. In the same category are showy rhododendrons 
and azaleas. All of these may be considered as relics of the ancient 
Tertiary flora, which became extinct in Europe. 

In the Lebanon range of Palestine occur the famous cedars of 
Lebanon, closely related to the Atlas cedar, already referred to. 

The higher mountains harbor an extensive alpine flora, many 
species being the same as those of the Alps, but with a large element 
of peculiar species. 

The interior of Asia is a barren region with an intensely con- 
tinental climate and meagre rainfall, so that much of it is quite 
unfitted for human habitation, and indeed is still unexplored. 
From the Caspian Sea to China, and from the Himalayas to the 
Altai, the country is largely barren mountains and desert uplands. 
For the most part it is treeless, and vast stretches are absolutely 
bare of any vegetation. Where conditions allow a meagre growth 
of stunted shrubs, they are mostly salt-bush, wormwood, and 
similar desert species. 

In the less arid regions, especially in the western portion, there 
is a brief display of herbaceous plants in the spring. Among these 
are some fine bulbous plants, tulips, fritillaries, iris, and others 
which soon ripen their seeds, die down and remain dormant for 
most of the year. 

Southward, however, following the great Himalayan range, 
there is developed an extremely rich temperate flora, which links 
that of the Mediterranean with temperate China and Japan. 

The Himalayan Regions 

The great Himalayan region constitutes one of the most impor- 
tant botanical areas of the world. This loftiest of all mountain 
ranges is a link between the Mediterranean lands and eastern 
Asia, and the flora is a remarkable mingling of types belonging 
to both regions. 

The lower elevations of the Himalaya, rising from the great 
Indian plain, have a truly tropical flora made up mostly of strictly 
Indian types; but above the tropical belt there are successive 




Plate II. — Forest at base of Himalaya, Darjiling railway. 



69 



70 OUTLINE OF PLANT GEOGRAPHY 

zones passing through all degrees of temperate and arctic climate 
to the regions of everlasting snow and ice. 

The temperate zone begins at about 5,000 feet elevation, but 
the distribution of the temperate flora is controlled both by eleva- 
tion and moisture. In the eastern parts of the Himalaya are 
regions of excessive rainfall, reaching a maximum in the lower 
ranges about the head of the Bay of Bengal. Westward there is a 
marked diminution in rainfall, and a corresponding falling off in 
the luxuriance of the forests. This is true also on the northern 
slopes, which descend to the great Tibetan highlands, among the 
most desolate and forbidding regions of the world. 

The western Himalayan temperate forests have much in common 
with those of Europe. Oaks, ashes, elms, poplars, maples and 
other familiar genera, predominate, giving place at higher eleva- 
tions to willows, alders and other sub-arctic and arctic forms, 
which are replaced at still higher altitudes by a genuine arctic- 
alpine flora which reaches to the limits of vegetation. 

Coniferous trees, pines, firs, larch, yew and cypress are common, 
and the Atlas and Lebanon cedars are represented by the beautiful 
Deodar. Of the pines, Pinus longifoHa, and P. excelsa are the most 
important. Walnuts, horse-chestnuts and plane-trees are rem- 
iniscent of the forests of Asia minor and the Balkans. 

Eastward, as we have seen, the rainfall increases rapidly, and 
this is accompanied by a decided change in the flora. Conifers 
are much less prominent, and the European element is to a great 
extent superseded by species related to those of Japan and China 
which in turn have a strong relationship with many American 
species. A forest of this type may be seen in the neighborhood 
of Darjiling, whose unrivalled panorama of the main range of the 
Himalaya is world famous. 

Darjiling lies at an elevation of about 7,000 feet, and has an 
annual rainfall of 120 inches, so that the forest is a very luxuriant 
one. It is a mixed forest of deciduous and evergreen angiospermous 
trees. Oaks are perhaps the most abundant trees, but with these 
are associated maples, laurels, birches, chestnuts, and especially 
characteristic are several species of magnolias and tree rhododen- 
drons. Magnolias are quite absent from Europe and western Asia, 
but a conspicuous feature of the eastern Asiatic and North Amer- 
ican floras. Both Magnolia and Rhododendron comprise some 




A,JT a. 






■:&&£* •'. */ ■ 



■ « 

&* i\ ' 'AW ' 



Plate III. — Forest below Darjiling, about 4,000 (?) feet elevation ; at left, 

Duabanga Sonneratioides. 



71 



72 OUTLINE OF PLANT GEOGRAPHY 

of the most beautiful known flowering trees and shrubs, the latter 
reaching their finest development in the Himalayas where they 
may become trees of some size. One of the finest of these is R. 
arbor cum, a spreading tree as large as a good sized apple tree, and 
in the spring adorned with clusters of blood-red flowers, once seen 
never to be forgotten. 

Crab-apples, cherries, hydrangeas, dogwoods, cotoneasters, bar- 
berries, roses, spiraeas, are among the many ornamental shrubs 
which abound in the Himalayan forests. 

Among the evergreen shrubs which are distinctly east Asiatic, 
are several members of the tea family, Thea, Camellia, Gordonia. 
This family is also represented in the south Atlantic United 
States. 

The very humid climate induces an abundant growth of mosses 
and ferns, and also many epiphytes, among which are some very 
handsome orchids, including many species of Dendrobium, some 
of which are highly prized in cultivation. 

Hooker l gives a very graphic account of the transition from the 
strictly tropical vegetation of the "Terai" the forest region at the 
foot of the mountains, to the temperate flora as one approaches 
Darjiling. 

At 4,000 feet he notes the appearance of raspberries, deciduous 
oaks and birches, maples, violets, chickweed, strawberries, gera- 
niums, and other temperate plants, but with these are growing 
tree-ferns, and such tropical forms as palms, figs, peppers, bamboos, 
bananas, climbing arums, and many epiphytic orchids, some of 
these tropical forms extending well into the temperate regions. 
Owing to the great humidity and mild temperature prevailing 
here, this region has a much more uniform climate than prevails 
at similar altitudes in the western Himalaya. 

The region beyond the summit of the main range, Sikkim, was 
carefully studied by Hooker, who states that this district is most 
remarkable as a meeting place for representatives of most of the 
plant-types characteristic of the temperate regions of both the old 
and new worlds. In addition are many species belonging to the 
Indo-Malayan flora. Of American genera not occurring in 
Europe, he mentions the following; Buddleia, Magnolia, Sassa- 
fras, Hydrangea, Aralia, Trillium, while characteristic Chinese and 

1 Himalayan Journal, I, p. 99. 



I 

o be 



1 c3 



i 

o 



a 
be 

d 

3 



< 
►J 



d § 

.S o 




73 



74 OUTLINE OF PLANT GEOGRAPHY 

Japanese genera were Camellia, Deutzia, Aucuba, Skimmea and 

Enkianthus. 

The recent discoveries of palaentologists in Mongolia, pointing 
to that region as the original home of the ancestors of most of the 
large mammalia of both hemispheres, suggest that possibly some- 
where in central Asia was also the region from which were derived 
the ancestors of all the boreal floras. 

Eastern Asia 

The temperate regions of eastern Asia are comprised in the 
Chinese Empire, Corea, and Japan. 

As might be inferred from its vast extent China possesses a very 
extensive and varied flora. The southern portion lies within the 
tropics, and the flora is Indo-Malayan in character, like that of the 
adjacent Himalayan and Burmese regions. 

The mountains of the south and west, however, have a very rich 
flora of a more temperate character, being part of the Himalayan- 
Tibetan region. It is these mountain regions from which have 
come so many beautiful Chinese plants which adorn our gardens. 

China, being such an ancient and densely populated country, 
has little to offer the botanist except in the more remote regions. 
Most of the land has been so long closely cultivated that it is quite 
impossible to find any trace of the original vegetation. More- 
over the mountains have been stripped of their forests, resulting 
in extensive denudation, so that the student of the indigenous 
Chinese flora must seek the remote, and thinly settled mountain 
regions of the south and west. 

In the valley of the Yangstse Kiang, the upper forest is said 
to be composed largely of conifers. At 6000 feet elevation there 
are firs, spruces, larch, not unlike the European forests at similar 
altitudes, but composed of different species. Below is a mixed 
forest of conifers and deciduous trees similar to that in northern 
Japan and the eastern United States. The common European 
genera are all present; but with these are many types absent 
from Europe, but represented in North America. Such char- 
acteristic American trees as the sweet gum (Liquidambar), 
tupelo (Nyssa), tulip-tree (Liriodendron), Magnolia, Catalpa 
and others, have Chinese representatives, and there are many 



i 




75 



76 OUTLINE OF PLANT GEOGRAPHY 

shrubs and herbaceous plants having a similar distribution. 
Witch hazel (Hamamelis), Sassafras, Virginia creeper (Ampe- 
lopsis), bittersweet (Celastrus), honey-locust (Gleditschia) Hy- 
drangea, Wistaria, mandrake (Podophyllum), moon-seed (Meni- 
spermum), are a few of these, Asiatic-American genera. 

All of the European genera of conifers occur in China, and 
there are several genera peculiar to China and Japan. Among 
these Cryptomeria, Sciadopitys, Cunninghamia, Glyptostrobus, 
and the Yew-like Cephalotaxus. Another of the Yew-family, 
Torreya, has two species, two others being found in California 
and Florida. 

The most peculiar tree, however, is the Ginkgo, a single 
species which is the only survivor of a very primitive type which 
flourished in the early Mesozoic. This tree, like the "Tree of 
heaven" (Ailanthus), and the white mulberry, is sometimes 
seen in the United States, where it seems to be quite at home, 
as do many ornamental plants, like Wistaria, Forsythia, Weigela, 
Daphne, peony and other ornamental garden shrubs and her- 
baceous plants. 

China and the temperate Himalaya seem to have been the 
centre of development of the rhododendrons and azaleas, of 
which China is said to possess over a hundred species, compared 
to four in all of Europe. The wetter regions, especially in the 
south, are extraordinarily rich in ferns, and the warmer parts 
have many species of bamboos. 

China is supposed to be the original home of the peach, forms 
of which occur wild, and it is possible that the orange is the 
product of one of the wild species of Citrus which are found 
in southern China; but the different citrus fruits have been so 
long in cultivation, that their origin is very uncertain. 

While most of southern and central China has usually an 
adequate rainfall, the northwest portions merging into Mon- 
golia are arid, and much of the country is a dry steppe or even 
desert, with an extremely severe climate exhibiting great extremes 
of heat and cold. Indeed all of China has a pronounced con- 
tinental climate. 

Many of our choicest garden plants have come from China. 
A Chinese rose, R. Chinensis, crossed with other species has 
furnished the tea roses, and many others, and the fine climbing 



THE NORTH TEMPERATE ZONE 



77 



V!^£ 











Fig. 15. — Ginkgo, a peculiar Chinese tree, Stanford University. 
Photo., Dr. L. L. Burlingame. 



78 OUTLINE OF PLANT GEOGRAPHY 

roses, the Banksia, Cherokee, and Fortune's yellow are of Chinese 
origin. Peonies, Dicentra, lilies, among herbaceous plants, Wis- 
taria, lilacs, Deutzia, Spiraeas of several species, azaleas, Daphne, 
flowering plums and crab-apples and peaches are a few of the 
contributions of China to our gardens. 

Japan 

The chain of islands forming Japan extends for about fifteen 
degrees of latitude 30°-45°, corresponding therefore to the At- 
lantic States between Maine and northern Florida, and show- 
ing much the same range of climate. However, due to insular 
conditions, the Japanese climate is somewhat more uniform, 
and very decidedly milder than the adjacent coast of the Asiatic 
mainland in the same latitudes. 

The influence of the sea is also shown in a more abundant 
and better distributed rainfall, Japan being quite destitute of any 
arid regions, the country naturally being well wooded through- 
out. In spite of the dense population of the lowlands, there is 
everywhere an abundance of trees, probably planted in most 
cases, but the Japanese are such skilful landscape artists that 
it is quite impossible to tell where nature leaves off and art begins. 

The Japanese love of beautiful scenery has made all the most 
attractive parts of the country readily accessible, and it is easy 
to get into the mountains where the interesting native vegeta- 
tion may be seen in all its wild luxuriance. 

In southern Japan there is an admixture of Malayan types 
like bamboos, Cycas, palms and others; but the flora as a whole 
is a temperate one and has much in common with the eastern 
United States. In the northern island, Hokkaido, which is 
much less densely populated, there is still a good deal of low- 
land forest, which is entirely boreal in its constituents. 

The southernmost island, Kiushiu * shows the largest per- 
centage of Malayan types. The forest is made up almost entirely 
of broad-leaved evergreens, of which the most abundant are 
several species of evergreen oaks. Another characteristic tree 
is the camphor {Cinnamomum camphora), and other members 
of the laurel family. Camellias and others of the tea family 

1 Schimper, A. F. W., Pflanzengeographic, pp. 516-518, 1898. 







Plate VI. — Gorge of a tributary of the Yangtse River, South Central China, 
elevation 3,200 feet. Photo., Dr. Bailey Willi*. 



79 



80 



OUTLINE OF PLANT GEOGRAPHY 



are abundant, and the handsome Pittosporum tobira, often seen 
in Californian gardens. The magnolia family is also well repre- 
sented. More suggestive of the tropics are several epiphytic or- 
chids (Dendrobium, Malaxis and others), as well as a good many 
epiphytic ferns. Begonias, peppers, and several members of the 
banana family (Scitamineae) are also reminiscent of the tropics. 




Fig. 16. — Two favorite garden flowers from Japan; Anemone Japonica, 

Liliuin duration. 



Owing to the close cultivation of the land there is not much to 
be seen of the native vegetation in the densely populated areas 
near Yokohama and Kyoto. Along the roadside banks and 
ditches, a few wild plants find a foothold, one of the most pe- 
culiar, in summer, being Houttuynia, closely related to the lizard- 
tail (Saururus) of eastern America, but having four white bracts 
subtending the spike of flowers. 

Not infrequently one catches a glimpse from the car windows of 



THE NORTH TEMPERATE ZONE 81 

the great golden-banded lily {Lilium auratum), growing on the em- 
bankment. This magnificent flower, one of the most prized of gar- 
den plants, is common in the country near Yokohama. One of the 
writer's most vivid recollections of Japan is that of thousands of 
these splendid lilies adorning the steep sides of a gorge, on the road 
to the well-known resort Miyanoshita, in the Hakone mountains. 

The principal cities of Japan are in the southern part of the main 
island, in about the latitude of the Carolinas. The summer is hot 
and rainy, with a correspondingly luxuriant vegetation. The 
winters are comparatively mild, so that bamboos, hardy palms, 
oleanders, Gardenia and bananas grow freely in the open, and rice 
is the staple crop. 

The Japanese are world-famous as horticulturists, and their 
gardens are marvels of landscape art. The beauty of the flowering 
cherries and wistaria in the spring; the iris, lotus and morning 
glories of the summer; the exhibition of chrysanthemums in 
autumn have been the admiration of thousands of visitors to this 
beautiful land. 

Along the roadsides and about the temples and parks, the most 
abundant tree is a pine (P. densiflora), whose picture one sees in 
nearly every landscape adorning screen or fan. The Ginkgo, from 
China, already referred to, is often planted about the Japanese 
temples, where there are gigantic specimens many centuries old. 

To see the native vegetation in perfection one must visit the 
mountains, which are only thinly populated. Nikko, the famous 
resort some hundred miles from Tokyo, affords a convenient base 
from which to study the lower mountain vegetation. The magnifi- 
cent tombs and shrines for which Nikko is celebrated are in a 
grove of giant cedars (Cryptomeria) which strongly suggest the 
Californian redwoods. The rainfall is very heavy — about 150 
inches annually, and the region is heavily forested with mostly 
deciduous trees, and abounds in beautiful flowering shrubs and 
herbaceous plants. 

A walk through this forest to Chuzengi some 2,000 feet above 
Nikko, gives a good idea of the general character of the vegetation 
of this part of Japan. There are some evergreens, pines and firs, 
but deciduous trees predominate. Maples are especially abundant 
and beautiful, and beeches and oaks are common. Among the 
showy flowering shrubs and small trees, are dogwood (Benthamia), 



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THE NORTH TEMPERATE ZONE 83 

much like the American flowering dogwood, syringa (Philadelphia), 
Deutzia and Weigela. Above all are the azaleas which in the 
early summer are a blaze of scarlet and crimson. 

Between Chuzenji and Yumoto, between 4,000 and 5,000 feet 
elevation, are extensive grassy moorlands, which in midsummer 
are full of beautiful purple and white iris. 

The northern Island, Hokkaido, has a much colder climate, 
and the general character of the vegetation is astonishingly like 
that of the northeastern United States. Nearly all the trees, 
elms, oaks, maples, beeches, magnolias, and others, are very similar 
to American species, and this is true also of many shrubs and 
herbaceous plants, some of them being actually identical. Thus 
the poison ivy (Rhus toxicodendron) is very common and a wild 
grape (Vitis labrusca) is identical with the American fox-grape. 
The sensitive fern (Onoclea serisibilis), the maiden-hair fern, and 
the cinnamon fern, (Osmunda cimmmomea) are old acquaintances, 
and a long list of other familiar plants could be cited. In many 
cases, where species are not identical, the Japanese plant has a 
closely related species in America. Thus our trailing arbutus 
(Epigaea repens) has its counterpart in the Japanese E. Asiatica. 1 

Japan is rich in coniferous trees, most of which it shares with 
China. The hemlocks (Tsuga), Douglas fir (Pseudotsuga), and 
white cedar (Chamaecyparis) of the American forest, also have 
their representatives in Japan. 

Like the eastern American deciduous forests, those of Japan are 
magnificent in their autumnal dress. As in America, maples take 
first place in this display, but sumacs, Ampelopsis, ashes, oaks, 
elms, and beeches contribute their quota, while the evergreens 
form a background for the gayly colored deciduous trees. 

Siberia 

Conditions in eastern Siberia are not favorable for tree growth, 
and the trees are said to be much inferior to those in corresponding 
latitudes in America. In Kamtchatka and Sachalien, however, 
conditions are more favorable, and sometimes there is a good 
growth of forest. 

1 For a full discussion of the remarkable similarities between the vegetation of 
Japan and Atlantic North America sec Asa Gray's essay on the subject . Scientific 
Papers of Asa Gray, Vol. II, p. 125, 1889. 



CHAPTER IV 

THE NORTH TEMPERATE ZONE— (Continued) 

ATLANTIC AND CENTRAL UNITED STATES AND 

CANADA 

The temperate regions of North America are very extensive, 
comprising southern Canada, southeastern Alaska, and all the 
United States except southern Florida. 

This vast area is extremely diversified as to topography, and 
this together with great differences in climate, results in a very 
rich and varied flora. This territory lies, foi* the most part between 
latitude 50° and 30°, and extends from the Atlantic to the Pacific, 
a distance of over 3,000 miles. 

Nearly parallel with the Atlantic Coast is the Appalachian moun- 
tain system extending from Canada to Georgia. In its northern 
portion it approaches the coast, and the coastal belt is more or 
less broken by lower hills; but southward from New Jersey there 
is a more or less pronounced coastal plain which broadens toward 
the south and is coextensive with the flat lands of the northern 
shores of the Gulf of Mexico. 

The Appalachians are nowhere of great height, the loftiest 
peaks, like Mt. Washington in New Hampshire and Mt. Mitchell 
in North Carolina, being less than 7,000 feet elevation, and too 
low to possess a true alpine flora; nor are they of sufficient height 
to act as an efficient barrier between the coastal plain, and the 
regions to the west. 

Between the Appalachians and the Rocky mountains is the 
great plain drained by the Mississippi and its tributaries, and 
destitute of any mountain ranges of importance. To the north 
is the region of the Great Lakes, draining into the Atlantic through 
the St. Lawrence. 

This vast region has no barriers to plant migration, beyond cli- 
matic ones. From the Mississippi to the Atlantic coast is a region 
of ample rainfall, and the country originally was almost entirely 

84 



THE NORTH TEMPERATE ZONE 85 

covered with forest, in which deciduous trees predominated. Many 
of these, like the white and red oaks, elm, walnut, and others are 
found practically throughout this whole region. 

In the western sections of this area the rainfall is less, and there 
occur expanses of open grass-land or prairies, more or less inter- 
mingled with patches of forest. Still further west the true prairie 
formation prevails. 

In Canada and the northeast and central states, e. g., Michigan, 
Wisconsin and Minnesota, are regions of extensive glaciation, 
abounding in lakes and peat bogs. This is a transition region 
between the sub-arctic and the true temperate zone, and has many 
sub-arctic species, and the forest is composed to a considerable 
extent of conifers. 

West of the Mississippi is a region of treeless plains — prairies 
with close turf in the east, merging by degrees into the drier 
prairies and steppes of the regions adjoining the Rocky Moun- 
tains. Trees are for the most part confined to the banks of streams, 
or the bottoms of gullies worn down by the streams. 

The western third of North America is verv different from the 
east. It is a region of lofty mountains and elevated plateaus. 
The main range of the Rocky Mountains, extending from New 
Mexico into northwest Canada, has elevations of over 14,000 
feet, and between this and the great Pacific Cordillera are exten- 
sive elevated plateaus, and secondary mountain systems. Much 
of this plateau region is arid, and may be a true desert, as in the 
vicinity of the Great Salt Lake, and portions of Nevada and 
eastern Washington. 

Extending the whole length of the continent, parallel with the 
Pacific Coast, is the great Cordillera which with few breaks, 
stretches from Alaska to Patagonia, and sharply sets off the coastal 
region of the Pacific from the rest of the continent. 

The whole of the great mountain region from the Rockies to 
the Pacific, is very different climatically and floristically from 
Atlantic North America, and here alone are the mountains high 
enough to have perpetual snow, and to develop a true alpine 
flora. Especially on the majestic snow-clad cones of the great 
volcanic peaks, Shasta, Hood, Tacoma, are these conditions 
especially favorable. 

In southern California, Arizona and New Mexico, there are 



86 OUTLINE OF PLANT GEOGRAPHY 

extensive steppes or deserts, really part of the great Mexican 
plateau, and in climate and vegetation perhaps rather sub-tropical 
than temperate. 

As a whole the climate of temperate North America is decidedly 
continental in character, the range of temperature being large, 
especially in the dry plains of the interior. In Montana, the follow- 
ing extreme temperatures have been recorded, 1 viz: — 65° and 
117° F., a range of 182°! 

The temperature of the sea-board, both Atlantic and Pacific, 
is naturally influenced by the proximity of the ocean, but this is 
much more marked on the Pacific coast, where the prevailing 
westerly winds traverse the ocean, whose temperature varies but 
little, and the high mountains to the east protect the coastal belt 
from the effects of extreme temperature changes of the interior 
regions. 

The whole Pacific coast has a remarkably equable climate, mild 
winters and cool summers. The January isotherm of 0°C, which 
on the Atlantic coast is in the neighborhood of New York and 
Philadelphia, (lat. 40°), on the Pacific is pushed north as far as 
Sitka, in Alaska (lat. 58°). In San Francisco there is only a differ- 
ence cf ten degrees Fahrenheit, between the coldest and warmest 
months (50°-60°) ; in Washington, nearly in the same latitude, 
the difference is more than four times as great (32°-78°). The 
differences are even greater in the interior of the country. 

In general, the climate of the eastern third of the LTnited States 
is one of hot humid summers and cold winters. Except for a small 
part of southern Florida, no part of the eastern states is immune 
from occasional killing frosts; while over the greater part of the 
area the winter is a season of absolute cessation of all plant ac- 
tivity, and in the interior more than half the year is a dead season 
for pretty much all vegetation. 

In the northern tier of states vegetation rarely starts before 
April, of course becoming earlier as one proceeds southward, and 
the coastal region has a decidedly earlier spring and more pro- 
tracted autumn than inland stations in the same latitude. 

At the south, spring is somewhat gradual, but toward the north 
the transition from winter to summer is much more abrupt, and 

1 Kirkwood, J. E., Forest Distribution in the Northern Rocky Mountains, Univer- 
sity of Montana Studies, p. 49, 1922. 



THE NORTH TEMPERATE ZONE 87 

the foliage of the deciduous trees seems to expand almost over 
night. Where the deciduous forest prevails, the spring is marked 
by a profusion of delicate herbaceous perennials, such as violets, 
spring-beauty, blood-root, anemones, etc., which spring up very 
quickly and flower before the leaves of the trees expand. They 
soon mature their fruit, and in a few weeks have mostly disap- 
peared, remaining dormant until the next spring. 

A feature of these deciduous forests is the magnificent display 
in the autumn when the varied species show a wonderful variety 
of brilliant colors in the ripening foliage. The gorgeous dyes of 
the sugar and scarlet maples; the crimson, purple and scarlet of 
the gums; the gold, russet and wine reds of the oaks, hickories, 
dogwoods and ash, and the blood-red sumacs, huckleberries, and 
many other shrubs, combine to make an unrivalled display of 
splendid color. 

While temperature is a very important factor in plant distri- 
bution, moisture is perhaps even more so. The whole eastern 
United States is a well watered country, abundantly blessed with 
great rivers and lakes, and consequently having an ample rainfall. 
The precipitation is heaviest in the southern coastal regions and 
the slopes of the southern mountains; but throughout the region 
east of the Mississippi there is a rainfall of 30-60 inches, and 
nearly the whole country was covered originally with heavy 
forest. 

Westward the precipitation falls off materially, and this com- 
bined with a much higher evaporation, results in conditions un- 
favorable for tree growth ; and these conditions become still more 
marked in the elevated plains adjacent to the Rocky Mountains. 
In the cooler northern regions of Montana and Western Canada, 
the prairie reaches to the foot of the mountains; further south the 
western plains are arid, and may be described as steppes, rather 
than true prairie. 

The absence of any mountains between the Rockies and the 
Appalachians, exposes all of the eastern United States to the great 
air movements originating in the Canadian Northwest. The 
effect of the "cold waves," starting in the far northwest, are felt 
as far south as the Gulf States. 

Topography plays a minor role in the climate of eastern North 
America, the two most important factors being latitude, and 



SS OUTLINE OF PLANT GEOGRAPHY 

proximity to the coast, or the effects of large inland bodies of water 
like the Great Lakes. 

In the western mountain area, however, topography exercises 
a very great effect on the climate, largely controlling both tempera- 
ture and precipitation. The direction of the mountain ranges, 
as well as their height, strongly influences the amount of precip- 
itation, and also the temperatures of the adjacent regions. This 
is very plainly shown in many places on the Pacific Coast, Where 
the mountain ranges are parallel with the coast, as in central 
California, the moisture is mainly precipitated on the windward 
(west) side, and inland the climate is much drier. This difference 
in the rainfall within a short distance may be very great. Thus 
in the canyons of the Santa Cruz mountains within 25 miles or 
less of Stanford University, the rainfall may average more than 
60 inches annually, and a forest of giant redwoods clothes the 
mountain sides; while at the University, in the valley to the east 
of the mountains, the rainfall rarely reaches 20 inches, and the 
open valley supports only scattered tree growth. 

The inland valleys, too, shut off from the cool ocean breezes, 
have very high temperatures compared with the cool coastal sum- 
mer climate. While San Francisco during July and August rarely 
sees the thermometer reach 70°, the inland cities like Fresno may 
have maxima exceeding 110°. 

Eastern United States and Canada 

As in the Eurasian continent, there is not a very clear line of 
demarcation between the sub-arctic zone and the north temperate. 

Along the Atlantic coast temperate conditions prevail as far 
north as New Brunswick and Nova Scotia, which in the parts 
adjacent to the sea enjoy a much milder climate than prevails 
elsewhere in eastern Canada, and a number of plants are found 
here which are not met with again until the coast of New Jersey 
is reached. It has been thought l that they are relics of an ancient 
coastal flora which once occupied the now submerged continental 
shelf. Perhaps the most interesting of these is a small fern, 
Schizaea pusilla, the only representative in the United States of a 

1 Fernald, M. L., "The Gray Herbarium Expedition to Nova Scotia," Rhodora, 
Vol. XXIII, May, 1921. 



THE NORTH TEMTERATK ZONE 89 

genus mainly confined to the tropics and to the temperate regions 

of the southern hemisphere. 

The forests of New Brunswick and Nova Scotia 1 are of two 
types, one in which conifers predominate, and which approaches 
the sub-arctic forest, the other mainly composed of deciduous 
species. The latter occupies the best soils, and its most abundant 
trees are sugar maple and paper birch, with an admixture of red 
spruce and balsam fir, with occasionally white pine. In some areas 
beeches are the prevailing trees. 

Recently, attention has been called to the occurrence in certain 
isolated areas in eastern Canada of many plants unknown else- 
where in eastern America, but which are identical with or closely 
related to species of the Rocky Mountains and Pacific Coast. 
These western species are especially abundant in the Gaspe 
Peninsula at the mouth of the St. Lawrence, and on the Long 
Range in Western Newfoundland. 

Fernald 2 has shown that the areas occupied b}^ these far- 
western plants have apparently entirely escaped glaciation and 
that these plants are probably relics of wide-spread pre-glacial 
species which were destroyed elsewhere in eastern America by 
the great ice-sheet which covered the rest of the country. 

Throughout northern New England, e. g., Maine, Northern 
Vermont, and New Hampshire, the forest is much the same as 
in New Brunswick. Red spruce is the most abundant species, 
together with white pine and balsam fir. Beech and sugar maple 
also occur, but less abundantly than the conifers. In the more 
southerly areas of the coniferous forest, black spruce is more 
abundant, and white cedar {Thuja occidental is) and hemlock occur, 
as well as various deciduous trees. 

The conifers are more abundant at higher elevations, while 
at the base of the mountains, especially in the better soils, de- 
ciduous trees become dominant, and there is a transition to the 
hard-wood forests characteristic of southern New England. Sugar 
maple, beech, and yellow birch (Betula Ivied) are the commonest 
trees, but oaks, elms, and other common New England species 
begin to appear. 

1 HarshberKor, J. W. f Phytngcogrnphic Survey of North America. Die Vbgata- 
tion der Erde, XIII, pp. .)<» 1-370, 1911. 

2 Fernald M. L., Persistence of Plants in Ungladated Arms of />'"/•<.// North 
America, Mem. Amer. Acad, of Arts and Science, Vol. XV, No. Ill, 11)25. 



90 



OUTLINE OF PLANT GEOGRAPHY 



The northern Maine coast and the adjacent islands have a 
distinctly northern, almost sub-arctic flora, the forest being pre- 
dominantly coniferous with a small admixture of such deciduous 
trees as birches and poplars, and an undergrowth of such 

boreal plants as Linnaea, dwarf 
cornel (Cornus Canadensis), 
gold-thread (Coptis), and bush 
maples. 

The coast is a very rugged 
one, with rocky headlands and 
reefs, sand dunes and extensive 
beaches, and in places with 
sandy moorlands and swamps. 
In the low forest near the coast 
in Massachusetts, pitch pine 
(Pinus rigida) is common, and 
red cedar (Juniper us Virgin- 
iana), with oaks, maples, and 
other deciduous trees. 

The sandy moorlands harbor 
many interesting and beautiful 
plants. On Nantucket Island 
where this moorland is devel- 
oped on a large scale three 
species of heaths are found, 
the common heather (Calluna 
vulgaris) and two species of true 
heaths (Erica), the latter un- 
known elsewhere in America, and perhaps introduced from Europe. 
Characteristic plants of the moors and forest belt of the New 
England coast, are several others of the heath family, e. g., bear- 
berry (Arctostaphyios uva-ursi), Kalmia, huckleberries, trail- 
ing arbutus (Epigaea repens), Azalea and wintergreen (Gaul- 
theria procumbens) . Roses, huckleberries, wax-berry (Myrica 
Carolinensis), wild plums and cherries, service-berry (Ame- 
lanchier) Spiraea, and sumac, are among the common shrubs 
of the New England coast. In some of the swamps north of 
Boston, the sweet-bay (Magnolia glauca) occurs, its northern 
limit. A number of beautiful orchids, as well as many other 




Fig. 17. — Arbor vitae swamp, Douglas 
Lake, Michigan. Photo., Dr. F. C. Gates. 



THE NORTH TEMPERATE ZONE 91 

showy herbaceous flowers occur in this district. Of the orchids, the 
most beautiful is the pink lady's slipper, or " moccasin-flower, ' 
Cypripedium acaule. 

The northern Xew England coast, owing to its rocky forma- 
tions, and great differences in tide levels, offers exceptional 
opportunities for the study of the rich marine flora, much of 
which is exposed at low tide. The vertical rock faces show an 
interesting succession of forms, the light green sea-lettuce (Ulva), 
appearing near the high tide mark; below this, but exposed 
for much of the time are several bladder kelps (Fucus spp.) and 
the curious Ascophyllum nodosum, whose long whip-like fronds 
form a dense curtain along the base of the rocks, and parti} 
conceal the bladder kelps. With these large sea-weeds are asso- 
ciated many smaller species of red and brown algae. 

Below the low-water mark is a region with a great develop- 
ment of the large kelps, Laminariaceae, in which several species 
of Laminaria predominate. Other characteristic species are 
Alaria esculenta and Agarum Turneri. The more delicate red 
algae are found mostly at still greater depths. 1 

Throughout most of New England the American elm (Ulmus 
Americana), is a very characteristic tree, reaching perhaps its 
finest development in the Connecticut valley. Red and white 
oaks, white pine, walnut and hickory are abundant, and until 
it was completely exterminated by the blight, the chestnut 
(Castanea dentata) was one of the commonest trees of New Eng- 
land. 

In southern Connecticut, near the shores of Long Island Sound, 
the tulip-tree and sweet gum (Liquidambar) are found, but these 
trees belong more to the regions further south. 

From the St. Lawrence to the Lower Lakes, including western 
New York, southern Michigan and Ontario, is a forest region 
which has few or no coniferous trees throughout much of its 
extent, although in some districts hemlock and white pine occur. 
Further north, in northern Michigan, Wisconsin and Minnesota 
the forest is predominantly coniferous, but there is a consider- 
able mixture of deciduous trees. The most important tree of 
this northern forest is the white pine (Pinus slrobits), which 
has been largely exterminated by the lumberman. The white 

1 For a fuller account of these algae, see Harshberger, loc. cit., pp. 383-1. 



92 



OUTLINE OF PLANT GEOGRAPHY 



pine was dominant on gravelly and rocky soils, but also occurred 
in the mixed forest. Where are good, well drained soils, bass- 
wood, sugar maple, beech, elm, and canoe-birch are character- 
istic trees, with which are associated white pine, hemlock, spruce 
and balsam. The wetter areas may be swamps with a dense 
growth of tamarack {Larix Americana) or white cedar {Thuja 
occiderdalis). In the drier soils, about the southern margin of 









Fig. 18.- 



- American elm {Ulmus Americana), banks of Unadilla River, New York. 

Photo., E. L. Crandall. 



Lake Superior, the Norway pine (P. resinosa) is a common and 
picturesque tree. 

In Michigan the mixed forest of the north passes into sandy 
barrens in which the Jack-pine (P. Banksiana), predominates, 
but there are also open groves of oaks, "oak openings," with 
stretches of intervening grass-lands, or small prairies. The 
latter formation is well shown in southwestern Michigan. 

The forest of southeastern Michigan is a deciduous one, made 
up of much the same trees as that of New England. 

In the neighborhood of Detroit, in clay soils, the commonest 
tree is probably the American elm; but sugar, silver, and red 
maples, walnut, hickory, ash, and several oaks, are also char- 



THE NORTH TEMPERATE ZONE 93 

acteristic. In lighter soils, beeches, sassafras and pepperidge 
(Nyssa ) and occasionally chestnut, may also be noted. Less 
abundant are hackberry (Celtis), honey-locust (Gleditschia), and 

of the smaller trees and large shrubs, are several species of thorns 
(Crataegus), the flowering dogwood, crab-apple (Mains coronaria), 
wild plums and cherries. The only conifer is a small cedar (Juni- 
perus) occasionally seen on the banks of the Detroit river. 

West of the Great Lakes, in Illinois, Wisconsin and Minne- 
sota, this type of forest occurs, but much diminished in extent, 
and in the number of species. Its western limit has been placed 
at the valley of the Red River of the North, and marks the west- 
ward and northward limits of a good many tree-species. 

Woody climbers are not especially abundant in this forest, 
but wild grapes of several species sometimes attain a great size, 
and the Virginia creeper and poison ivy (Rhus toxicodendron), 
may climb high up into the trees. Less conspicuous are the 
bittersweet (Cclastrus scandens), moon-seed (Menispermum Cana- 
dense), Clematis, and several species of Smilax. 

Many showy shrubs form the undergrowth of the more open 
forest, or along its edges. Elder, Viburnum, Spiraea, raspberries 
and blackberries, currants and gooseberries, roses and others 
are represented by several species, and the woods, fields and 
marshes show a wealth of beautiful herbaceous plants. 

In the early spring, before the leaves of the trees unfold, many 
delicate and beautiful herbaceous plants cover the floor of the 
forest with a carpet of dainty bloom. Spring-beauty (Claytonia), 
blood-root (Sanguinaria), Dicentra, adder-tongue (Erythronium), 
cress (Cardamine, Dentaria), Hepatica, Anemone, buttercups, 
Trillium, crane's bill (Geranium), Phlox, violets, mandrake (Podo- 
phyllum), are a few of these woodland flowers. 

Somewhat later, in the more open places, masses of blue lupins 
(Lupinus perennis), pink phlox, orange milkweed, shooting stars 
(Dodecatheon), tiger lilies, continue the floral display, and still 
later the host of showy Com posit ae, sunflowers, Rudbeckia, Eupa- 
torium, asters and golden-rods, etc., offer the most brilliant floral 
display of the year. 

The lower lake region is characterized by extensive marshes 
along the shallower shores of the lakes and the connecting rivers. 
These are developed on a large scale along the Detroit River, and 



94 



OUTLINE OF PLANT GEOGRAPHY 



the small streams emptying into it. The marshes have a rich and 
very interesting vegetation. Great beds of rushes (Scirpus) and 
cat-tails (Typha), and many species of sedges and grasses, among 
the latter the wild rice (Zizania aquatica) which in the late summer 
is very conspicuous with its graceful plumes. The open spaces of 
the marsh harbor a rich assortment of algae, stone-worts (Cha- 
raceae), and many pond weeds (Potomogeton, Vallisneria, Elodea, 




Fig. 19.— Small glacial lake, Cheboygan County, Michigan. Photo., Dr. F. C. Gates. 

etc.), while beds of white and yellow water-lilies, and occasionally 
the great yellow lotus (Nelumbo), cover the surface of the water 
with their big leaves and showy flowers; and white arrow-head 
(Sagittaria) and blue pickerel-weed (Pontederia), abound about 
the margins of the shallow water. 

Many showy herbaceous plants and shrubs grow around the 
edge of the marsh and advancing from year to year on the soil 
built up by the silt and their own decaying tissues, sometimes 
extend the land into the marsh with surprising rapidity. Elder, 
willows, button bush (Cephalanthus), wild roses, are among the 
common members of this community, and with these are such 
herbaceous plants, as the pink milkweed, purple Eupatorium, 
loosestrife (Lythrum), horse mint (Monarda), asters, golden-rods, 
thistles and many others. 



THE NORTH TEMPERATE ZONE 



95 



Occasionally the big pink hollyhock flowers of the marsh mallow 
(Hibiscus moscheutos) are seen, a flower belonging properly to the 
salt marshes of the Jersey coast. Among the maritime plants that 
have made their way to the shores of the Great Lakes, are the sea- 
rocket (Cakile maritima) and the beach pea (Lathijrus maritimus). 

The northern forest area abounds in glacial lakes of all sizes. 
The smaller lakes and ponds sometimes have been completely 




Fig. 20. — Deciduous forest, early spring, Rock Creek Park, Washington, D. C. 
Oaks predominant; red-bud (Cercis Canadensis), and flowering dogwood, as 
undergrowth. 

filled by the invasion of peat mosses (Sphagnum), and other bog 
plants, and form swamps of greater or less extent, in which white 
cedar or tamarack often form dense growths. These bogs arc the 
home of many very beautiful plants, some of the finest orchids, 
like the great pink lady's slipper (Cypripedium spectabilc) and the 
exquisite Arethusa, Pogonia and Calopogon. Cranberries, An- 
dromeda and other heath-like plants inhabit these bogs, as well as 



96 OUTLINE OF PLANT GEOGRAPHY 

the curious insectivorous sundews (Drosera) and pitcher plant 
(Sarracenia). With the reclamation of these swamplands, many 
of the choicest North American plants must disappear. 

Eastward of the Mississippi, between 30° and 40° latitude, 
is the richest forest of temperate North America, and origi- 
nally this region was almost entirely an unbroken forest, com- 
posed mostly of a great variety of deciduous trees. Along 
the east coast from New Jersey to Florida and also along the 
northern shore of the Gulf of Mexico is the coastal plain, in which 
are extensive pine-barrens occupying the sandy soils. Pines of 
several species are the predominant trees. Except for these 
coniferous forests, and those of the higher altitudes of the Appala- 
chians, the forest of the eastern United States is made up mostly 
of deciduous species. This forest reaches its finest development 
on the lower slopes of the southern Appalachians in North Carolina 
and Tennessee, and in the rich river valleys of the Ohio and the 
lower Mississippi. Oaks of many species and often trees of great 
size are conspicuous, including the white, red, and scarlet oaks, 
as well as many other less familiar species. Ashes, elms, chestnut, 
several birches, maples, beech and bass-wood, are the same as 
those of the more northern forest area; but in addition to these, 
all of which are represented in the European forests by related 
species, there are a number of characteristic extra-European 
genera, most of which have allies in eastern Asia. First in impor- 
tance is the tulip-tree, Liriodendron tidipifera, probably the tallest 
deciduous tree of the American forest, sometimes being nearly 
200 feet in height, and with a straight lofty trunk which is said 
to occasionally be nearly ten feet in diameter. From New York 
southward, the sweet gum (Liquidambar sty rati flua) is a common 
and very beautiful tree of large size, especially in rich alluvial 
soils. Pepperidge (Nyssa), persimmon (Diospyros) and sassafras 
are also characteristic, and in the southern areas the common locust 
(Robinia pseudacacia) as well as several other species occur. The 
sycamore (Platanus octidentalis) , which is common throughout 
the eastern states, along streams, is one of the largest of American 
trees. 

Among the most striking of the trees of the middle and southern 
states are several species of Magnolia. The great evergreen mag- 
nolia (M. grandi flora), is decidedly a southern tree, but two species, 



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98 OUTLINE OF PLANT GEOGRAPHY 

the cucumber tree (M. acuminata) and sweet bay (M. glauca) 
of the coastal swamps, extend as far north as New York. The 
southern species, like M. grandiflora and M. macrophylla, are 
very tropical looking with their big leaves and giant flowers. 

The larger trees form a close forest with a dense canopy of 
foliage during the summer months. Below this upper tier of 
trees are a number of smaller trees and shrubs which can thrive 
in the shade of the larger trees. Among these are the flowering 
dogwood (Cornus florida), red-bud (Cercis Canadensis), witch 
hazel (Hamamelis Yirginica), species of Viburnum, Euonymus, 
Azalea, and others. In more open localities, as about the margin 
of the forest, or in clearings, are many species of thorns (Cratae- 
gus) a genus which is extraordinarily developed in eastern America. 

Crab-apples, wild plums and cherries, roses, spiraea, brambles, 
currants and goose-berries, honeysuckle, sumac of several species, 
are a few of the shrubs wide-spread throughout the whole area. 

This magnificent mixed forest may be seen in great perfection 
in the southern Appalachian region. The variety of trees is very 
great, and the trees are tall and symmetrical. There is a small 
admixture of conifers, white pine and hemlock being common in 
places. 

A feature of this region is the remarkable development of showy 
Ericaceae. Even as far north as New England, the beautiful 
mountain laurel (Kalmia latifolia) is common, and in its southern 
range it may become a small tree. The great rhododendron (R. 
maximum), also reaches New England, but is much more abundant 
further south. Few floral displays can equal the North Carolina 
mountains in May and June, when the thickets of laurel are 
covered with rosy bloom, and the flame-azalea lights up the moun- 
tain side with masses of orange and crimson. The big rhododen- 
dron is very common, and on the higher mountains are extensive 
thickets of the splendid purple R. Catawbiense, a gorgeous sight 
when in flower. Another characteristic member of the same family 
is the sorrel tree (Oxydendron). 

The young foliage of the deciduous forest exhibits a great variety 
of color. The unfolding oak leaves show exquisite tints of pink, 
gold and pale green, contrasting with the vivid red of the scarlet 
maple, and bright green of the tulip-tree. The effect is as varied 
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100 OUTLINE OF PLANT GEOGRAPHY 

same forests a blaze of color in the autumn. Where the snowy 
flowers of the dogwood, and the rosy pink of the red-bud light up 
the forest just as the leaves begin to unfold, the picture is complete. 

South of the Carolinas and Tennessee the forests begin to assume 
a more tropical aspect, with an infusion of broad-leaved ever- 
greens, like magnolia, live oaks, holly and laurel (Persea), and 
in the coastal region, palmettos, the northernmost representatives 
of the tropical family of palms. 

There is a decided increase, too, in the number of woody 
climbers or lianas; Bignonia, trumpet creeper (Tecoma), Wis- 
taria, yellow jasmine (Gelsemium) passion flowers and some 
others, are added to the grapes, Clematis, Virginia creeper, and 
other northern climbers. 

The Coastal Plain 

Eastward from the Appalachian mountain system, from New 
Jersey southward, is the Atlantic coastal plain, narrow in its 
northern portion, but widening at the south, and becoming very 
broad in the Carolinas and Georgia, where it passes into the 
coastal region of the Gulf of Mexico. This whole region is geologi- 
cally comparatively recent, and much of it raised but little above 
sea-level. 

North of Chesapeake Bay, it is a narrow, more or less interrupted 
strip of barren strand. A few plants, such as the dwarf prickly- 
pear, characteristic of this region, occur at points further north, 
as in Nantucket and Martha's Vineyard, and relics of this coastal 
flora are also found in New Brunswick and Nova Scotia, indicat- 
ing a former connection with the coastal plain further south, 
severed by the subsidence of the continental shelf. 

The extensive beaches of Long Island and New Jersey belong 
to this formation and support a characteristic strand flora, much 
like that found along the Massachusetts coast in similar locali- 
ties, such as huckleberries, wax-myrtles and others, and the stunted 
trees are also many of the same species. In places the drifting 
sand is gradually burying the forest on the land side. 1 

The Jersey pine-barrens have been very thoroughly studied. 
The pitch pine (Pinus rigida) is the predominant species, and 

1 Harshbergcr, loc. cit., pp. 413-423. 



THE NORTH TEMPERATE ZONE 101 

covers large areas, in an open formation, associated with scrub- 
oaks of several species together with such shrubs, as huckle- 
berries, Andromeda, Azalea, Leucothoe, bear-berry and trailing 
arbutus, all members of the heath family, as well as many other-, 
among them the sweet fern (Comptonia) and many herbaceous 
plant-, some of which are almost entirely confined to it. 

Cedar swamps in which southern white cedar (Chamaeeyparis 
ihuyoieles) is predominant, are a common feature of the region, 
and harbor many rare and interesting plants. Of the small tr- 
and shrubs may be mentioned red maple, Magnolia glauca, Aza- 
lea viscosa, black alder (Ilex vertieillata) and the fragrant white 
alder (Clethra aim folia). 

The rare fern Schizaea pusilla, occurs in this region, and cran- 
berries, sundews and pitcher plants abound in the bogs, as well 
as the royal fern (Osmunda regalis) and cinnamon fern (0. cin- 
namomea). 

The whole coast south of Xew Jersey is destitute of rocky for- 
mations, and the conditions are much less favorable to the growth 
of algae than along the rocky Xew England shore. The water 
is much warmer, and the algae are often of tropical or sub-tropical 
types, e. g., Dictyota, Padina, Sargassum, etc. Marshes abound 
along the tidal rivers, with a mixture of fresh and salt water types 
of vegetation. 

From Virginia southward, the northern pitch pine is replaced 
by other species, Pinus taeda being the common species in Vir- 
ginia. While the vegetation of the pine-barrens, is on the whole 
much the same as in Xew Jersey, distinctly southern species 
become increasingly abundant; locust, trumpet creeper (Tecom 
yellow jasmine (Gelsemium), occur in Virginia, and in North 
Carolina the southern elements become still more conspicuous. 
Among the characteristic species is the red bay \Persea borbonia) 
belonging to the laurel family; live oaks and dwarf palmettos, 
and in South Carolina the tall palmetto (Sabal palmetto) are com- 
mon. A famous denizen of the pine-barrens of the Carolinas, is 
the remarkable Venus's flytrap (Dionaea muscipulei) unknown 
elsewhere. In this same region are also several species of pitcher 
plant- Sarracenia). 

The pine forests of Virginia and the Carolinas are very extensive 
and reach far inland, and are of great value. Near Washington 



102 



OUTLINE OF PLANT GEOGRAPHY 



the common species is P. rigida, further south the long-leaved 
pine, P. palustris, occurs, but P. taeda and P. rigida, occur through- 
out the region. These pine forests may have no other trees, 
or there may be an undergrowth of smaller trees, especially 
oaks. 

In South Carolina, as in Florida, there are level sandy stretches 
of great extent, with a dense growth of the dwarf saw-palmetto 
(Serenoa serruiata) interspersed with stunted pines, including the 




—Cypress swamp, Wakulla Springs, Florida. Taxodium distich um, with 
Tillandsia. Photo., Professor H. Kurz. 

West Indian P. Caribaea. In Georgia are extensive pure stands of 
the long-leaved pine (Pinus palustris), highly prized for its timber. 
In the wet districts are often extensive " cane-brakes," in which 
the principal element is the reed-grass, Ariindinaria macro sperma. 
The coastal plain of the Gulf States much resembles the southern 
Atlantic coast and the long-leaved pine is the prevailing species. 
This formation reaches its western limit in Texas, and part of it 
may be seen along the Southern Pacific railway, before reaching 
the swamp-lands near New Orleans. 

As one passes from the dr} r prairies of the interior of Texas, 



THE NORTH TEMPERATE ZONE 103 

scattered pines begin to appear and finally form an open forest. 
This gradually is replaced by a mixed hard-wood forest as the 
moister coastal region is approached, and cypress swamps become 
frequent, in which one sees the fantastic cypresses bearded with 
the " Spanish moss" (Tillandsia). 

These cypress swamps are among the most striking plant as- 
sociations of the country. They occur as far north as Virginia, 
near the coast, and extend up the Mississippi Valley into southern 
Missouri and Illinois. 

The bald cypress (Taxodium distichwn), is a large tree, often 
growing permanently in water, but also in rich moist ground which 
is not submerged. Where the base of the trunk is submerged, 
there are developed on the roots, the " knees," conical outgrowths 
which appear above the water, and serve for aerating the roots. 
The young trees are very symmetrical in form, like most conifers, 
but the older trees develop a very irregular and fantastically 
branched crown rising above the other trees of the association. 
In the wetter portions of the cypress association the principal 
species are the sour gum (Nyssa aquatica) and an ash (Fraxinus 
platycarpa), but oaks, maples, hickories, and some others also 
occur. 

In the Gulf region, dense growths of the dwarf palmetto (Sabal 
Adansonii) are common, and the branches of the cypress are 
heavily draped with the dismal blackish streamers of Tillandsia. 

About the margins of the swamp are some showy herbaceous 
aquatics. Passing through this region in early April, the writer 
noted two handsome species of Iris (I. hexagona, and /. cuprea), 
a white spider-lily (Hymenocallis), showy species of Phlox, Sen- 
ecio, Oenothera and Lobelia, and magnificent masses of the royal 
fern (Osmunda regalis) as well as several other ferns. 

In the river valleys of eastern Texas there is a hard-wood forest, 
which in places is dense and with trees of large size; but westward 
with the lessening rainfall, the forest disappears and the prairie 
becomes dominant. Eastern Texas marks the westward limit 
of the southern deciduous forest as well as the pine forest of the 
coastal plain. 

The transition from the heavily wooded eastern states, to the 
prairie states along and beyond the Mississippi, is a gradual one. 
In southeastern Michigan, northwest Indiana, and much of Illi- 



104 



OUTLINE OF PLANT GEOGRAPHY 




Fig. 22.— Alluvial swamp, about six miles west of Tuscaloosa, Alabama. 

Dr. R. M. Harper. 



Photo., 



THE NORTH TEMPERATE ZONE 



105 



nois, there is a mingling of forest and prairie floras. In alluvial 
soils there may be a well developed forest of the usual type, but 
with fewer species than further east. In the lighter soils, forests 
when present are much more open, and the predominant trees 
are oaks of relatively small size. These "oak openings'' are 
familiar features of the transition regions of northern Illinois 
and Wisconsin. In the sandy soil at the foot of Lake Michigan, 
there are white pines growing on the dunes, among the oaks, and 
in the lower ground the pepperidge (Nyssa sylvatica), is also a 




Fig. 23. — Woodland and prairie near Chicago; Sumac invading grass-land. Photo., 

Dr. A. G. Vestal. 

feature of the formation. For the most part, however, the forest 
is a strictly deciduous one. With the oaks there are sometimes 
hickories amd walnuts. The trees of the oak openings are rather 
scattered with thin under-growth, except for grasses, and a variety 
of other herbaceous plants. 

The soil of the typical oak openings is usually a sandy one, and 
not favorable for the growth of moisture-loving plants. Where 
there has been a sufficient accumulation of humus, a few woodland 
species become established, but they are few in number of species, 
and less luxuriant than those of the typical deciduous forest. 



106 OUTLINE OF PLANT GEOGRAPHY 

The following species of oaks occur in the oak openings, viz., 
Quercus alba, Q. rubra, Q. coccinea, Q. velutina, Q. macrocarpa, 
and Q. Maryland ica. The common hickory is Carya microcarpa. 

The forest of the northern transition region according to Harsh- 
berger l is of three kinds. On the ridges and hill-slopes oaks are 
the predominant trees, but with these are associated hickories 
(Carya alba), aspens, cotton- woods, ash (Fraxinus sambucifolia) , 
hornbeams (Ostrya, Carpinus), canoe-birch, butternut (Juglans 
cinerea), and occasionally bass-wood (Tilia Americana). In the 
moister alluvial soils the silver maple, green ash, elm, bass-wood, 
black walnut, hickory and cotton-wood are found. 

At the northern limit of the region, there are sandy areas where 
the white pine and yew occur, with birches and alders, this forma- 
tion being decidedly boreal in character. 

Further south, in Iowa, there occur in the alluvial formations 
a number of more southern species, like the honey-locust (Gle- 
ditschia), Sycamore (Platanus occidentalis) , and mulberry (Morns 
rubra). 

The grass-lands become more and more predominant westward, 
until the unbroken prairie is reached, which at the north extends 
unbroken to the foot of the Rockies. 

Toward the south the grass-lands are less extensive, and in 
western Kansas and Nebraska the region is rather a dry steppe, 
than true prairie, and this is still more marked in western Texas 
and New Mexico, where the country is an arid steppe or desert, a 
northward extension of the dry plateau of Mexico. 

With the diminution in rainfall toward the west, and the in- 
creased elevation, the close sod of the eastern prairie is replaced 
by an open formation of bunch grasses, among which occur many 
species of plants like the yuccas, and occasional cacti, characteris- 
tic of the arid regions further south. 

The eastern prairie region has a fair rainfall, and the absence 
of trees has been the subject of some speculation, as conditions 
would seem to be favorable for their growth. 2 It has been con- 
jectured that the prairies owe their origin to the burning of the 
forests by the Indians to furnish feed for the herds of buffalo, but 
the latter themselves may very well have played an important 

1 Loc. cit., p. 521. 

2 Haishberger discusses this question st some length, see loc. cit., p. 516. 



THE NORTH TEMPERATE ZONE 



107 



role in the destruction, by close cropping of any young trees that 
may have attempted to get a foot-hold. Once established, how- 
ever, the dense mat of grass offers very little opportunity for the 
growth of seedling trees. 

Further west, the extreme weather conditions, dry and cold, 
are sufficient to account for the absence of tree growth on the 
western plains, which naturally would assume their present con- 
dition of arid prairie or steppe. 

A study of the wet prairie near Chicago x indicates that it was 



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originally a swamp. While grasses are the predominant plants 
of this prairie, they are associated with a number of other char- 
acteristic forms, some of which have very attractive flowers. 
Where there are remnants of the original vegetation, as along the 
railway in places, one may see in spring, even near Chicago, masses 
of pink phlox, shooting star (Dodecatheon), the beautiful bird's- 
foot violets (Viola pedata), and the big leaves of the rosin-weed 
(Silphium), which later sends up its tall stems bearing big sun- 
flower like blooms. In the late summer and autumn, golden-rods 
and asters abound, and the pink blazing-star (Liatris) is also 

1 Cowles, H. C., Bot. Gazette, XXXI, p. 145, 1901. 



108 OUTLINE OF PLANT GEOGRAPHY 

common, as well as a number of Leguminosae, e. g., Amorpha can- 
escens, Baptisia, Mclilotus. 

The prairie reaches its most typical development in western 
Iowa, eastern Kansas and Nebraska, 1 and the Dakotas. The 
grass flora comprises over 30 species, but there are many other 
herbaceous plants, of which the most abundant are various Com- 
positae, sun-flowers, Coreopsis, iron-weed (Vemonia), asters and 
golden rods, worm- wood (Artemisia), and others. Anemones, 
larkspurs, phlox, verbena, oxalis, flax, blue-eyed grass (Sisyrinch- 
ium), milkweeds (Asclepias), are characteristic, as well as others 
including several genera of Leguminosae, e. g., Desmodium, As- 
tragalus, Baptisia. 

The only woody plants belonging properly to the prairie of 
this region are a dwarf willow (Salix humilis) and a rose {Rosa 
Arkansana). 

Along the streams, willows and cotton- woods are found, but 
these do not invade the prairie. Of course much of the original 
prairie has been broken up, and is now covered with the great 
wheat and corn fields of the midwest. 

The constitution of the prairie of Nebraska has been very 
thoroughly studied. 2 There are two types, depending on soil 
conditions. On loamy soils there is a close sod composed of 
several species of grasses, e. g., Sporobolus, Koeleria, Eatonia, 
Panicum; on heavy clay is the buffalo-grass formation, where 
" bunch grasses" form separate mats or large tufts, with bare 
ground between. The most important of the bunch grasses are 
the buffalo-grass (Buchloe dachjloides) and " grama-grass " (Bout- 
eloa oligostachya). Buffalo-grass formation is typical of most of 
the western cattle ranges. 

A good many secondary species of grasses, as well as various 
other plants may occupy the space between the prevailing bunch 
grasses. One of the common grasses, Stipa comata, at once at- 
tracts attention by its conspicuous silvery plumes. Occasionally 
a small yucca or cactus suggests the still drier plains further west. 

Toward the north the true prairie reaches to the foot of the 
mountains which rise abruptly from the rolling prairie. This is 

1 Pound, Roscoe and Clements, F. E., Botanical Gazette, XXV, p. 384, 1898. 

2 Harshberger, loc. cit., p. 526. See also Woodard, J., in Botanical Gazette, May, 
1924. 



THE NORTH TEMPERATE ZONE 109 

well illustrated in Glacier National Park in Montana, where the 
rolling prairie of the Blackfeet Indian reservation meets the main 
range of the Rockies, This prairie is rich in showy flowers, and 
very beautiful in the late summer. Near the base of the mountains 
are dense groves of aspens and scrub cotton-woods, while scattered 
conifers, — pines and spruces — begin to appear. 

The spring flora includes a number of pretty liliaceous species, 
fritillaries, adder-tongue (Erythronium), mariposa lilies (Cal- 
ochortus) and the blue quamash (Camassia esculenta), formerly 
an important food plant of the Indians. Other spring flowers, 
like those of the eastern prairies are also met with, but it is in late 
July and August that the prairie flora is at its best. 

The prairie is of the bunch-grass type, and the silky plumes of 
Stipa comata, are very conspicuous. The space between the grass 
tussocks is completely covered with an extraordinary profusion 
of showy flowers, reminding one of the flowery Swiss meadows. 

This prairie is in the foot-hill region at an elevation of about 
4,000 feet. Asters, golden-rods and several very beautiful species 
of Erigeron are perhaps the most abundant flowers, and another 
even showier composite is Gaillardia aristata, whose big yellow 
flowers with crimson discs are not infrequently seen in gardens. 

Lupins, Astragalus, and several vetches are abundant, and yar- 
row (Achillaea), and several umbellifers furnish most of the white 
flowers. Bluebells (Campanula rotundifolia) , one of the most wide- 
spread of northern plants, are extremely abundant and a showy 
mint (Monarda) was conspicuous, and here and there were masses 
of the beautiful pink blossoms of a dwarf rose (R. Arkansana). 

At the edge of the prairie, and along the banks of the streams, 
there is a luxuriant growth of tall herbaceous plants with showy 
flowers, the most abundant being the pink fire-weed (Epilobium) 
which occurs in immense quantities, and with it is often associated 
a very showy Senecio, with golden yellow flowers. The huge 
umbels of the cow-parsnip (Heracleum) are conspicuous in the low 
ground, and in places the ground is scarlet with the Indian paint- 
brush (Castilleja), of which there are a number of extremely 
beautiful species in the mountains near by. 

Southward the prairie-region diminishes in breadth, and the 
western plains gradually assume the character of dry steppes, or 
semi-deserts merging into the arid Mexican plateau. 



110 



OUTLINE OF PLANT GEOGRAPHY 



The southern prairies are drier than those of the north, the 
region having very hot summers, and there is a considerable 
development of annual species such as characterize the desert 
and semi-desert regions of the far western states. 



Florida 

The only part of the United States which can be called tropical 
is the southern part of Florida and the "keys" south of it. The 

climate is a hot humid one, 
Hkl and the vegetation is to a 
great extent West Indian in 
composition. 

The eastern part of the 
Florida peninsula is mostly a 
sandy plain with coral rock 
near the surface. The gritty 
soil is covered with a thin 
growth of coarse grass, and 
toward the south, the saw- 
palmetto {Serenoa serrulata), 
is very abundant as an under- 
growth for the pines which 
form an open forest. The 
principal species is the West 
Indian P. Caribaea. 

A common plant of these 
southern pine-barrens is a small 
eye ad (Zamia Floridana), 
which with a second species 
growing in moister situations 
are the only cycads found in 
the United States. 

Inland is the extensive re- 
gion of the "Everglades," 
formerly impenetrable swamps covered with a dense growth of 
saw-grass (Cladium effusum). Here and there are streams which 
lead into the interior of this great swamp. Sometimes there are 
areas of more elevated land covered with pine woods, and there 




Fig. 25. — Open pine forest (Pinus Cari- 
baea) ; undergrowth of saw palmetto, 
Miami, Florida. 




Ill 



112 



OUTLINE OF PLANT GEOGRAPHY 



are also cypress swamps. This region is now being drained on an 
extensive scale, the land being exceedingly productive. 

Along the coast of southern Florida are extensive mangrove 
formations, the principal species being the wide-spread Rhizophora 
mangle. 

Elsewhere extensive sandy beaches are encountered, with a 
characteristic strand flora. There is a mixture of typical northern 
species, like the sea-rocket (Cakile) and various grasses, and 
tropical forms like the saw-palmetto, and the beach morning 




Fig. 26. — Mangrove formation, Miami, Florida. 



glory (Ipomoea pes-caprae) , the latter a denizen of pretty much 
every tropical beach, the world over. Small Cacti, a Yucca and 
an Agave hint at Mexican relationships. 

While much of southern Florida is occupied by pine-barrens 
and the saw-grass swamps of the Everglades, there are numerous 
areas of greater or less extent distinguished b} r good soil, which 
support heavy growths of broad-leaved trees. These patches of 
forest are known locally as " hammocks, " and the vegetation is 
mainly composed of species common to the West Indies, or closely 
related ones, — in short, the flora of the hammocks is a distinctly 
tropical one. 



THE NORTH TEMPERATE ZONE 113 

With the live oaks, which usually are found in the hammocks, 
are associated species of figs (Ficus), mahogany, custard apples, 
laurels (Persea), Terminalia, Eugenia, Guayacum, Chrysophyllum, 
Sideroxylon, Mimusops and other trees and shrubs unknown 
elsewhere in the United States. The tropical character of the 
flora of south Florida is shown by the number of trees and shrubs 
of the madder family (Rubiaceae), a feature of most tropical coun- 
tries. In the temperate regions, most Rubiaceae are herbaceous. 

Various Araceae, Crinum and Hymenocallis of the Amaryl- 
lidaceae, Canna, and Thalia (Marantaceae), are all suggestive 
of the West Indies, and in the humid atmosphere of the hammocks, 
the trees are laden with epiphytic ferns, orchids and Bromeliads, 
presenting a pretty tropical picture. Florida has many species of 
orchids, some of which like Vanilla and Epidendrum are distinctly 
tropical types, and very handsome. Peperomia, a distinctly tropi- 
cal genus of the pepper family has two species in southern Florida. 

No feature of the flora of south Florida is more distinctly tropical 
than the palms, of which there are over a dozen species. Except 
for the palmettoes, which reach the Gulf states and Carolinas, all 
the palms of the eastern United States are confined to southern 
Florida. 

The coconut thrives along the shore as it does in most tropical 
countries, and in addition are some dozen other species of palms 
most of which are confined to this region. The finest palm of 
Florida is the royal palm (Oreodoxa regia), also a native of Cuba. 

Most of the conifers of Florida are pines, except in the swamps 
where the cypress occurs. An exception is the rare and interesting 
Torreya taxifolia, a member of the yew family, known only from 
a very limited habitat in middle Florida. The only other American 
species T. Calif ornica is confined to central California. 

The fern flora of Florida is not particularly rich, but in the south 
includes a number of tropical genera and species. Among these 
may be mentioned Vittaria, Ceratopteris, Acrostichum aureum, 
several species of Polypodium, and the remarkable Ophioglossum 
(Cheiroglossa) palmatum. The latter, as well as a good many 
others, grow as epiphytes in the hammocks. Several species of 
Selaginella, Psilotum triquetrum and Lycopodium cernuum, are 
also suggestive of the tropics. 



[uj(llBf ?ARy C 



CHAPTER V 
THE NORTH TEMPERATE ZONE— Concluded 

THE ROCKY MOUNTAINS AND PACIFIC SLOPE 

The main range of the Rocky mountains extends from New 
Mexico to northwestern Montana, and thence into the Canadian 
northwest. 

There are two pretty well marked regions which differ a good 
deal in character. The highest summits are in the southern 
part of the range, several peaks in Colorado, e. g., Pike's Peak, 
Long's Peak, exceeding 14,000 feet, but the mountains are far less 
abrupt than further north. In northern Montana and Canada, 
the main range is very much broken up, with very steep slopes 
and sharp peaks, but none of the latter attain the altitude of 
those further south. 

The national parks in Colorado, Wyoming and Montana, 
make the Rocky Mountains very accessible, so that the floras 
of these interesting regions can be easily studied. 

The country near Denver, and in Estes Park, illustrates very 
well the more salient features of the southern or Park region 
of the eastern Rockies. 

As one approaches the mountains in Colorado, the prairies 
of Kansas and Nebraska merge into a semi-arid region of bunch- 
grasses interspersed with xerophytic types* reminiscent of the 
true deserts of the south and west. This plain has an elevation 
of about 5,000 feet, and in places, the foot-hills form sloping 
table-lands or " mesas, ,: which are often traversed by streams 
descending from the mountains. 

The western edge of the mesa is both more sheltered and 
better watered than the eastern side, which slopes into the dry 
grass-land of the great plains. The vegetation of the western 
edge of the mesa is of a somewhat mixed type. There is sufficient 
moisture to permit the growth of a few conifers and aspens, 
and a number of shrubs and herbaceous species occur which 

114 



THE NORTH TEMPERATE ZONE 115 

require more moisture than those of the open plains. There 
is also an infusion of high mountain species, which mingle with 
those belonging to the dry prairie. 

A feature of the Colorado mountains are the "parks,' broad, 
grassy, nearly level valleys lying between high mountains. Estes 
Park is familiar to tourists, and is a good example of this forma- 
tion. 

These parks are fairly level valleys having an elevation of 
6,000 to 10,000 feet. The grassy meadows are rich in beautiful 
flowers, most of which are true sub-alpine types and quite dis- 
tinct from the plains flora. 

The Rocky mountain flora while having a good deal in common 
with the alpine floras of Europe, differs in many details. The 
gentians, campanulas and primroses, are much less in evidence, 
while on the other hand, American genera, e. g., Castilleia, Pent- 
stemon, Mimulus, as well as Aster and Solidago and some other 
Compositae, are very abundant, both as to species and indi- 
viduals, and these are mostly absent from the European moun- 
tains, or in the case of the Compositae, much less developed. 
One of the finest of the mountain flowers is the great blue and 
white columbine (Aquilegia coerulea) the state flower of Colorado. 

Above the parks the mountain sides are in many places clothed 
with a fairly heavy forest mostly of conifers. On Pike's Peak 
the timber line ascends to 11,500 feet. The forest is composed 
of several species. The yellow pine (Pinus ponderosa, var. sco- 
pulorum) is abundant above 6,000 feet, usually associated with 
Douglas fir (Pseudotsuga), these being the most widely distributed 
of the western conifers with the possible exception of the lodge- 
pole pine (P. Murrayana). Over large areas the Engelmann 
spruce (Picea Engelmanni) is the predominant tree, and is wide- 
spread in the Rockies, but scarcely reaches the Pacific coast. 
This species ascends to the timber line, occasionally over 12,000 
feet. In the higher altitudes, the yellow pine gives place to the 
limber-pine (P. flexilis), which reaches its best development further 
north. The alpine fir (Abies lasiocarpa) also reaches timber line, 
and lower down the Pacific white fir (Abies concolor) is met with, 
but never reaches the dimensions attained in the Pacific forest. 
On the dry slopes low bushes of juniper are common, as else- 
where in the western mountains. 



116 OUTLINE OF PLANT GEOGRAPHY 

Nowhere do the deciduous trees play an important role. Except 
for thickets of aspens the deciduous trees are confined to the 
canyons and river banks of the lower elevations. Birches, wil- 
lows and cotton-woods may be found in such localities, and 
several species of oaks occur in Colorado, but are never trees 
of large size, and usually merely shrubs, forming part of the 
"chaparral" or scrub on the dry hillside- 

North of the high mountains of Colorado is an elevated plateau 
which is traversed by the Union Pacific railway in Wyoming. At 
the continental divide, about 8,000 feet elevation, the country is 
an undulating dry prairie or steppe with almost no trees, and 
in general scanty vegetation. 

The Yellowstone Park is approached over much the same 
type of country, and is also a relatively level area with no high 
mountains in the immediate vicinity. The hills are covered 
with a forest of lodge-pole pine, but the trees are small. In 
the early summer there are a good many attractive flowers 
growing in the woods and on the grassy slopes. One of the most 
abundant is a large yellow adder-tongue (Erythrom'um grandi- 
florum). Other characteristic flowers are some fine larkspurs 
and fringed gentians, and a small orange fritillary {Fritillaria 
pudica). 

The barren soil of the peculiar thermal formations is mostly 
bare, but it is interesting to note that some species, usually found 
on the seashore, or salt marshes (Salicoimia herbacca, Rumex mari- 
time!), have established themselves on the hot alkaline geyser for- 
mations. 

The main range of the Rockies, in northwest Montana and 
Canada, is extremely rugged, broken up into separate mountain 
masses with steep slopes and sharp peaks. Owing to the latitude 
there is much more snow than in the southern Rockies, and glaciers 
are common, especially in the Canadian mountains, and the snow 
line is much lower. 

The main range traverses Glacier Park in northwest Montana, 
and affords a most interesting study in plant distribution. 

The prairie flora to the east has already been referred to, and an 
analysis of its constituents shows a mixture of eastern and western 
species, the former rather predominating. 

The eastern slopes of the mountains are exposed to the extremely 



THE NORTH TEMPERATE ZONE 



117 



severe weather conditions of eastern Montana, intense cold, great 
summer heat, and scanty rainfall; hence the vegetation of the 
exposed areas is decidedly xerophytic. 

There are several lakes, more or less protected by the surrounding 
mountains, and about these, and in sheltered canyons, there is a 




Fig. 27. — Coniferous forest, Glacier National Park, Montana. 

hemlock; right, western white pine. 



Left, western 



fairly luxuriant forest in which Douglas fir and Engelmann spruce 
predominate. Both of these trees descend to a much lower eleva- 
tion than in Colorado, and the same is true of the limber-pine 
which becomes a fair sized tree, while usually it is a high mountain 
species of low and spreading habit. Some of the drier areas are 
occupied by nearly pure stands of lodge-pole pine, and low junipers 
grow on the exposed hillsides, where there is often a dense scrub 
or chaparral composed of a variety of shrubs. These include two 



118 



OUTLINE OF PLANT GEOGRAPHY 



species of buffalo-berry (Shepherdia) , raspberries, currants, sumac, 
huckleberries, plums, and others. 

Crossing the divide to the west side of the range, one finds within 
less than twenty miles a remarkable difference in the forest 
vegetation, due to a marked change in climate. The west side 





Fig. 28. — Forest, Glacier National Park. At right, center, cotton-wood (Populus 

trichocarpa) . 

of the range evidently intercepts a large share of the moisture 
brought by the west winds from the Pacific, and the rainfall is 
consequently very much greater than on the eastern side of the 
mountains. Moreover the winter cold is much tempered by the 
westerly winds. 

The forest about Lake McDonald at the western base of the 



THE NORTH TEMPERATE ZONE 



119 



range in Glacier Park is a very heavy one, and composed of a 
remarkable variety of conifers, which attain a much greater size 
than those of the eastern slope. 

The most abundant tree is the western larch (Larix occidentalis) , 
a graceful tree, sometimes exceeding 150 feet in height. This tree is 
deciduous, like its relative the 
eastern tamarack. With this 
are the Douglas fir and Engel- 
mann spruce, and at higher 
elevations the alpine fir. Be- 
sides these, however, are spe- 
cies belonging to the humid 
Pacific coast forest, the grand 
fir (Abies grandis), giant arbor- 
vitae (Thuja plicata), and 
western hemlock. The west- 
ern yew (Taxus brevi folia) is 
common, but does not be- 
come a tree. For the number 
of species of conifers growing 
together, this forest has few 
if any equals. 

The peaty soil supports an 
interesting assemblage of bo- 
real shade-loving plants. The 
twin-flower (Linnaea) forms 
extensive carpets in places, 
and the Indian-pipe (Mono- 
tropa uniflora) lifts its clus- 
ters of dead-white stems and 
flowers from the dank mould. 
Pipsissewa (Chimaphila), and several species of Pyrola; the 
dwarf Cornel, and several orchids, e. g., coral-root (Corallorrhiza), 
rattlesnake plantain (Goodyera); Clintonia uniflora, Bcrbcris 
repens, Aralia nudicaulis. 

Where the shade is less dense, as along the banks of the small 
streams, and in clearings, a number of characteristic species are 
noted. Elder, cow-parsnip (Heracleum), and maples make fine 
masses of foliage in the low ground, and with these are associated 




Fig. 29. — Forest interior, giant arbor- 
vitae; Lake McDonald, Glacier Na- 
tional Park. 



120 OUTLINE OF PLANT GEOGRAPHY 

the handsome leaves and large white flowers of the thimble-berry 
(Rubus Nutkanus), and the "devil's club" {Echinopanax horridus), 
a handsome but horribly spiny shrub, an emigrant from the 
Pacific coast. Ferns are not uncommon, and the lady fern 
(Asplcnium fdix-focmina) is especially abundant and luxuriant 
in the low ground; also a variety of shrubs, snowberry (Symphori- 
carpus), Spiraea, Viburnum, twdn-berry (Lonicera involucrata) . 

While deciduous trees are greatly in a minority, the forest is 
not so exclusively coniferous as that of the drier parts of the 
mountains. The canoe-birch is not uncommon, and becomes a 
tree of considerable size, while the balsam poplar (Popidus tricho- 
carpa) is a lofty tree with tall straight trunk, rivalling the conifers 
in height. A small maple (Acer, glabrum) is also common. 

Showy flowers are less abundant than in the drier and more 
open country of the eastern side of the mountains; but at 
higher elevations there are many beautiful alpine and sub-alpine 
species. 

The alpine meadows of the northern Rocky Mountains have 
a profusion of extremely beautiful flowers, and there are many 
interesting and attractive rock-species also, like the Pentstemons, 
Epilobium latijolium, various saxifrages, stone-crops, etc. 

The meadows early in the season are adorned with the large 
yellow adder-tongue, which soon ripens its fruit and is followed 
by a great variety of attractive flowers. Yellow arnica, white 
valerian, blue gentians; and lupins and magnificent scarlet, 
crimson and pink Castilleia abound, as well as many other pretty 
and interesting species. In the wetter ground a beautiful pink 
Mimulus (M. Lewisii), is abundant, as well as yellow Senecio, 
larkspurs, forget-me-nots, asters, Erigeron, and a pale yellow 
columbine, quite different from the blue Colorado species. The 
curious little " elephant's head" (Pcdicularis Groenlandica) is not 
uncommon, and the pretty grass of Parnassus (Parnassia) is 
abundant in moist places. A very conspicuous plant of the sub- 
alpine region is the green false-hellebore (Veratrum viride), whose 
big plaited leaves, and tall racemes of greenish flowers, are ex- 
tremely common. 

Among the rock-plants is the mountain avens (Dryas octopetala), 
a species common to the arctic and alpine regions of both hem- 
ispheres. Other wide spread species are Silene acaulis, Iceland 



THE NORTH TEMPERATE ZONE 



121 



poppy, and the little primrose, Primula farinosa. With these are 
associated such distinctly American genera as Pentstemon and 
Phlox. 

Northwestward, the western Rocky Mountains unite with the 
northern Cordillera in Idaho, Washington and British Columbia; 
and this accounts for the strong infusion of Pacific coast species in 
the Rockies of Idaho and northern Montana. These are mostly 




Fig. 30. — Alpine vegetation, Glacier National Park; left, Alpine fir; right, false- 
hellebore {Veratrum viride). 

absent from the southern Rocky Mountains, where the drier and 
hotter climate is less suited to these northern moisture-loving 
species. 

West of the main continental divide is the extensive plateau 
region, the Great Basin, comprising most of Utah and Nevada, 
and parts of Idaho, Oregon and Washington. This is a region of 
arid steppes and broken mountain ranges, with light precipitation, 
this being specially marked in the southern areas. 



122 



OUTLINE OF PLANT GEOGRAPHY 




The arid climate of the Great Basin is due largely to its almost 
complete encirclement by lofty mountains. The western Cordil- 
lera forms an effective barrier against the moist Pacific winds, 
and the southern portion is open to the hot winds from the Mexican 
plateau. Except for the Columbia and its tributaries, which 
traverse the northern parts of the basin, there are no streams of 
importance within the area, and these are often lost in the desert 

sands, or as in the case of the 
Jordan, flow into saline lakes. 
Parts of the region, like that 
adjacent to the Great Salt 
Lake, are deserts of the most 
pronounced type, quite desti- 
tute of vegetation; or the arid, 
often alkaline soils support 
only a thin growth of such 
plants as sage-brush (Arte- 
misia), and grease- wood (Sar- 
cobatus) and similar shrubs 
capable of enduring long 
periods of drought. 

This region is traversed by 
the Union Pacific railway, and 
between Cheyenne and Reno 
one has an opportunity of see- 
ing the most characteristic por- 
tions of this Great American 
desert. 

From an elevation of over 
8,000 feet at the continental 
divide there is a descent of about 4,000 feet into Utah and Nevada. 
The bunch-grass prairie of Wyoming passes gradually into a dry 
steppe with thinly scattered bunch-grasses interspersed with sage- 
brush and other xerophytic growths. The rocky hillsides support 
a few scrubby junipers and firs, and various low shrubs and herba- 
ceous plants in the sheltered hollows among the rocks; but these 
mostly disappear in the lower parts of the basin. Where there 
are streams, the banks are lined with willows and cotton-woods, as 
well as a number of deciduous shrubs, currants, elder, roses, 




Fig. 31. — Sub-alpine meadow, Glacier 
National Park. 



THE NORTH TEMPERATE ZONE 123 

spiraea, etc., and herbaceous plants, like asters, golden-rod, willow- 
herb, and others. 

Along the railway in Utah and Nevada as far as one can see, is 
a monotonous landscape of barren plains and low hills sometimes 
almost destitute of vegetation, but usually covered with a dull- 
green mantle of sage-brush which is the predominant plant of this 
region. Between the clumps of sage-brush, there are often scat- 
tered tufts of grass, and sometimes after spring rains, various 
flowers appear for a brief season. Among these may be mentioned 
the "sego lily" of Utah, a pretty lily of the genus Calochortus; 
evening primrose, lupins, and various other showy annuals. 

When the soil is strongly alkaline, grease-wood (Sarcobatus 
vermicularis) takes the place of the common sage-brush, and with 
it occur other plants characteristic of alkaline soils, e. g., Atriplex, 
Bigelovia, Suaeda and others. 

This dreary landscape continues almost to the foot of the 
Sierras, where the effect of the coastal moisture begins to make 
itself manifest. 

This arid region extends northward into Oregon and Washington, 
where desert conditions are less extreme, and the northern portion 
of the Great Basin is traversed by the Columbia which breaks 
through the Cascade mountains and reaches the sea. A con- 
siderable portion of the Columbia basin lies in this arid region, and 
although much of it is very dry, there is a true forest growth in 
many places, and even at the lower elevations the yellow pine may 
form open forests. Only a small area in eastern Washington is 
comparable to the deserts of Nevada and Utah. 

The desert of the Great Basin has a much more monotonous 
vegetation than the regions to the south. The Cacti, Yuccas, 
and other striking forms of the deserts of Arizona and southern 
California, are almost entirely absent. These are of Mexican 
origin, and apparently not fitted for the severe winters of the 
northern desert. 

Of course, even in a true desert region, the sheltered valleys, 
watered by mountain streams, may develop a relatively luxuri- 
ant vegetation, and if sufficiently open are available for cultiva- 
tion. Before reaching Ogden, the railway passes through the can- 
yon of the Webber River, which furnishes water for irrigation, and 
where the floor of the valley expands there are prosperous looking 



124 



OUTLINE OF PLANT GEOGRAPHY 



ranches with luxuriant fields of alfalfa and other crops, and fine 
orchards. The contrast between the forest growth of some of 
these sheltered canyons, and the barren desert without, is quite 
extraordinary. 

As the lower slopes of the Sierra and the Cascades are reached, 
the effect of the increasing moisture is seen in the greater number 
of trees as one ascends toward the summit of the ranges. Although 
the eastern slopes of the Sierra are much drier than those of the 
Pacific side, nevertheless there is an abundant growth of fine 
trees in which the yellow pine predominates. 

This intermediate region is well shown near Lake Tahoe, 




-Desert vegetation, Utah. Sage-brush {Artemisia sp.), Chrysothamnus 
sp. Photo., Mr. Fred Buss. 



which lies at about 6,000 feet elevation on the boundary between 
Nevada and California. About the eastern shore, the yellow pine 
is the commonest tree, and sage-brush and other xerophytic plants 
occupy the ground between the trees. On the western side, es- 
pecially at the northern end of the lake, the effect of an extremely 
heavy snow-fall is seen in a forest of mixed conifers, in which 
the white fir (Abies concolor), is the commonest species, with 
sugar pine (P. Lambertiana) , yellow pine, and incense cedar (Li- 



THE NORTH TEMPERATE ZONE 



125 



bocedrus decurrens). In moister ground the tamarack (Pinus 
Murrayana) occurs. 

The drier ground is covered with chaparral, in which the char- 
acteristic western shrubs Manzanita and Ceanothus are conspicu- 
ous. Alpine meadows like those of the Northern Rockies are 
common, and in general the vegetation is much like that of the 
western Rockies at similar altitudes. 

The Pacific Coast 

Climatic conditions on the Pacific Coast are very different 
from those elsewhere in North America, where for the most part 




~wftm& ^ 




Fig. 33. — Coniferous forest, Lake Tahoe, California. Left, incense cedar, yellow 

pine; right, white fir. 

the climate is a pronounced continental one, with great extremes 
of heat and cold. 

The whole coast, from Sitka to San Diego enjoys a remarkably 
equable climate, insular in type, rather than continental. The 
two great factors concerned are the lofty range of the Great Cor- 
dillera, protecting the coastal strip from the great temperature 
fluctuations of the interior, and secondly the proximity of the 
ocean whose surface waters maintain a nearly constant tempera- 
ture, which has a very great influence on that of the coast, especially 
as the prevailing winds are from the sea. 



126 OUTLINE OF PLANT GEOGRAPHY 

The effect of the ocean temperature is especially marked on the 
immediate coast. San Francisco, lat. 38°, about the same as 
Washington, has a mean annual temperature of 55°F, with only 
ten degrees difference between the warmest and coldest months, 
viz., 60°-50°. In Washington, the difference is more than four 
times as great. The moderating effect of the ocean is particularly 
noticeable at the north. Sitka, seventeen degrees north of New 
York, has almost exactly the same temperature (+1°C) for its 
coldest month. 

Away from the immediate coast the temperature is greatly 
influenced by topography. Where the cool ocean winds in summer 
are intercepted by mountain ranges, as in central and southern 
California, arid regions like parts of the San Joaquin Valley and the 
Mojave desert show the highest summer temperatures of any part 
of the United States. For example at Needles, on the California 
bank of the Colorado River in the Mojave desert, there are few 
days in summer when the thermometer does not reach 100°F, 
and 120° and even more are sometimes registered. This same 
region, in winter, is subject to sharp frost. 

The distribution of rain on the Pacific Coast is also very different 
from that of eastern North America. The rainiest regions are at 
the north, where some of the stations have annual means of over 
100 inches, and exceed any points in the eastern L T nited States. 
Southward the rainfall diminishes rapidly until at the Mexican 
boundary it is ten inches or less. 

Like the temperature, the rainfall is also strongly controlled 
by topography, especially by the trend of the mountains, and there 
may be a great difference in precipitation within a short distance, 
due to topography. At Stanford University which lies to the 
east of the outer coast range, the annual rainfall averages less 
than 20 inches, but at some stations, e. g., Boulder Creek, about 
twenty-five miles away in an air-line, it is more than three times 
as much. 

Of course these great differences in temperature and moisture 
exercise a great influence upon the vegetation. For example, the 
Santa Clara Valley in the vicinity of Stanford University, is an 
open grassy savanna, with scattered oak trees, and only on the 
northern slopes of the hills do the trees form an approach to a 
forest. In the mountains, however, in the regions of heaviest 



THE NORTH TEMPERATE ZONE 



127 



rainfall, is a magnificent forest of giant redwoods, with an under- 
growth of almost tropical luxuriance. 

Throughout the southern part of the Pacific Coast, including 
all of coastal California, the winter is a period of active vegetation. 
The rains are confined to the cooler part of the year, the summer 
being quite rainless in most of California; and as far north as 
British Columbia the rains are small in amount compared with the 
autumn and winter precipitation. Thus in lowland California, 




Fig. 34. — Santa Clara Valley, near Stanford University. White oak, with 

mistletoe (Phoradendron flavescens). 

at least, the growth periods are reversed when compared with 
eastern North America. 

During the long dry summer the native vegetation is largely 
dormant, but with the autumn rains, in October and November, 
a host of annual grasses and herbaceous flowers sprout, and the 
perennial herbs, especially the numerous bulbous and tuberous 
species, start into growth, continuing to grow through the rainy 
winter, flowering in spring, ripening their fruits and dying down 
after the spring rains have ceased. 

As in all climates with mild winters, there is a preponderance 
of evergreen trees and shrubs. Not only are coniferous trees 



128 OUTLINE OF PLANT GEOGRAPHY 

developed to a remarkable degree, but a great variety of broad- 
leaved evergreens are found, especially in the southern part of 
the area. Evergreen oaks, laurels, huckleberries, barberries, and 
other less familiar genera, abound in the Californian flora. 

The mild climate and a very heavy rainfall result in a luxuriant 
forest as far north as about 60° in coastal Alaska, corresponding 
in latitude to northern Labrador and the southern tip of Green- 
land, regions of arctic cold and destitute of any forest vegetation. 

A feature of the Pacific coast is an extraordinary development 
of the giant kelps, these huge brown sea-weeds growing in profu- 
sion on the rocky shores from Alaska to the Mexican boundary, 
being especially abundant in Central California. 

The best known of the giant kelps is the great bladder-kelp 
(Macrocystis pyrifera), which also is found in the colder waters of 
the southern hemisphere. Other kelps reaching a great size are 
species of Alaria, Egregia, Nereocystis and Pelagophycus. The 
two latter may reach a length of 100 feet or more, and grow in 
deep water, the huge leaves being buoyed up by a single globular 
float, which in Pelagophycus is as large as a coconut. 

The majority of these kelps are peculiar to the Pacific Coast 
of North America, and constitute one of the most remarkable 
features of the Pacific Coast vegetation. 1 

The typical coastal flora of southern Alaska is well developed 
about Sitka. The forest is very dense, made up mostly of two 
species, the Sitka spruce (Picea Sitchensis) and a hemlock 
(Tsuga Mertensiana). A third species, the Alaska cedar (Cham- 
aecyparis Xootkatensis), has been largely exterminated, as its 
wood is especially prized for making the great dugout canoes, 
and for wood carvings. 

While the trees of this forest do not attain the great size found 
further south, still they are fine large trees, the spruces often 
attaining a height of over 100 feet, with a diameter, occasionally, 
of 6 to 8 feet, The forest floor is covered with a dense carpet 
of mosses, which also cover every stump and fallen log. Among 
the mosses grow the usual low evergreen species of the northern 
forests, e. g., Pyrola, Linnaea, dwarf cornel, various species of 
Lycopodium, and ferns, etc. The abundant and constant mois- 

1 The algae of the Alaska coast are decribed at some length by Harshberger, 
loc. cit., p. 5^7. 



THE NORTH TEMPERATE ZONE 129 

tare is especially favorable for seed-germination, and myriads 
of tiny spruces and hemlocks are found on every log and stump, 
growing in the moss. As the logs decay very slowly, it is common 
to see a young tree perched on a stump several feet above the 
ground, sending down its roots until they reach the earth. When 
the log or stump finally decays and disappears, the tree is sup- 
ported by a cone of stilt-like roots often five or six feet high. 

In every clearing is an impenetrable jungle of shrubs and 
young trees, among which the spiny devil's club (Echinopanax) 
is only too abundant. It is, however, a remarkably handsome 
plant, with its large palmate leaves and spikes of showy red 
berries. This, with the huge leaves of the Aroid, L} r sichiton, 
known locally as " skunk-cabbage, " gives quite a tropical aspect 
to the edge of the jungle. The salmon-berry {Rubus spectabilis) 
with pretty pink flowers, and showy red and j^ellow fruit, is a 
common and characteristic shrub. Red-berried elder, huckle- 
berries, mountain ash, roses and spiraea, are also abundant 
in the woodland thickets, and in low ground are extensive growths 
of the giant horse-tail (Equisetum telmateia). 

Deciduous trees, willows, poplars, alders and small maples, 
are mostly restricted to the banks of the numerous streams. 

Sphagnum bogs abound near Sitka and contain the usual 
northern bog-species: sundews, cranberries, Kalmia glauca, 
various bog orchids, buck-bean (Menyanthes), etc., with numer- 
ous grasses and sedges, including species of cotton-grass (Eri- 
ophorum). The pools in the Sphagnum bogs are very rich in 
small algae, e. g., desmids, diatoms, and a great variety of other 
unicellular species. 

British Columbia and Puget Sound 

The general character of the coastal vegetation of British 
Columbia and Puget Sound, is much the same as that of south- 
east Alaska, but with the warmer climate, the number of species 
increases and the trees reach enormous size. About Puget Sound, 
the Douglas fir (Pseudotsuga Douglasii), 1 is the most abundant 
species, and is the most important timber-tree of the Pacific 
Coast. Originally forests of this species everywhere lined the 

1 P. taxifolia. 



130 OUTLINE OF PLANT GEOGRAPHY 

coast, but the accessible areas have been mostly stripped of 
timber, with the development of the cities and agricultural 
districts. These forests, where they still exist, are very dense, 
and the trees attain a great height, occasionally upwards of 
300 feet. 

The trees of the Alaska coast forest also occur, and the Sitka 
or "tideland" spruce attains its greatest development here, 
as does the giant arbor-vitae (Thuja plicata) known usually as 
" cedar." Of the deciduous trees of this region, the big-leaved 
maple (Acer macrophyllum) and the handsome flowering dog- 
wood (Cornus Nuttallii) are conspicuous. These with the smaller 
vine-leaved maple (A. circinnatum) , color brilliantly in the 
autumn and make fine masses of color in the evergreen forest. 
From Washington south, the fine western rhododendron (R. 
Calif ornicum) is abundant, as well as the shrubs found in the 
more northern forest. Another characteristic shrub is the salal 
(Gaultheria shallon), related to the little wintergreen of the Atlan- 
tic states. 

In the neighborhood of Tacoma are some open prairies where 
are oaks (Quercus Carry ana) in scattered groves; but as a rule, 
oaks are not abundant in this region. 

While the forest has been largely cut away from the lowlands, 
one can get an idea of the primaeval forest from the pieces of 
forest land that have been reserved for parks. Thus Stanley 
Park at Vancouver has enormous, specimens of tideland spruce, 
cedar, and Douglas fir, and shows what the coastal forests were 
before the advent of the white man. 

The western slopes of the Cascades are covered with dense 
forest in which the Douglas fir is much the most abundant tree, 
and often forms pure stands of great extent. 

The great volcanic peaks which rise from the Cascades illus- 
trate very beautifully the change in vegetation as one ascends 
from sea -level to the regions of perpetual snow and ice. The 
snow-line is about 6500 feet elevation. 

The finest of all these mountains, Mt. Rainier, is easily acces- 
sible, and shows perfectly the different zones of vegetation. 
Moreover, as it is a National Park, the forest is largely intact. 
At the base the forest is mostly Douglas fir. Above this the 
Douglas fir is associated with white pine (P. monticola), hemlock, 



THE NORTH TEMPERATE ZONE 



131 



and two fine firs, Abies grandis, and A. amabilis. Above 3,500 
feet, the Douglas fir is replaced by the noble fir (A. nobilis), 
and at timber line, the Alpine fir (A. lasiocarpa), and white- 
barked pine (P. albicaulis) are found. 

The ground flora of the forest is very much the same as that 
in the northern Rockies, and the same is true of many of the 
species making up the luxuriant thickets of shrubs in the more 
open places. The vine-leaved maple, already referred to, is 




Fig. 35. — Avalanche lilies {Erythronium montanum), Mt. Ranier. 

one of the commonest and most beautiful. It closely resembles 
some of the Japanese maples, and like them in the fall assumes 
gorgeous hues of crimson and scarlet. 

The alpine flora of Mt. Rainier is perhaps unrivalled in Amer- 
ica. As the snow melts, the alpine meadows are adorned with 
a great profusion of beautiful flowers. Beds of big snow-white 
" avalanche lilies" (Erythronium montanum) spring up close 
to the snow-banks, and dense masses of brilliant crimson Cas- 
tilleia, blue lupins, and pink heather (Bryanthus), make superb 
expanses of vivid color, and with these are many others, many 
of them wide -spread alpine species. The unusual profusion 
of flowers on Mt. Ranier is probably due to the abundant mois- 



132 OUTLINE OF PLANT GEOGRAPHY 

ture from the great snow fields and glaciers which cover the 
mountain for a distance of nearly 8,000 feet. 

The eastern slopes of the Cascades are much drier, and the 
plateau traversed by the Columbia and its tributaries is arid, 
and belongs rather to the Great Basin than to the Pacific Coast. 

The southern Cascades have a much less luxuriant vegeta- 
tion than in the Puget Sound region, and this becomes very 
marked as the California boundary is reached. The northern 
conifers become less numerous, and the yellow and sugar pines, 
and white fir are more in evidence, and indicate an approach 
to the drier climate of the Sierra Nevada. 

Along the coast, however, the dense wet forest belt is con- 
tinued into northern California, but the characteristic trees 
of the northern forests are to a great extent replaced by the 
redwood {Sequoia sempervirens) , which in some places forms 
pure stands of great extent, and throughout the great redwood 
belt, reaching from southern Oregon to central California, is 
the predominant species. 

Associated with the redwood, throughout most of its range, 
is the tan-bark oak (Pasania densiflora) the only American repre- 
sentative of a genus otherwise restricted to Himalayan and Indo- 
Malayan regions. Another beautiful tree of the redwood region, 
but not confined to it, is the madrono (Arbutus Menziesii), with 
broad evergreen leaves suggesting a magnolia. This reaches 
its greatest dimensions in central California. 

Owing to the great diversity of topography and climate, Cali- 
fornia surpasses any other equal area in the United States in the 
richness of its flora. Not only is the number of species very great 
but a suprisingly large number are peculiar to the state, and often 
of very limited range. 

Covering 10 degrees of latitude (42° to 32°) and with a coast- 
line nearty a thousand miles long there is naturally considerable 
range of climate due to latitude; but this is very much less marked, 
as regards temperature, than is the case on the Atlantic coast, 
due to the uniform temperature of the Pacific. 

While the temperature in California is relatively little affected 
by latitude, this is not true of the precipitation. Eureka, near the 
northern end of the state has more than four times as much rain 
as San Diego; while some stations in northwest California may have 




Plate XI. — 



Redwood forest, Humboldt County, California. Photo., courtesy of 
Save the Redwoods League. 

133 



134 OUTLINE OF PLANT GEOGRAPHY 

more than a hundred inches annually. On the other hand, 
some places in the desert of southern California are almost 
rainless. 

Topography plays an extremely important role in determining 
the climate of different parts of California. The principal moun- 
tains are parallel with the coast. In central California there are 
three, the outer and inner Coast Ranges, and the Sierra Nevada 
forming the eastern boundary of the state. At the north the 
Siskiyous separate California from Oregon, and connect with the 
southern Cascades. In central California the Tehachapi Moun- 
tains connect the Coast Ranges and the southern Sierra, and in 
southern California are more or less isolated lofty mountains, the 
San Bernardino and San Jacinto ranges. 

These mountain ranges exercise an immense effect on the climate 
of the adjacent regions. Thus while the western slopes of the 
outer Coast Range receive a heavy rainfall, so that the northern 
redwood forest is probably the heaviest stand of timber in the 
world, the valleys to the east are too dry to support anything but 
a scattered growth of oaks, and are often quite treeless. 

In the southern part of the state, where the precipitation at 
best is scanty, the moisture-laden winds from the ocean are quite 
unable to reach the interior valleys and plateaus, and these are 
more or less complete deserts, like the Mojave desert, Death 
Valley, and the Colorado desert. 

In central California, the great central valley, made up of the 
Sacramento and San Joaquin, has a very light rainfall except in 
the upper Sacramento Valley. For the most part the rainfall is 
insufficient for ordinary farming, but under irrigation these val- 
leys are extremely productive, and a great quantity of grain, 
including rice, and fruit of all kinds, make this great valley the 
most important agricultural region of California. 

There may be great differences in temperature and precipita- 
tion due to local conditions. For example, San Francisco, situated 
on a peninsula exposed to the full effects of the ocean wind and fog, 
has a remarkably cold summer climate, the mid-summer maximum 
usually being below 70°F. In the central valley, at this season, 
intense heat prevails, while in the deserts of southern California 
are the hottest regions in the United States. Even in the imme- 
diate vicinity of San Francisco places lying inside the Coast Range, 



THE NORTH TEMPERATE ZONE 135 

e. g., Stanford University, usually have summer maxima ten to 
twenty degrees higher than the city. 

While the west side of the Coast Ranges intercepts much of 
the moisture from the ocean winds, so that the valleys are compar- 
tively dry, the mountains are not of sufficient elevation to shut off 
the Sierra from the moisture laden winds, and the west side of 
the Sierra above about 4,000 feet has a very heavy precipitation, 
mostly in the form of snow, which allows the development of a 
forest of giant trees. 

The main range has an average elevation of about 10,000 feet, 
the highest peak, Mt. Whitney (14,502 ft.) being the highest 
point in the United States, outside Alaska. This great barrier 
effectually protects California from the extreme climate of the 
Great Basin. Owing to the southerly position, the snow fields 
are much less developed than in the Cascades, and except, on Mt. 
Shasta in northern California, glaciers are practically absent. 
There is, however, a very heavy snow-fall, the melting snow pro- 
viding the necessary moisture for the great forests that clothe much 
of the western slopes of the Sierra, and feeding the numerous 
glacial lakes of the high mountains, and the streams that flow 
from them. 

It is interesting to note that Mt. Whitney, the highest point 
in the United States, overlooks Death Valley, also in California, 
the lowest spot, over 300 feet below sea-level. 

The coast of California is very varied in character, and this 
is reflected in the great variety of the coastal vegetation. Through 
much of the state, the outer Coast Range runs close to the sea, 
and as at the Golden Gate, high cliffs rise sheer from the water, 
and bold rocky headlands are a feature of much of the coast, 
especially in central California. Low clay bluffs are sometimes 
met with and elsewhere broad sandy beaches and dunes. At San 
Francisco and near Monterey, dunes are developed on a great 
scale. Salt marshes occur in such sheltered places as parts of San 
Francisco Bay, but are comparatively rare. 

The rocky shores with extensive reefs and tide-pools, harbor 
an extraordinary variety of algae and the whole Pacific Coast 
from Alaska to Mexico is extremely rich in both red and brown 
species. In the deeper and quieter water are delicate red algae 
in great variety; but the species growing on the rocky ledges and 



136 



OUTLINE OF PLANT GEOGRAPHY 



reefs, exposed to the tremendous Pacific surf, are usually tough 
and leathery in texture, fitted to withstand the buffeting of the 
heavy waves. Some of these large red species, like the spiny 
Cigartina and Iridea, the latter reflecting peacock-hues in the 
shallow pools, are very conspicuous. 

The most striking marine plants of this coast, however, are the 
big brown sea-weeds, or kelps, which reach extraordinary size, 

and show great diversity of 



form. Some of them, like 
Fucus, are entirely exposed at 
low tide, and drape the rocks 
as they do on the northern At- 
lantic coast; others are rooted 
in water far below tide mark, 
and their leaf-like fronds float 
near the surface, often buoyed 
up by air-bladders. The tough 
stems are anchored by strong 
root-like hold-fasts in water 
many fathoms deep. 

Of these giant kelps, the 
great bladder-kelp (Microcys- 
tis) is abundant from Alaska 
to Santa Barbara, and great 
beds of this kelp, off shore, act 
as a quite efficient breakwater. 
Another very large species, 
Nereocystis Lutkeana, some- 
times attains a length of over 
100 feet. The big leaves are 
attached to a single air-bladder 
the size of a baseball, the stem tapering gradually to the slender 
solid stem. This huge plant is the growth of a single season. 
Much like Nereocystis is the " bull-kelp" (Pelagophycus) of 
southern California, in which the float is the size of a coconut, 
and the big leaves are attached to two great antler-like branches. 
Another kelp peculiar to the Pacific coast is the sea-palm (Pos- 
telsia palmaeformis) , a stout upright plant about two feet high 
growing on rocks exposed to the full force of the breakers. It 





I 



Fig. 36. — Sea-palms (Postelsia palmaefor 
mis). Photo., Miss E. M. Bartlett. 



THE NORTH TEMPERATE ZONE 



137 



resembles a small palm tree, and the flexible trunk is perfectly 
adapted to withstand the pounding of the surf, being so firmly 
anchored to the rocks that it can be removed only by chopping 
it loose. 

The flora of the sand-dunes is a very varied and attractive one, 
and may be seen in perfection on the shores of the Monterey 
peninsula. Especially conspicuous are the masses of bush- 




-Sand-dunes, Monterey Peninsula, California. 
Monterey pine. 



The trees are 



lupins, with yellow, white and purple flowers, making a fine show 
of color when in bloom. Other characteristic shrubs are species of 
Ceanothus, "wild lilac," and "Cascara" (Rhamnus), as well as 
willows, and several Compositae. Sometimes the Monterey pine 
(Pinus radiata) and live oak (Quercus agrijolia) are found on the 
inshore dunes, where they form dense low thickets. 

Besides grasses and sedges, there are a number of showy herba- 
ceous plants, among which the yellow and pink umbels of the 
" sand-verbenas" (Abronia) are conspicuous. 

Where there are bluffs back of the dunes, upon them are found 
a number of striking flowers, which may also invade the dunes. 
A large Mesembryanthemum {M. aequilaterale) is very common, 



138 OUTLINE OF PLANT GEOGRAPHY 

and ( Jastilleia with flowers varying from cream to scarlet are among 
the common and very showy species. A large aster-like Erigeron 
is also very abundant. 

The steep cliffs above the Golden Gate show a similar flora, 
and there are also many others: buttercups, Iris, Eschscholtzia, 
Sanicula, evergreen strawberries (Fragaria Chilensis), cow- 
parsnip (Heracleum), Fritillaria, etc. Several ferns and horse- 
tails are also common in places. 

A feature of the coastal flora of California is the occurrence of 
several endemic conifers of very limited range. The Monterey 
pine, and cypress (Cupressus macrocarpa) are practically confined 
to a few miles of coast on the Monterey peninsula, and in southern 
California, the Torrey and Parry pines are even less abundant. 

In places there is a "mesa" extending from the base of the outer 
Coast Range to the sea, with bluffs of moderate height along the 
shore. These mesas in central California owing to the cool summer, 
and frequent fogs, may be covered with a permanent turf, and in 
the spring are decked with a great variety of pretty flowers. 

About Monterey the hills are covered with a forest of the Mon- 
terey pine, which also occupies much of the lowland adjacent to 
the shore, where it mingles with the cypress, which occurs only 
close to the shore, often clinging to the very edge of the rocky 
headlands. 

In the loose sandy soil between the pines is a more or less dense 
chaparral formation in which Ceanothus and manzanita (Arc- 
tost aphylus) are perhaps the commonest shrubs, but with these 
are a number of others, including several species of currants, 
goose-berries, cascara and others. 

The outer coast ranges, from the Oregon boundary to Santa 
Cruz, are characterized by the redwood formation. The redwood 
reaches the greatest development in its northern range, Humboldt 
and Del Xorte counties. The Humboldt forest is sometimes a pure 
stand of redwood, where the huge trees, sometimes more than 300 
feet high, grow so closely together that on account of the dense 
shade, there is very little undergrowth except ferns, and a few 
low evergreen shrubs. 

So far as known, the redwood exceeds all other trees in height, an 
authentic measurement being 342 feet. Occasionally trunks 15 to 
20 feet in diameter are met with. 



THE NORTH TEMPERATE ZONE 



139 



The redwood formation reaches its maximum development 
along the Eel River, south of Eureka, about latitude 40°. In 
places there is a pure stand of these enormous trees, many of 
them more than 300 feet in height, and probably the heaviest 
stand of timber in existence. 

Between Eureka and the Oregon line, a region of extremely 
heavy rainfall, the redwood is replaced gradually by the tideland 
spruce, hemlock, and a fir, Abies grandis. This forest has a 
dense undergrowth of almost tropical luxuriance. The ground 




Fig. 38. — Grove of Monterey cypress; Monterey Peninsula. 



is carpeted with ferns, and there is an abundant growth of rhodo- 
dendrons, evergreen barberries and huckleberries, dogwood, and 
alders, and a variety of other shrubs and small trees. 

In the southern redwood belt the Douglas fir is common, as 
far south as the Santa Cruz Mountains. 

The main body of redwood is confined to the coastal mountains 
north of San Francisco; but there are fine redwood forests in the 
Santa Cruz mountains, and smaller growths in the sheltered 
coastal canyons of the Santa Lucia mountains south of Monterey. 

The range of the redwood is controlled by the summer coastal 
fogs. Only where these reach does the redwood naturally flourish, 



140 OUTLINE OF PLANT GEOGRAPHY 

apparently requiring the protection of the fog-blanket against 
the hot sun of the rainless summer. In the mixed redwood forest 
of central California there are several characteristic broad-leaved 
evergreen trees. The tan-bark oak and madrono have already 
been mentioned and in addition to these are the mountain live 
oak (Qvsrcus chry sole pis), an evergreen chestnut (Castanopsis), 
and the beautiful bay-tree (Umbellularia). Black oak (Quercus 
Kelloggii) and the big-leaved maple, are the most important 
deciduous trees, but along the streams are large alders, cotton- 
woods, willows, and the box-elder {Acer Negundo). 

A dwarf yew (Taxus brevifolia) and the " nutmeg" {Torreya 
Calif arnica), also of the yew family, are sometimes found in the 
redwood forest. Torreya has its only other American representa- 
tive in Florida. 

Of the attractive shrubs of the redwood forest, the most beauti- 
ful are the pink rhododendron {R. Calif or nicum), and the azalea 
{R. occidentale) . The former is mainly confined to the north, and 
is restricted to the coastal region, while the azalea has a wider 
distribution. Evergreen huckleberries and barberries are abun- 
dant, and the big white-flowered thimble-berry {Rubus Nutkanus), 
pink-flowered currants, blackberries, Spiraea, and roses, are 
characteristic. 

Among the common woodland flowers are Trillium, Ery- 
thronium, Fritillaria, Clint onia, violets and cress (Cardamine, 
Dentaria), Smilacina, Aquilegia, Cynoglossum, Delphinium and 
many others. Ferns are abundant, but there is no great variety. 
Adiantum pedatum, Woodwardia Chamissoi, Aspidium munitum, 
are perhaps the most striking. 

Central California is a meeting place for the northern and south- 
ern floras. This is very well shown in the region about Stanford 
University in the Santa Clara Valley, about thirty miles south 
of San Francisco. To the west are the Santa Cruz mountains, 
the highest points rising about 3,000 feet above the valley. The 
sheltered valleys, which are accessible to the sea-fogs, have a fine 
growth of redwoods, some of great size, and with them are the 
usual associates, Douglas fir, tan-bark oak, madrono, laurel, etc. 

These mountains, all through the summer, get the ocean fogs 
which drift into the redwood canyons, but rarely reach the valley 
floor, except occasionally as "high fog." 



THE NORTH TEMPERATE ZONE 141 

These cool, moist coast mountains harbor many plants ev- 
idently of northern origin, such as violets, trilliums, lilies, anemones, 
Erythronium, roses, elders, and many others. While these genera 
are wide-spread boreal ones, the species are mostly peculiar. 

On the valley side of the mountains the character of the vegeta- 
tion is very different. While redwood is still found in places, the 
forest is mainly an open one in which oaks predominate, partly 
the deciduous black oak (Quercus Kelloggii), partly live oaks. 
Madrono, bay, and buckeye {Aesculus Californica), also occur, as 
well as other trees and shrubs. 

The dry slopes are covered with chaparral made up of a variety 
of shrubs and small trees, mostly evergreen, but including a good 
many deciduous species. Several species of Ceanothus, with 
white or blue flowers are abundant and very ornamental, and 
known locally as "wild lilac." Manzanita (Arctostaphylos) is 
also represented by several species. These two genera are remark- 
ably developed in Pacific North America. Several species of scrub 
oaks, buckeye, Garrya, " poison oak" (Rhus diver siloba) , "Yerba 
santa" (Eriodictyon), Adenostoma, bush-poppy (Dendromecon), 
several species of Ribes, as well as the more familiar roses, black- 
berries, and elder, are common constituents of the chaparral. 

The valley itself is open, and except on the north slopes of the 
foot-hills, is scantily wooded. Groves of picturesque, spreading 
oaks, however, give the landscape a park-like aspect that is very 
attractive. The commonest oaks are the live oak (Q. agrifolia) 
and the white oak (Q. lobata). The latter under favorable condi- 
tions reaches a gigantic size, hardly rivalled by any other species. 
Less common in dry soil, is the blue oak (Q. Douglasii). 

In general, both the woody plants and the herbaceous vegetation 
of the valley, are of southern rather than northern affinities, and 
are related more or less closely to the flora of the northern Mexican 
plateau, which really comprises southern California and Arizona. 

The coastal mountains of southern California are much drier 
than those of the north, and except in the canyons are largely 
bare of trees, the southern Californian forests being mainly re- 
stricted to the higher elevations of the interior mountains. Along 
the coast and in the interior valleys, the rainfall is scanty, and 
much of the country is too dry for tree-growth, and some of it is 
genuine desert. 



142 OUTLINE OF PLANT GEOGRAPHY 

Inside the coast ranges are many valleys, great and small, by 
far the most important being the great central valley drained by 
the Sacramento and San Joaquin rivers which unite and discharge 
into the Bay of San Francisco. This great valley is a vast plain 
some 400 miles long, and over 50 miles wide in places. Much of 
this is treeless, recalling the mid-western prairies, and is a region 
of great fertility, which under irrigation has become very produc- 
tive. Numerous smaller valleys, also highly fertile, occur in both 
northern and southern California. 

The valleys and foot-hills are largely covered with annual 
grasses, which die at the beginning of the long diy summer, this 
being the period when much of the native vegetation is dormant. 
As soon as the first heavy rains come, usually in October or No- 
vember, the grass-seeds quickly germinate, as well as those of 
many other annuals, native and introduced, and the landscape 
changes from brown to vivid green, to last through the winter and 

spring. 

The annual grasses which are so abundant in the valleys of 
California, are mostly species introduced from southern Europe. 
The most conspicuous of these is the wild oat (Avena fatua) , which 
is very common, and furnishes valuable forage. The native grasses 
are mostly perennial bunch-grasses, e. g., Stipa spp., Danthonia 
spp., Bouteloua spp. 

There is a great variety of showy annuals which in favorable 
seasons cover the hillsides and meadows with masses of splendid 
color. Many of these are familiar in cultivation, e. g., Nemophila, 
Gilia, Eschscholtzia, Phacelia, Lupinus, Godetia, Clarkia, etc., 
but there are many others, especially such showy Compositae as 
Layia, Baeria, and others like Orthocarpus, which are not so well 
known. Perhaps the showiest of all, and almost the commonest, 
is the California poppy, Eschscholtzia Californica, which forms 
solid masses of blazing orange sometimes acres in extent, and often 
associated with patches of brilliant blue lupins, almost as showy, 
and produced in equal profusion. 

With the annuals are associated a number of perennials, largely 
tuberous or bulbous species. Buttercups, mallows (Sidalcea), 
a large yellow composite (Wyethia), various Umbelliferae, and 
especially a variety of liliaceous species, as well as species of Iris 
and Sisyrynchium. 



THE NORTH TEMPERATE ZONE 143 

Ten species of true lilies are found in California, including some 
of the finest of the genus. These are mostly mountain species, 
or in the coastal region growing in the moist canyons, or forest. 
The Humboldt and Washington lilies of the Sierra Nevada, and 
the redwood lily (Lilium rubescens) are especially beautiful. 

In the northern part of the state are several fine species of 
Erythronium, a genus which reaches its finest development in 
the northern Pacific States. 

Especially beautiful are the many species of Calochortus, "Mari- 
posas," " butterfly-tulips," the majority of which are confined to 




Fig. 39. — Death Valley. Photo., Dr. W. S. Cooper. 

California. Another common and attractive genus is Brodiaea 
(now split up into several genera), with umbels of white, blue, or 
yellow flowers. Allium, Chlorogalum and Zygadenus are other 
common genera of Liliaceae. Of the Iridaceae, the genus Iris 
has a number of common and handsome species, and the showy 
Sisyrinchium helium is one of the most abundant spring flowers in 
central California. 

A feature of the Californian flora is the great number of species 
within some genera, as well as the large number of endemic 
genera, sometimes monotypic. Of the former, Trifolium, Lupinus, 
Calochortus, Mimulus, Pentstemon, may be cited; of the latter, 
Platystemon, Romneya, Bloomeria, Brevoortia, Limnanthes, 



144 OUTLINE OF PLANT GEOGRAPHY 

Pickeringia, Chamaebatia, Adenostoma, Bolandra, Carpenteria, 
Eucharidium, Hemizonia, and many others. 

The inner valleys of southern California are as a rule arid, and 
often actual deserts. South of the Tehachipi Mountains, which 
form the southern boundary of the great central valley, lies the 
Mojave desert, which is a plateau of 3,000 to 4,000 feet elevation 
toward the west, but descending on the east to the Colorado River. 
To the southeast lies Death Valley, a region of intense heat 
which lies more than 300 feet below sea-level and is the lowest 
point in the United States. 

In the more elevated portion of the Mojave desert, which is 
traversed by the railway, the traveller's attention is at once 
attracted by the fantastic tree-yuccas (Yucca brevifolia), scattered 
over the landscape. With these are found in places scrub junipers 
and some other shrubs. Cacti are scarce, in marked contrast to 
the Colorado desert to the south, which is separated from the 
Mojave by the San Bernardino mountains. 

In the Mojave the predominant shrub is the creosote-bush 
(Larrea Mexicana) , also a feature of the Colorado desert. With it 
are associated a number of other characteristic species, e. g., Fran- 
seria dumosa, species of Atriplex, Opuntia, Ephedra, Euphorbia, 
Lepidium, Gilia, Eschscholtzia and others. 

Along the Mexican boundary. in southeastern California and 
Arizona, is the Colorado Desert, a region with a vegetation dis- 
tinctly Mexican in type, which will be discussed more in detail 
later. 

While the floor of the great valley is largely destitute of trees, 
especially in the southern areas, the banks of the rivers and smaller 
streams are more or less heavily wooded. Sometimes, as along 
parts of the Sacramento, extensive bottom lands are developed, 
which support a quite heavy forest of large cotton-woods, and 
elsewhere along the streams are willows and alders. 

Sometimes the western sycamore (Platanus racemosa) is found 
along the stream-banks, especially toward the south, and the 
box-elder (Acer Negundo) is a common and wide-spread species. 
Less common is the Calif ornian walnut (Juglans Calijornica). 
Roses, blackberries, poison oak (Rhus), dogwood, button-bush 
(Cephalanthus) are the commonest shrubs of the stream-side 
thickets. 



THE NORTH TEMPERATE ZONE 



145 



Marshes are not especially characteristic of the Californian 
coast, but in the delta lands of the Sacramento and San Joaquin, 
are extensive tracts of marsh-land, through which the railway 
between San Francisco and Sacramento passes. These "Tule 
marshes" are largely almost pure associations of bulrushes (Scirpus 




Fig. 40. A 

A. Coniferous forest, Mt. Shasta region. 



B. Azalea (A. occidcntalis) . 



spp.). together with cat-tails and other characteristic marsh 
plants in the more open places. 

The accumulation of vegetable matter builds up islands of 
peaty humus soil, which support many plants, some quite charac- 
teristic of the marsh region. When drained, the delta lands are 
extremely productive, and of great value. 

Extending from the Oregon line to southern California, the 
lofty range of the Sierra Nevada forms California's eastern bound- 



146 OUTLINE OF PLANT GEOGRAPHY 

ary. The range is less definite at the north, merging into the 
Cascades of southern Oregon. Southward from Mt. Shasta it 
is more clearly defined and forms the eastern boundary of the 
great central valley. The mountains rise rapidly from the level 
valley floor, and as one ascends, a marked change is noted in the 
vegetation. 

Along the upper Sacramento, and in the vicinity of Mr. Shasta, 
the Douglas fir is the commonest tree, and the general type of the 
moist forest is much like that of Oregon and Washington. The 
flowering dogwood and vine-leaved maple are common and along 
the Sacramento river one sees bushes of syringa (Philadelphus), 
and Calycanthus. This region is the home of the Calif ornian 
pitcher plant (Darlingtonia). 

The foot-hills of most of the great valley are grass covered, and 
with an open growth of oaks, buckeye, and various shrubs, often 
forming chaparral formations of greater or less extent. The chap- 
arral shrubs are much the same as on the coast ranges, e. g., Man- 
zanita, Ceanothus, Rhus, Ribes, Rhamnus, Eriodictyon, etc. 

The first conifers to appear are " digger-pines " (Pinus Sabi- 
niana), curious thin-leaved, gray open-branched trees, characteris- 
tic of the dry belt which in parts of the range occupies the slopes 
above the lower foot-hills. 

At about 2,500 feet the yellow pine (P. yonder osa) begins, and 
at about 4,000 feet in the middle Sierra, one enters the magnificent 
belt of mixed coniferous forest, which is perhaps without a rival 
anywhere in the world. 

Below this zone, and sometimes extending into it on dry and 
exposed slopes, are extensive chaparral formations made up of 
a good many species. Manzanita (Ardostaphylos spp.), Ceano- 
thus, scrub oaks and chinquapin (Castanopsis) are the most 
abundant chaparral shrubs, but there are a good many others 
mixed with these. Among the less common but very showy shrubs 
may be mentioned Fremontia Calif arnica (Sterculiaceae), with 
big yellow flowers, and the rare Carpenteria Calif arnica with 
very handsome white flowers. This chaparral covers great ex- 
panses of the dry mountain slopes and is often quite impenetrable, 
the tough interlacing branches making an impassable thicket. 

At about 4,000 feet, the main forest zone begins. This is well 
shown in the Yosemite valley. At this elevation the yellow pine 



THE NORTH TEMPERATE ZONE 



147 



is the most abundant tree, and reaches its finest development. 
Some of the trees exceed 200 feet in height with a diameter of five 
to six feet, or even more. 

Higher up, especially where there is abundant moisture, the 
yellow pine is less in evidence, and at about 6,000 feet, the white 




/ 

-N 




Fig. 41. — Yellow Pine (Pinus ponderosa). 
A. Yosemite Valley. 



B 

B. Shasta Springs, 
Northern California. 



fir (Abies concolor) is the commonest species in the regions where 
the giant Sequoia (S. gigantea) is found. The latter, unlike the 
coast redwood is never predominant in the forest, but occurs in 
small groups, or singly, in a forest made up mostly of other trees. 
These in the most important grove, the Giant Forest, are princi- 
pally white fir, and sugar pine; but in the drier and more exposed 



148 



OUTLINE OF PLANT GEOGRAPHY 



places, yellow pine and incense cedar (Libocedrus decurrens), also 
are found, and above 6,000 feet, the red fir (Abies magnified). 
These are all trees of the first rank and this coniferous forest is 
quite unrivalled. 

Next in size to the sequoias, is the great sugar pine, the largest 
of all pines, and a notable tree from southern Oregon southward. 




A B 

Fig. 42. — Sugar Pine (Pinus Lambertiana.) 
A. Yosemite. B. Shasta Springs. 

In habit it resembles the eastern white pine, but greatly exceeds 
it in size. The cones, also, are notable, as the longest of any conif- 
erous tree. 

This great forest depends for its water supply mainly upon the 
very heavy snow-fall, as little or no rain falls during the summer. 
As the snow melts many attractive herbaceous plants appear, 



THE NORTH TEMPERATE ZONE 



149 



and the woods and moist meadows are adorned throughout the 
summer with a great variety of beautiful flowers, many of them 
related to those of the Rocky Mountains, but a large number are 
peculiar to California. Among the latter is the curious "snow- 
plant" (Sarcodes sanguined) related to the Indian-pipe of the 
eastern states, but sometimes a foot high, and with a large 
raceme of blood-red flowers. 

In the lower forest zone, 
there is an undergrowth of 
deciduous trees, oaks, maples, 
and the showy flowering 
dogwood (Cornus Nuttallii) . 
There are also many showy 
shrubs, like the syringa (Phil- 
adelphus Lewisii) and the 
azalea, which is extremely 
abundant and beautiful in 
the Yosemite. 

Most of the deciduous trees 
disappear at the higher eleva- 
tions, and the forest is exclu- 
sively coniferous, and certain 
Rocky Mountain species, e. g., 
lodge-pole pine, western white 
pine (Pinus monticola) are 
associated with the Pacific 
coast species. At timber line, 
the alpine white pine (P. albi- 
caulis), and a large juniper 
(Juniperus occidentalis) , are 
found. 

On the rocks and in drier soil are many showy flowers: blue 
Pentstemons, forget-me-nots (Lappula), and lupins; scarlet Gilias, 
pink Spraguea, yellow Wyethia, looking like dwarf sun-flowers, 
little pink and yellow Mimulus and others. In the wet moist 
meadows are masses of blue Camassia and pink shooting-star 
(Dodecatheon), white marsh marigold (Caltha) and white violets, 
and somewhat later white orchids (Habenaria leucostachys), 
blue monkshood and larkspur, gentians, mimulus, scarlet Castil- 




Fig. 43. — False hellebore (Veratrum Cali- 
fornicum) . Lake Tahoe. 



150 



OUTLINE OF PLANT GEOGRAPHY 



l,ia. and the small tiger-lily, L. parvum. The tall false hellebore 
(Verairum Ccdifornicum) is a very striking and common plant, 
and in the late summer the meadows are gay with asters, golden- 
rod, Gaillardia, and others reminiscent of the northern prairies. 




Fig. 44. — Ceanothus sp., a characteristic chaparral shrub, Mt. Shasta region. 



The true alpine flora of the Sierras is much less developed than 
on the snow-clad peaks of the Cascades and Rockies; but there are 
a good many of the same, or closely related species, of Primula, 
Phlox, Silene, Gentiana, etc. 

The flora of the Shasta region of northern California resem- 
bles to some extent that of the Cascades, rather than the Sierra. 
While both yellow and sugar pines occur, the commonest tree is 
the Douglas fir, which is found also in the Sierra forest, but in 
much smaller numbers. Where moisture is abundant the beauti- 
ful Lawson cypress (Chamaecyperis Lawsoniana) also occurs near 
Mt. Shasta, and deciduous trees, oaks, maples and dogwood, are 
much in evidence. On springy hillsides, which are a feature of 
this region, are many flowers which recall the northern woods. 

Columbine, bleeding-heart (Dicentra), monkshood, spring- 
beauty (Claytonia) and tiger-lilies (L. pardalinum) , grow in the 
wet mossy ground, with ferns of several species. Thimble-berry 
(Rvbus X nth-anus), and cow-parsnip, with its huge leaves and great 
umbels of white flowers are prominent in this plant formation. 



THE NORTH TEMPERATE ZONK 



151 



In this region is found the remarkable California]] pitcher 

plant (Darlingtonia Calijornica), reminding one of the tall Sar- 
racenias of the Gulf states. A number of orchids, Cypripedium, 
Epipactis, Cephalanthera and others are also characteristic of 




A B 

Fig. 45. — A. Californian pitcher plant (Darlingtonia Calif orniea), Shasta region, 
California; B. Giant saxifrage (Saxifraga peltata), Upper Sacramento River; 
Azalea in background. 

this region. In general the Californian flora is not rich in orchids. 
Many boreal plants, e. g., Linnaea, Clintonia, Pyrola, etc., are 
common in the woods of this district. 

The Colorado Desert 

Southeastern California and southern Arizona, the regions 
adjacent to the Colorado River, are very arid, much of the country 
being a true desert. Part of this region, like the Imperial valley, i 
below sea-level, and a region of intense summer heat . The less 



1 52 



OUTLINE OF PLANT GEOGRAPHY 



arid portions of this desert develop an extremely interesting 
vegetation, in which Cacti play an important role and comprise 
numerous species, ranging in size from the low-spreading prickly- 
pears and little melon-cacti, to the giant Suarro (Cereus giganteus), 




Fig. 40. — "Ocatilla" (Fouquiera splendens), Colorado desert. 
Photo., Dr. W. S. Cooper. 



whose huge fluted columns are sometimes 30 to 40 feet high, and 
the most conspicuous objects in the desert landscape. 

Creosote-bush (Larrea), Palo-verde (Parkinsonia), and the ex- 
traordinary Ocatilla (Fouqwira splendens) are also characteristic 
of this region. The latter consists of a cluster of unbranched 
slender stems, 8 to 10 feet long, bearing small bright green leaves 
at times, but mostly quite bare. In the spring each wand is tipped 
with a cluster of bright red flowers. 

In seasons of heavy spring rains, the ground is covered for a 
brief period with a carpet of showy flowers, but these soon dis- 
appear with the intense dry heat of the desert summer. 

In the vicinity of the Colorado desert are found the only native 
1 difornian palms. Rising abruptly from the desert to a height 
of 10,000 feet, the San Jacinto mountains have at their base 
canyons opening on the desert. Some of these are watered by 

reams which lose themselves in the desert sands, but the floor 
of the canyons is permanently moist. 



THE XORTEI TEMPERATE ZONE 



153 



Entering one of these canyons from the Bandy desert outside, 

is like being transported to the tropics, for instead of cactus and 
creosote-bush, there are groves of tall fan-palms growing luxu- 
riantly in the moist bottom of the canyon, an extraordinary con- 




Fig. 47. — California fan-palm (Washingtonia filifera), Stanford 
University. Photo., Dr. L. L. Burlingame. 

trast to the desert vegetation, only a few rods away. Tins palm. 
Washingtonia filifera, is very common in cultivation in California, 
and other countries of similar climate. 

Southern California, Arizona, New Mexico anil western Texas, 



154 



OUTLINE OF PLANT GEOGRAPHY 



originally Mexican politically, belong botanically to the northern 
Mexican botanical province. The flora of this region is a typical 




Fig. 48. — Desert vegetation, Arizona. Nolina sp., Yucca sp. 
Photo., Dr. W. S. Cooper. 







Fiq. 49. Mountain forest, Arizona. Photo., Dr. W. S. Cooper, 



xerophytic one, and is very rich in species, mostly belonging to 
strictly American genera; indeed as a whole, this flora is perhaps 
the most exclusively American of any region. First in importance 








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155 



L56 OUTLINE OF PLANT GEOGRAPHY 

are the ( Jacti, which reach their maximum development in Mexico, 
as do most of the genera found in the states adjacent to Mexico. 
Al'oui Tucson, in southern Arizona, the desert flora is a rich one, 
embracing many species of Cacti, Fouquiera, Agave, Ephedra, 
Larrea, mesquit (Prosopis), and others. Most of the species of 
Yucca belong to this north Mexican region, as well as the species 
of Agave, of which the century plant is sufficiently familiar. It 
has been thought ] that these peculiarly American forms originated 
in northern Mexico, and have migrated from this centre both 
north and south. 

Of the more than 1,000 species of Cacti the greater number are 
Mexican, and the same is true of Agave. Of the latter, 140 species 
are found in Mexico, while only 24 are known elsewhere. 

The Mexican plateau region differs from that of the Pacific Slope 
in a different distribution of rain, having a marked rainy season 
in summer. This has an evident effect on the distribution of certain 
plants. The Cacti, especially, are adapted to utilizing the summer 
>howers, and are rare, or wanting in those parts of California 
where summer rains are absent. This difference in rainfall is 
probably largely responsible for the absence or scantiness, of 
certain Arizona species in southern California. 

South of the dry Mexican plateau the rainfall is heavier, and the 
mountains are clothed with forests much like those of the adjacent 
L'nited States. Evergreen oaks, pines, and other northern trees, 
are the principal constituents of the north Mexican mountain 
forests. 

1 Harshberger, loc. cit., pp. 298-300. 



CHAPTER VI 

THE PALAEOTROPICS 

AFRICA AND CONTINENTAL ASIA 

As we have already seen, the tropical floras of the two hemi- 
spheres differ far more from each other, than do those of the 
boreal zones. 

In the eastern hemisphere (Palaeotropics), there are two 
distinct floras, the African and Indo-Malayan, which occupy 
widely separated regions, and are very different from each other. 
The American tropics (Neotropics), form a single geographical 
unit, and the flora is much more homogeneous. 

Tropical Africa 

Much the greater part of Africa lies within the tropics, the 
Tropic of Cancer passing through the centre of the Sahara, while 
the Tropic of Capricorn lies only about 12° north of the Cape of 
Good Hope. In spite of the latitude, however, only a relatively 
small part of Africa exhibits the climatic conditions usually 
associated with the tropics. 

The topography of the great African continent is peculiar. 
For the most part there is a gradual rise from the coast, sometimes 
in broad terraces, to a great central plateau, with relatively little 
land at sea-level. This is less marked in the equatorial regions of 
the West Coast where there is a development of the rank forest 
growth characteristic of the wet tropics, not shown to any greal 
extent elsewhere in Africa. 

While the greater part of the continent consists of table lands. 
the elevation of these is moderate (1,000—2,000 metres), and the 
high mountains, like Kilimanjaro and the great Kamerun, are 
generally more or less isolated masses rising from the much lower 

table land. 

This elevation of the general mass of the continenl of course 
involves a decided lowering of the mean temperature of the plateau 

157 



s 

s 

sin Dm 

\ tare < 

g 

ta- 
gtheS to 

. ^ ; - \ .ran 1 

ho 
s sof 1 - S I thfts 

:—.:_.-. -. swanks and juntos of th< Guinea eocvs:. Cor.co basin 

K 

grass 

I as - . . - 

TV s | ss >r prairi 

s res S ■ - - 

ides g ws in which the 

JCUe takes its ris - sare in more i 

tral 

sisofg Doeinms 

c ■ ~ g amount 

-ica. 

v.: - - a 

Kgrteu 

TV s ^ has 

I han 



THE 

likely th y ha 

■ 

I: • ■ istal I wer *1 

• 
A -t Af 

rivers, and a] .da 

i vast 

OWUY, 

to it oJ mud ons a 

gradually shut, off from >.l water, arid bj 

grove fo ... \ .. i a belt which gr 

ually lid Ian 

JTie outer . the swamp i imposed the 

-.:::.'• -p<-':i<--. of ::. :.:.f.'.'0'. '<: I:K.zoph//ra mar>/jU ■..-. v. * •.:. w- 

i the 
species c wee of the Indian Ocean. I inland * 

"white mangrove" .U>.o 

also occurs in * *1 America, biri ie eastern tr 

Two species r 

pn* £ v thickets b angrove forma- 

bandsom rn, At ommon in 

similar sftual -*, gro*. 

Between the mang formation and the ra 

and partly reclaimed from the swamp, but wr ongly 

saline soil in which a numb* irubs and small 

trees grow. og gler r to W 

Cae#; / » climber, a- lso 

! curious leafless Cozxytha f&ijrrrmiz, which much resembles 
do but fc the laurel family. Theft 

p. o grow ' g the coa- 

1 Engler. fee. cit., p. Ifc 



1G0 OUTLINE OF PLANT GEOGRAPHY 

From the Niger delta to the Congo, the mangrove swamps 
are developed od an enormous scale. 

The Wesl African rain-forest reaches its greatest develop- 
ment in Kamerun, where rich volcanic soils combine with an 
equatorial climate to produce a maximum luxuriance of vegeta- 
tion; but the whole coastal region from the Niger to the Congo 
has a very heavy forest. 

The country rises rapidly back of the coast, and the forest 
is largely restricted to the regions bordering the great rivers 
which descend from the interior, while much of the inland country 
is open grass-land or savanna. 

Back of the coastal belt of mangroves is a strip of " alluvial 
forest," composed of a variety of trees, shrubs, and climbing 
plants, but having only trees of moderate size. 

Almost the first tree to invade the new land, is a screw-pine 
(Pandanus candelabrum). The screw-pines are all palaeotropic, 
and are very characteristic of the strand floras, although by 
no means restricted to the coastal regions. Their curious stilt- 
like roots and spirally set sword-shaped leaves are a familiar 
sight in the tropics of the old world, and they are not uncom- 
mon in cultivation. 

Several species of palms are characteristic of the alluvial forest. 
Among these are a wild date (Phoenix spinosa) and the wine- 
palm {Raphia vinifera), as well as rattan-palms, climbing species, 
whose thorny stems and leaves are a terror to the explorer. With 
these are associated species of low-growing trees and shrubs, 
belonging to many families, but with Leguminosae most abun- 
dant. Climbing plants of many sorts abound, as they do every- 
where where light is sufficient. 

Characteristic of the whole coastal zone is the oil-palm (Elaeis 
Guieneensis) , which grows wild, but is also extensively planted. 
This yields the palm-oil, such an important article of commerce. 
The oil-palm is a very handsome tree, often seen in cultivation 
in tropical countries. It has enormous feathery leaves, and 
the persistent leaf-bases, and rough stem offer a very favorable 
attachment for orchids, ferns and other epiphytes. 

The alluvial, or border forest, passes gradually into the high 
rain-forest in which the variety of trees is very great, and many 
of them attain gigantic size. The trees are very tall, and the 



THE PALAEOTROPICS 161 

interior of the forest is so densely shaded that very little under- 
growth is developed, and such species as occur are able to exist 
with a minimum of light. 

This forest interior has been very graphically described by 
Miss Kingsley. 1 The giant, smooth gray or red trunks form 
huge pillars, sometimes a hundred feet high, or more, before 
branching to form the roof of this great temple. There are few 
epiphytic growths, except high up in the crowns of the tr< 
and the huge lianas which swing from tree to tree are quite bare 
until they reach the light above the dense canopy of foliage. 

The most important of these lianas are several species of Lan- 
dolphia (Apocynaceae) which yield most of the West African 

rubber. 

Where light is admitted, as when trees are blown down by 
tornadoes, which often devastate these regions, or in clearings 
made by the lumberman, or along the banks of the rivers, the 
forest presents a very different aspect. In such situations there 
is an amazing luxuriance of vegetation, the lofty trees being clothed 
from top to bottom with epiphytes and a great variety of lianas. 

Some of these vines, e. g., QuisquaUs indica, Clerodendron 
splendens, Solatium sp., as well as certain trees, have showy 
flowers, which in their season relieve the monotony of the uniform 
green of the rain-forest. 

The number of species of trees in this great forest is very lai e 
and only a few of the more characteristic ones can be mentioned. 2 

As in most tropical forests, the Leguminosae are abundant, and 
some of them reach enormous size. Giant figs are also a feature 
of the forest. The latter often begin life as epiphytes perched on 
a branch, or in a crotch of some tall tree, near the light. The 
young fig sends its roots downward, and these completely encircle 
the parent tree, which is finally strangled, leaving the fig with 
its crown supported by a huge hollow trunk formed of the <•< .ales- 
cent roots. These "strangling figs" occur in the rain-forests of 
both hemispheres. 

Some of the giant trees of West Africa are of great value for 
their timber. These include several species of mahogany and 

1 Mary H. KinRsloy, Travels in West Africa, pp. 26] 262, 1897. 

2 For a very full account of the vegetation of tin* region aee Engler, loe. cit., 

Vol. I, Pt. II. 



162 OUTLINE OF PLANT GEOGRAPHY 

ebony, the latter related to our persimmon. Among the notable 
trees are species of silk-cotton (Ceiba, Bombax), trees of the largest 
size, with enormous buttresses supporting the huge trunks. Other 
trees belong to the nutmeg family (Myristicaceae), and the 
Euphorbiaceae have numerous representatives. 

Some of the t rees exceed 200 feet in height, and among them are 
species with showy flowers, which, however, are quite invisible to 
the wanderer in the forest floor beneath. Among the best known 
of these is Spathodea campanulata, related to our Catalpa and 
trumpet creeper, whose big orange-scarlet bell-shaped flowers are 
very handsome. This tree is quite common in cultivation through- 
out the tropics. 

Where the light is sufficient there is a heavy undergrowth of 
herbaceous plants. Some of the Araceae, and Scitamineae (gingers, 
Cannas, bananas, etc.) are especially conspicuous and the ponds 
and shallow river margins show a profusion of aquatics: sedges, 
water-lilies, pond-weeds, etc. Some of the climbing Araceae are 
very conspicuous, as they are in nearly all wet tropical regions. 

The Scitamineae include several species of true bananas (Musa), 
distributed over tropical Africa, in addition to the many cultivated 
varieties of plantains and bananas. The gingers (Zingiber, Costus, 
etc.), are extremely abundant in the wet districts, and Canna 
indica is a common weed, as it is in many countries w r here it has 
been introduced from America. 

Of the sedges, the famous papyrus (Cyperus Papyrus) is abun- 
dant in many other parts- of tropical Africa, as well as in the Nile 
district. 

Compared with the equatorial regions of America and Indo- 
Malaya, the West African forest flora is relatively limited in 
extent and poor in species, especially in such very characteristic 
types as the palms and orchids, both of which attain their max- 
imum development in the American and eastern tropics. This 
is true also of the Araceae. 

A remarkable result of the more recent studies in the flora of 
equatorial West Africa is the demonstration of unmistakable 
relationships with tropical America. Engler * gives a long list 
of genera and species peculiar to West Africa and America, or 
predominant in these regions. Examples of these are the two 

1 Loc. cit, pp. 984-980. 



THE PALAEOTROPICS L63 

common mangroves, the wine-palm, and a species of oil-palm 
(Elaeis), as well as many others. Engler concludes thai there must 

have been more or less complete land connections between South 
America and Africa, at some earlier period. 

Much of the more elevated portions of tropical Africa is occupied 
by grass-land and open forest or savanna, with a sub-tropical 
rather than tropical climate. The grass flora is a very rich one and 
is a very important constituent of the African vegetation, much 
of the " veldt" in the Transvaal and Rhodesia looking quite like 
the prairies of the western Mississippi valley and Great Plain-. 
These grasses comprise many such wide-spread genera as Andro- 
pogon, Panicum, Paspalum, Agrostis, etc., but tropical Africa pos- 
sesses a considerable number of genera, either strictly endemic or 
majnly African. Examples of these are Beckera, Perotis, Schmid- 
tea, Chaetobromus. 1 

In addition to the numerous grasses of the open plains and 
savannas, there are giant grasses like the common reed (Phragmites 
vulgaris) and various bamboos; and the wild sugar cane (Sac- 
charum spontaneum) is common in many places. A good many 
grasses, like the bamboos and many smaller species, are found in 
the wet forest, and such forest grasses usually have soft and rel- 
atively broad leaves. 

Tropical East Africa 

The equatorial portion of the East coast offers a marked con- 
trast to the opposite side of the continent. Nowhere, at sea-level, 
is the rain-forest developed, and only back of the coast, at the base 
of the mountains which intercept the rains which pass over the 
immediate coast, is a rain-forest encountered. It is much less 
luxuriant than the west coast forest both because of the limited 
extent of the area of heavy precipitation, and because a large 
part of the forest has been cleared for agriculture. 

As one sails along the East African coast the shore for the most 
part shows a sandy beach. Mangrove swamps are found where 
rivers discharge, as at Beira in Portuguese East Africa and other 
points along the coast, and in places, back of the shore are hills 
clothed w r ith forest; but the trees are mostly deciduous, and in 

Angler, loc. cit., p. 902. 



164 



OUTLINE OF PLANT GEOGRAPHY 



October, when the writer made this trip, being the dry season, 
they were mostly bare with only a few evergreen species like some 
of the figs. 

The most remarkable tree of this region, but wide-spread in 
central Africa, is the Baobab (Adansonia digitata). These trees, 
with their huge ungainly trunks, and wide-spread naked limbs were 
much the most conspicuous trees of this east coast. The leaves 









Fig. 50. — Coast, tropical East Africa. Coconut palms, baobab. 

of the baobab are somewhat like those of the horse-chestnut, and 
the flowers, and later the big fruits, hang vertically from long slen- 
der stalks. 

The mangrove formations are relatively limited in extent, and 
not comparable with the immense coastal swamps of West Africa. 
They are also inferior in the size of the trees. The eastern man- 
grove, Rhizophora mucronata, is a much smaller tree than R. 
Triangle of the west coast. 

From the excessively wet coastal districts of equatorial West 
Africa, there is a rapid falling off in precipitation both north and 



THE PALAEOTROPICS 



L65 



south. The delta region of the Congo, is much drier than the 
Kamerun coast, and in much of Portuguese West Africa, and the 

* 

former German West Africa, desert condition- prevail, even at the 
coast. North of the Gulf of Guinea, there is a similar diminution in 
rainfall until in Senegal, and especially in the western Sahara, 

desert conditions are encountered. 

The coastal region of Angola (Portuguese West Africa), from the 




Fig. 51. — Baobab, Mombasa, British East Africa. 



Congo southward, is a dry plain with characteristic xerophytic 
vegetation, scattered shrubs and stunted trees, with an occasional 
baobab. The commonest tree is Sterculia tomentosa. With th< 
are found Aloes, the curious cactus-like Euphorbias, so characteris- 
tic of South Africa, and Sansevieria qjlindrica, a liliaceous plant 
with stiff, rush-like leaves. 

The vegetation changes, however, as soon as the hilly country, 
some 30-40 miles from the coast, is reached. Here there is a 
forest growth of both deciduous and evergreen specif-. 1 

1 Engler, loc. cit., pp. 623-24. 



L66 OUTLINE OF PLANT GEOGRAPHY 

At higher altitudes in the mountains there is a marked increase 
in rainfall, and in the valleys and more sheltered situations, 
a true rain-forest is developed. 

Further south the coast is very arid, and finally true desert 
conditions prevail. 

The most remarkable plant of this district is the extraordinary 
Tumboa (Welwitschia) which has no near relatives elsewhere. 
It belongs to the small order Gnetales, which in some respects 
is intermediate between the true gymnosperms (conifers and 
cycads), and the higher flowering plants. Welwitschia has a short 
woody trunk which sends a long tap-root deep into the ground, 
and bears two great persistent, strap-shaped leaves, generally 
split into ribbons, which are all the plant ever develops. This 
desert coast region is continuous with the great Kalahari desert 
of South Africa. 

The Great Kamerun 

The high volcanic peaks of equatorial Africa show, as might 
be expected, great changes in vegetation as one ascends. The 
great peak of Kamerun (13,370 ft.) has been carefully studied, 
and will serve as an example. 1 

At the base of the mountain, where the land has not been 
cleared, is a lofty rain-forest of the most pronounced type. Where 
the cultivated land has been abandoned, a second growth forest 
of a very different character soon occupies the clearings. This 
second growth forest contains many species which are unable 
to grow in the dense shade of the primitive rain-forest. Areas 
of meadowland and savanna also develop in the cleared spots, 
and in more open places are many attractive herbaceous plants, 
some having handsome Mowers, like Crinum, with big lily- 
like blossoms, or balsams (Impatiens) with attractive flowers 
of various colors. Ferns and some of the numerous gingers, 
are noticeable for their fine foliage, and some of the latter, also, 
have showy flowers. 

A very characteristic grass of this region is the elephant-grass 
{Pennisetum purpureum) which is ordinarily some ten feet in 
height, but may exceed this. This very valuable forage grass 
often covers extensive areas, and only permits a scattered growth 

1 Engler, loc. cit., p. 758. 




4> 




Plate XIII.— Welwitschia mirabilis. The upper figure showa the character ol 
the habitat; the lower a nearer view of the Btaminate plant. About 40 km. 
east of Swakopmund, West Africa. Photo., Dr. W. A. Cannon. 



167 



108 OUTLINE OF PLANT (UROGRAPHY 

of trees, among which arc the oil-palm, Kigelia, and the showy 
Spathodea. 

Above the lower forest zone, is a belt of second growth forest, 
with many oil- and wine-palms, and at a still higher elevation 
i< ;i mixed forest, of deciduous and evergreen species. Of the 
latter, figs are perhaps the most characteristic, and of the decid- 
uous trees, Erythrina excelsa is the most notable. Erythrina 
is a genus of leguminous trees with representatives in nearly all 
tropical regions. Most of them have extremely showy scarlet 
flowers, which often appear while the tree is bare of leaves. E. 
>.irelsa, as its name indicates, is a very tall tree, and blooms in 
December. It is a common tree and overtops all its neighbors. 

Among the many shrubs and smaller trees is a composite, 
Vernmia amygdalina, a near relative of the iron-weed of the 
eastern United States, but becoming a small tree. Among the 
many climbers, species of Clematis, morning glories (Ipomoea) 
vines (Cissus) related to the grape, and some others, are not 
entirely unfamiliar. 

The high forest extends in places to an elevation of about 
3,000 feet, but for the most part the forest at this elevation is 
composed of lower trees in great variety, and contains also many 
species of shrubs, climbers, and herbaceous plants. In the gorges 
especially, ferns become an important element in the vegeta- 
tion, among them a tree fern (Alsophila Kamarunensis) , and 
Marattia fraxinea, a fern with very big fronds. There is a pro- 
fusion of terrestrial herbaceous plants, orchids, Begonias, Coleus, 
balsams, and a graceful club-moss (Selaginelia nitens). Liver- 
worts and mosses play a more important role than at lower 
elevations, the trunks of trees being sometimes quite overgrown 
with them, as well as with ferns, and several species of epiphytic 
orchids, e. g., Angraecum, Saccolobium, are abundant. 

As at lower elevations, the clearings may support a heavy 
growth of elephant-grass, and there are many striking herbaceous 
plants in the more open parts of the forest. Among these may 
be mentioned Begonias, Clerodendron, several orchids, Coleus, 
and the foxglove-like flowers of Streptocarpus elongatus. 

Above 1,500 metres, wild coffee trees (Coffea brevipes) are 
found, and the vegetation begins to show an infusion of northern 
genera, Viola, Thalictrum, and others. 



THE PALAEOTROPICS 169 

The high forest stops at about 6,000 feet, a remarkably low 
point when compared with high mountains in much colder 
regions, as in the Rocky Mountains and Siena Nevada in Amer- 
ica, or the Himalayas. 

Above the forest zone, the mountain is covered with a grass- 
formation, interspersed up to 2,500 metres, with patches of 
stunted trees, which are covered with a heavy growth of 
epiphytes. 

The summit of the mountain has a flora which includes many 
familiar types of temperate climes, such as St. John's wort (Hy- 
pericum), buttercups, foreget-me-not, hound's tongue (Cynoglos- 
sum), milfoil (Achillaea), Stachys, Veronica, Galium, plantain, etc 1 

East Central Africa 

The region near the headwaters of the Blue and White Nile 
is an elevated rugged plateau of steppe character. It is largely 
open grass-land but there are also savannas and dry forest in 
places. The baobab and several species of Acacia are wide-spread 
in this region, and two characteristic palms, the Indian fan- 
palm (Borassus flabelliformis) and the dom-palm (Hyphaene 
Thebaica), are common, especially in the narrow forest areas 
along the rivers. 

This plateau region is enclosed by mountains which conned 
with the highlands of Abyssinia, and are the source of most of 
the water that feeds the Nile. 

The White Nile, especially, and its tributaries are in many 
places bordered by extensive swamps, formed by the flood water-. 
These marshes contain many characteristic aquatics, among 
which the famous papyrus is especially conspicuous. Between 
the clumps of papyrus, reeds, rushes, and other tall marsh plant-. 
are solid patches of "sudd," dense turfy masses of shorter grasses 
and other plants, which completely hide the surface of the water, 
giving the appearance of solid ground. Detached masses of 
sudd, floating in the open water, are often a serious hindrai: 
to navigation. 

Along the banks of the rivers, is a belt of forest, in which 
groves of palms are the most conspicuous feature, bu1 back 

1 For details of the flora of the Great Kamerun, sec Engler, loc. n't. 



171) OUTLINE OF PLANT GEOGRAPHY 

of this the land is either a grassy savanna with scattered trees, 
or a steppe covered with dry thorny, and in winter, leafless scrub; 
or sometimes, low open forest. 

Rising to the east and north are the highlands of Abyssinia, 
1,800-2,500 metres in height, and consequently temperate in 
climate. The lower portions of the western slopes, rising from 
the Nile steppe, have dry open woods with tall grasses between 
the trees, one of the commonest trees being the tamarind (Tama- 
rind us Indicus), which in general appearance is not unlike the 
American honey-locust (Gleditschia). Acacias of several species, 
figs, including the sycamore fig (Ficus Sycamora) and a variety 
of other trees and shrubs occur. Most of these shed their leaves 
in the dry season, and often flower before the new foliage appears, 
very much as do so many trees of northern climates. 

In the highlands there is no marked dry season, and the dif- 
ferences in the vegetation are due largely to soil and exposure. 
Where volcanic soils occur, there is a luxuriant evergreen forest 
in which species of Ficus are conspicuous, and in general the trees 
and shrubs are related to those of the drier lowlands. A date- 
palm (Phoenix reclinata) is common, and among the character- 
istic genera, are the following: Rhus, Pittosporum, Catha, Spar- 
mannia, Dombeya, Croton, Acacia. 

The more luxuriant vegetation of these moister uplands is also 
indicated by the increasing number of climbing plants, e. g., Aspar- 
agus, Dioscorea, Clematis, Rubus, Phaseolus, Convolvulus, etc. 

As in other tropical high mountains, there is a large floral 
element related to that of the temperate zone. In the Abyssinian 
highlands one meets with many species of such familiar genera 
as Gladiolus, Geranium, Pelargonium, Polygala, Hypericum, 
Primula, Campanula, Dianthus, Lobelia, and many others, 
especially members of the families Labiatae, Scrophulariaceae 
and Solanaceae. 

Some of these are closely related to, or even identical with 
European species, but many are unmistakably allied to species 
of the Cape region of Africa. In the latter category are many 
beautiful Iridaceae, e. g., Gladiolus, Moraea, Acidanthera; also 
many ground orchids (Habenaria, Plantanthera, Satyrium, Disa); 
Haemanthus, Crinum, Aloe, Mesembryanthemum, Protea, Ger- 
bera, etc., are also characteristic. 



THE PALAEOTROPICS 171 

The Abyssinian highlands have but two gymnospermous u> 
a juniper (Juniperus procera), which is abundant in Borne localitii 
and becomes a large tree, furnishing valuable timber; the second, 
Podocarpus gracMor, a member of the Yew family, represents 
genus characteristic of South Africa and others regions of the 
southern hemisphere. 1 

Eastward is the abrupt descent to the shores of the Red Sea. 
At the higher elevations, the temperate, well watered regions have 
an abundant vegetation; but as the descent is made to the in- 
tensety hot arid Red Sea shores, the plants assume more and more 
the xerophytic character common to so much of the tropical 
African flora. Cactus-like Euphorbias, Aloes, thorny Acacias, ju- 
jube (Zizyphus), together with various bunch-grasses and thorny 
shrubs, are the principal features. 

In places along the coast are mangrove swamps and saline 
flats, where salt-bushes and other salt-resistant plants grow, 
while on the coral rock are succulents of various kinds and the 
whole vegetation proclaims the intense heat and aridity of this 
inhospitable region. 

Southward from the equator to the Tropic of Capricorn, except 
for the Congo basin, the general type of country is very uniform, 
a plateau with moderate or scanty rainfall, and much barren 
soil. 

The predominant type of vegetation is the savanna, the amount 
of tree growth depending much on soil and moisture. This region 
is subject to a more or less pronounced dry season, during which 
many trees and shrubs are either quite leafless or with a few dry 
leaves clinging to the bare branches. Such a savanna country in 
the dry season presents quite as dreary a picture as the bare winter 
forests of northern climes. 

This savanna, " bosch-veldt " in the vernacular, may be seen 
well developed in the vicinity of the Victoria Falls of the Zamfo 

In 1905, the writer visited South Africa with the British Associa- 
tion for the Advancement of Science, and in September made the 
trip from Bulawayo, in Rhodesia, to the Falls. 

Bulawayo lies in the Matabele plateau between 4,000 and 5,000 
feet elevation, and the climate is much liko that of northern 
Mexico. About Bulawayo Moxican plants aiv said to l>r very much 

1 For details of the Abyssinian Flora, see Eimlrr, loc. cit.. pp. B4-127. 



172 OUTLINE OF PLANT GEOGRAPHY 

at home, and the writer noted a common Mexican bush-poppy 
(Hunneinannia) growing with remarkable luxuriance. 

In September the end of the dry season was approaching, and a 
number of showy trees and shrubs were coming into flower. 
Especially notable were the pendent racemes of yellow flowers of 
Cassia fistula, the "golden shower," of Honolulu, and the rosy 
flowers of the related Bauhinia sp. and scarlet flowered Erythrina. 

North of Bulawayo, where one takes the train for the Victoria 
Palls, lies the rugged range of granite hills, the Matoppos, where 
rests the body of Cecil Rhodes. From these barren granite rocks 
one looks over a vast expanse of "bosch- veldt," the trees growing 
fairly close together in some parts, elsewhere more scattered. 
Between are bunch-grasses, especially species of Andropogon, and 
Aristida stipoides, the latter a very tall and striking species. 

Although the climate is rather w T arm temperate than tropical, 
nevertheless many species are of equatorial origin, and are wide- 
spread over the great central African plateau. 

Among the largest trees were several species of Ficus, among 
them a variety of the sycamore fig, sometimes 25 to 30 feet high. 
I )t her t rees or large shrubs are species of Dombeya (Sterculiaceae) 
with white or pink flowers which are occasionally cultivated in Cali- 
fornia; Terminalia, Erythrina, Pterocarpus, Combretum, Cassia, 
Strychnos, and others. Leguminosae are particularly abundant. 
On some of the trees were growing parasites of the mistletoe 
family, Loranthus and Viscum, and an epiphytic orchid (Ansellia 
African a). 

Shrubby plants in great variety grow between the trees, some 
belonging to familiar types like sumacs and mallows; other 
characteristic genera are Colpoon (Santalaceae), Turraea (Mel- 
iaceae), Clerodendron (Verbenaceae), Euclea (Ebenaceae), Coffea 
Engleri (Rubiaceae). 

Among the rocks of the Matoppos, stunted trees and shrubs 
find a foot-hold. One of these, the " Natal plum " (Carissa edulis), 
is sometimes cultivated in Florida and Southern California. 

These rocky situations offer a congenial habitat for numerous 
succulents: Euphorbias, Aloes and a curious leafless plant (Sar- 
costemma) of the milkweed family. Several xerophytic ferns, 
(Cheilanthes, Pellaea), and a club-moss (Selagenella Dregei), grow 
in the rock crevices. 



THE PALAEOTROPICS 



173 



On the open veldt leguminous trees predominate. Acaci. 
abundant in all the drier parts of Africa, are represented by many 
species, usually small thorny trees with umbrella crowns. One 
of the commonest is A. giraffae, "Kameel-dorn," in the vernacular, 
the favorite food of the giraffe. A. horrida as its name implies, is 
a particularly thorny species. Peltophorum Africanvm, Copaifera 
sp., several species of Rhus, Combretum, Terminalia sericea, 
Strychnos, Dombeya, Burkea, Albizzia, Bauhinia, are all char- 
acteristic of the open veldt. 




Fig. 52. — Savanna vegetation, Victoria Falls, Rhodesia. 



As one travels northward from Bulawayo, the land descends to 
the Zambesi, the Victoria Falls being less than 1,000 metres above 
sea-level. The lower elevation, as well as lower latitude, makes the 
flora of the region more tropical in aspect than that of the higher 
plateau to the south. 

The vegetation is more luxuriant and the variety of trees and 
shrubs greater. Near the Falls the baobab is seen, and the tn 
in general are taller, and may form open forests of considerable 
extent. In September, these trees were mostly leafless, and the 
country covered with dry grass and leafless trees, presented any- 
thing but a picture of tropical luxuriance. The exception to this 



174 OUTLINE OF PLANT GEOGRAPHY 

impression was the occasional presence of a Cassia or Bauhinia, 
covered with golden or rosy flowers. 

A very common low shrub of the more open country is Protea 
m t( ; f< /". a member of the Proteaceae, a family particularly abun- 
dant in the Cape region, but poorly represented in tropical Africa. 

While the country as a whole between Bulawayo and the Zam- 
besi was very dry and dead-looking, where moisture was present, 
as along the banks of the infrequent streams, groves of palms 
(Hyphen m sp-)> 8 ave H 11 ^ a tropical look to the landscape. 

In the dry forest, trees 40-50 feet high are found, mostly Le- 
guminosae, with spreading crowns. The commonest of these are 
Baikiaea plurijuga and Copaifera coleosperma. The latter has 
bifid leaves like those of Bauhinia. Between the trees is a heavy 
growth of the tall grass, Aristida stipoides. Much of the country 
is more of the nature of a steppe, in which the baobab is a conspicu- 
ous feature, and the candelabra-Euphorbias, and Aloes, recall the 
Cacti and Agaves of Arizona and Mexico. 

A great contrast to the prevailing xerophytic vegetation of 
this region is seen in those places near the river which get a suffi- 
ciency of moisture. 

Thus on Livingstone Island, at the brink of the Falls, there is 
a vegetation of quite tropical luxuriance: palms, figs, orchids, and 
in the river, clumps of papyrus and other aquatics, offered a strong 
contrast to the parched dead landscape of the surrounding country. 
Such delicate moisture-loving plants as bladder-weed (Utricularia) 
and a pretty Lobelia, as well as other delicate herbs were common, 
and on rocks in the river, were specimens of a curious aquatic, 
Podostcmon. 

In a narrow ravine near the Falls, known as "Palmkloof " were 
many uraceful date-palms (Phoenix reclinata), evergreen figs, 
and other large trees, with numerous climbing plants and ferns, 
all testifying to the presence of ample moisture. 

Still more striking is the so-called rain-forest at the edge of the 
great gorge directly opposite the cataract, and constantly drenched 
with clouds of spray sent up from the narrow gorge into which the 
river plunges. The margin of the gorge, within reach of the shower 
of spray, is clothed with a dense growth of trees, with ferns, or- 
chids and other characteristic rain-forest species beneath, recalling 
the meat equatorial rain-forests, although the number of species 



THE PALAEOTROIM* - 



IT:. 



is much restricted by the limited extent of this "rain-fori 

as well as by latitude and elevation, which result in a much Lower 
average temperature than in the equatorial coastal belt. 

The most important trees of the Zambesi rain-forest are two 
species of Syzygium, a handsome evergreen tree of the myrtle 
family, which has few African representatives. These were low 
spreading trees, and with them were associated three species of 
Ficus, which were much taller, 50-60 feet, and over these w< r«- 
growing several stout woody climbers, with cable-like stems. 
The ground was carpeted with maidenhair, and other ferns, and 




Fig. 53.— " Rain-forest," Victoria Falls of the Zambesi, Rhodesia, 

among them were growing several orchids, as well as various other 
herbaceous plants. 

This bit of rain-forest is especially interesting as it was originally 
described by Livingstone when he discovered the great Victoria 
Falls. While it presents a decidedly tropical aspect, still one miss 
some of the plants which would be found at similar altitudes nearer 
the equator. Thus there are no tree-ferns, or the conspicuous 
wild gingers, bananas, arums and rattans which one associates with 
the upland rain-forest of the equatorial regions. This, however. 
is probably a matter of. isolation as much as temperature, since 
many of these tropical growths would probably flourish if trims- 
ported to the Zambesi rain-forest. 



176 OUTLINE OF PLANT GEOGRAPHY 

The Asiatic Tropics 

Unlike Africa, much the greater part of Asia is extratropical; 
bul the southeastern part of the continent, Indo-China and Malaya, 
shows a far more extensive and luxuriant tropical vegetation than 
any part of Africa except the relatively small equatorial region of 
the West Coast. The latter region, moreover, is much poorer in 
species than the Indo-Malayan flora, whose only rival is equatorial 
America. 

In western Asia, southern Arabia is the only region lying 
within the tropics, and this, in climate and vegetation is closely 
related to the regions on the African side of the Red Sea. Much of 
tropical India is also arid or semi-arid, and it is only in limited 
areas, like parts of the west coast, and the regions about the Bay 
of Bengal, that the vegetation exhibits the luxuriant development 
of the wet tropics, although owing to the mild climate of the south- 
ern slopes of the Himalaya, the vegetation is largely composed 
of tropical species which extend far into the temperate zone where 
there is a mixture of tropical and boreal types. 

The tropical Asiatic forest attains its highest development in 
the Malayan region, where equatorial conditions of heat and 
moisture combine to produce a maximum growth of the rank, 
exuberant, rain-forest vegetation. 

In the Malay Peninsula and the great islands of the Malay 
archipelago, Borneo, Sumatra, Java, New Guinea, and the southern 
Philippines, most of the lowland country has a hot-house climate 
with almost constant temperatures, and very heavy and uniform 
rainfall. When, in addition, rich volcanic or alluvial soils prevail, 
as in western Java and parts of Sumatra, the luxuriance and 
variety of the vegetation is unsurpassed in any part of the world. 

Arabia 

Arabia, north of the Tropic of Cancer, is in topography and 
climate like the deserts of North Africa, and the vegetation is 
much the same. The portion which lies within the tropics show 7 s 
much variety of elevation, and a corresponding range in precipi- 
tation and the resultant vegetation. 

From the almost rainless, intensely hot coastal belt along the 
Red Sea and Indian Ocean, the southwest point of Arabia rises 



THE PALAEOTROPICS 177 

very much like the corresponding shores of Africa on the w< 
side of the Red Sea, to an elevation of about 9,000 feel . 

As in Abyssinia, the higher mountains intercept the moisture- 
laden winds from the Indian Ocean, and the upper and intermediate 

elevations receive a fairly abundant rainfall, so that a luxuriant 
vegetation of sub-tropical and warm temperate type flourish* 
Very little moisture passes inland and the elevated plateau soon 
merges into the desert which covers much the greater pari of 
Arabia. The rainfall at the higher elevations is supplemented by 
frequent clouds and mists, and heavy dews play their part in 
conserving moisture. Conditions are especially favorable in the 
deep valleys and gorges eroded by the mountain streams. 

The vegetation of the mountains much resembles that of the 
Abyssinian highlands, but there is also a large endemic element 
more nearly allied to true Asiastic species, and related to the desert 
vegetation to the east. 

Of the indigenous plants, the original coffee (Coffea arabica), 
is the most notable. The Arabian town of Mocha is inseparably 
associated with this famous product of Arabia. As we have seen, 
other species of coffee occur in various parts of Africa, and one of 
them, the Liberian coffee, is extensively cultivated in regions 
where the Arabian coffee does not thrive. 

With the sub-tropical vegetation related to the Abyssinian flora, 
there are a good many Mediterranean species, so that the flora 
as a whole is an extensive one. This portion of Arabia was formerly 
much more densely populated than at present, and the centre of 
an important trade in gums, balsams, spices, etc., which abound in 
the hot semi-arid regions of medium elevation. 

"Araby the blest," " Arabia felix" of the ancients has sadly 
declined from those days when it was the source of the prized 
balsams and spices. The Arabian balsam was the product of 
trees of two genera Boswellea and Balsamodendron. Species 
of Acacia, as in Africa, are common, and from some of them the 
gum-arabic of commerce is derived. 

India 

Only about half of the total area of India lies actually within 
the tropics, and in the northwestern part, and much of t he Himala- 
yan districts, sub-tropical rather than tropical conditions prevail. 



178 OUTLINE OF PLANT GEOGRAPHY 

[mmediately south of the great barrier of the Himalaj^a lies 
the extensive alluvial plain extending from the Arabian Sea to the 
Hay of Bengal and comprising much of the land watered by the 
Indus and < ranges. 

The great plain of the Indus is extremely arid, sometimes 
absolutely rainless for a year or more. It is partly alluvial, partly 
occupied by saline swamps, but a large part is a sandy or rocky 
desert. Eastward the precipitation increases rapidly, and the 
central, and especially the eastern portions of the Gangetic plain, 
have a heavy rainfall. This is greatest about the head of the Bay 
of Bengal, and the Ganges delta, where annual precipitation 
exceeding 100 inches is not unusual. 

The central and eastern plains, which get the regular monsoon 
rains, are extremely productive, and the most densely populated 
portion of India. 

Most of the tropical part of India is comprised in the great 
central plateau, enclosed by low ranges of mountains near the 
coast, and a range to the north separating it from the Gangetic 
plain. The two coastal ranges, the Western and Eastern Ghats, 
converge southward, and are partially connected by transverse 
hills. The great enclosed central plain is the Deccan, a plateau of 
about 3,000 feet elevation. The northern portion of the Deccan 
is semi-arid, as the moisture of the southwest monsoon is mostly 
intercepted by the Western Ghats. To the south, conditions are 
better, but nowhere in the interior of India are conditions such that 
a tropical rain-forest can develop. 

The western coast (Malabar), receives the full benefit of the 
southwest monsoon, and has an abundant rainfall, resulting in 
evergreen forests of true tropical luxuriance. 

The conditions northeast of the Bay of Bengal are such that in 
\-;mi and the Kasi hills, there is an excessively heavy rainfall. 
One station, Cheripunji, has an annual precipitation of nearly 
500 inches, exceeding this in some years, giving it the reputation 
of the rainiest spot in the world. This region, however, lies out- 
side the tropics, and the vegetation, although extremely luxuriant, 
is to a great extent sub-tropical, rather than tropical. Separating 
the Indus and Ganges plain from the plateau of the Deccan is a 

ries of hills or low mountains of which the highest, Mt. Abu, 
rises above the Punjab plain to an altitude of 5.650 feet. Famous 



THE PALAEOTROPK - 179 

for the beautiful Jain temple-. Mt. Abu is often visited by tourif 
in northern India. 

The Western Ghats rise from the western coast in a series of 
terraces. The highest point is 4,700 feet above the sea. From tin 1 
eastern edge of the Ghats, the plateau slopes gradually to the I 
elevated Eastern Ghats, the two border ranges uniting a1 the south 
in the Nilgiri Hills, with an extreme elevation of 8,700 feet. The 
enclosed Deccan plateau, with an elevation of from 1,000 to 3,000 
feet, is occupied by the Central Provinces. 

The southern point of the Peninsula has mountains along the 
coast, continuing the Western Ghats; but the eastern side is 
nearly level with only isolated ranges of low hill-. 

Separated from the extreme southern point of the Indian 
Peninsula, by only about 50 miles, is the Island of Ceylon. 

The Indus Plaix 

The northwestern plains of India traversed by the Indus, are a 
continuation of the great desert stretching from Egypt through 
Arabia and Mesopotamia. Excessively hot in summer, with 
relatively cold winter, the whole region is too arid for agriculture, 
except where irrigation is available. Some parts of this region are 
practically rainless. 

The scanty vegetation is very uniform throughout, and in 
northwest India the vegetation is much the same as in the desert 
regions to the west. Thorny Acacias (A. Arabica), a poplar 
(Populus Euphratica) and wild figs grow along the streams, 
tamarisk and jujube (Zizyphus sp.), sl leafless caper (Capparis 
aphylla), and various shrubby Leguminosae are the most important 
elements of the flora. 

The northwest provinces get very little rain from the south weM 
monsoon, which is deflected to the east by the mountain- t<» the 
south. This whole region is dependent upon the Indus, which 
furnishes water for irrigation, but apparently the flow of the river 
has diminished since ancient times. 

The original flora of the great alluvial plains of the Punjab and 
Bengal has long since disappeared before the intense cultivation 
of the land for ages by the dense population, and the whole region 
is practically destitute of any indigenous forest formation-. < hily 




Plate XIV.— Vegetation near Mt. Abu, northwest India. At the right, on the 

rocks, a bushy Euphorbia. 



180 



THE PALAEOTROPICS 181 

in the most barren regions, impossible of cultivation, can one find 
any wild vegetation, and the desperate poverty of much of this 
over-populated region leaves scarcely a trace of any tree, shrub, or 
weed that can be used for fuel. 

Journeying in Rajputana, from Mt. Abu to Jaipur, the principal 
city of the Province, one passes through a less densely populated 
country, an open dry region, with rugged hills and scattered 
stunted trees. Acacias, the showy "Dhak" {Butea frondosa,) 
with brilliant scarlet flowers, "Neem" (Azaderachta indica) with 
ash-like leaves, and wild date-palms {Phoenix sylvestris). In the 
rocky places one sees cactus-like Euphorbias, like those of Africa, 
and other xerophytes. 

The Gangetic Plain". Bengal 

The eastern portion of the great plain of the Ganges, is a region 
of exuberant fertility, and very densely populated. Rice is the 
staple food-crop, but most tropical fruits, bananas, mangoes, 
papaya, etc, thrive. Indigo, cotton and jute are important crops 
and the opium poppy is grown on a large scale. Bamboos, palms 
of several species, and many ornamental trees and shrubs are 
extensively planted. 

As one approaches Calcutta from the sea, the scenery along 
the river banks is very attractive, the villages and plantations, 
with their luxuriant vegetation, testifying to the fertility of the 
country. The famous botanical gardens, on the bank of the river 
a few miles below the city, will at once attract the attention of the 
botanist. These gardens are interesting not only for their rich col- 
lections of plants, native and exotic, but for a hunched years <>r 
more they have been the centre of botanical research for British 
India, and are intimately associated with the labors of many 
distinguished British botanists. 

A very large collection of trees is a feature of the garden and 
includes magnificent avenues of mahogany, "almond " (Terminalia 
catappa), royal palms, and other striking species of which the palm 
collections comprise many both native and exotic. 

The pride of these gardens is an immense banyan (Ficu 
galensis), said to be about 135 years old in 1900, five years before 
the writer saw it. It had a main trunk 51 feet in circumferei. 



lv_> 



OUTLINE OF PLANT GEOGRAPHY 



and over 460 smaller root-trunks, while the crown was 938 feet in 
circumference. 

The vegetation about Calcutta is luxuriant, including several 
species of palms, screw-pines, bamboos, bananas, and many other 
characteristic tropical growths. The graceful betel-nut (Areca 
Catechu) and the coco-palm are extensively planted, as well as 
the native toddy-palm (Borassus flabelliformis) , with great fan- 
leaves. The wild date-palm {Phoenix sylvestris) is very common, 
as it is elsewhere in India. 

Besides the banyan, another species of Ficus is common in 




Fig. 54. — Banyan (Ficus Bengalensis) , Botanical Gardens, Calcutta. 



India, the "Pipul" (F. religiosa), with heart-shaped leaves sug- 
gesting a cotton-wood poplar. 

Approaching Calcutta from the sea one sails up the Hugli River 
through the swamp region known as the "sunderbans." 

The mangrove swamps of the Indo-Malayan regions are much 
like those of East Africa, but developed on a much more extensive 
scale, and with a greater number of species. As in Africa the out- 
side is composed of Rhizophora mucronata, the predominant species 
throughout the Malayan and Australasian regions. Other man- 
groves occupy the inner portion of the swamp, e. g., Brughiera 
spp., Avicennia officinalis, and a number of other characteristic 
genera, e. g., Sonneratia, Acanthus, Carapa, and the Nipa-palm. 1 

1 Schimper, A. F. W., Plant-geography, p. 395. 



THE PA LIPOTROPICS 183 

At high tide the mangroves appear to rest on the Burface of the 

water, but with the ebbing tide the shiny black mud banks are 
exposed, showing the fantastic tangle of stilt-root-. These aerial 
roots are important aerating organs for the roots buried in the 
mud; the white mangrove (Avicennia), sends up myriads of Blender 
aerial roots or "pneumatophores" for the same purpose. 

The seaward extension of the mangrove formation may be 
rapid. The seed germinates while still attached to the parenl 
tree, and the seedling develops into an elongated, rod-like body, 
ending in a stout root. The young plant, detached from the branch, 
falls like a plummet, the root penetrating deep into the mud, thus 
firmly anchoring the seedling mangrove, which quickly forma 
a bush of considerable size. 

Back of the swamp, as noted for West Africa, there is built 
up a strip of drier soil which gradually adds to the mainland. 

The great delta area of the Ganges back of the mangroves is 
largely a region of fresh water marshes and wet forest, support- 
ing a great variety of hygrophilous plants, among them many 

palms. 

The low vegetation, with brackish swamps, chiefly composed 
of dwarf palms and mangroves, does not give an impression of 
tropical luxuriance, and it is not until the sandy spits and marshy 
jungles of the delta are passed, that the full luxuriance of the 
tropical vegetation is seen. In the delta of the Ganges, as in 
other tidal swamps of the East, the Nipa-palm is a conspicuous 

feature. 1 

Directly north of Calcutta is the well-known mountain station 
Darjiling, commanding probably the finest mountain-panorama 
in the world, as it comprises a perfect view of the main range of 
the Himalaya, with the giant Kinchinjunga in the centre. 

The journey from Calcutta to Darjiling is a most interesting 
one to the botanist. A line running from Calcutta to Darjiling 
has been proposed as a division between two quite dissimilar 
floras, that to the east being predominantly Malayan, while west- 
ward there is a marked infusion of African types. 

Proceeding northward from Calcutta the rank luxuriance of 
the delta country is succeeded by the drier portion of the ( rangetic 
plain and still further northward the "Terai' is reached, the 

1 Hooker, J. D., Himalayan Journals, pp. 1-2, I s 



1M OUTLINE OF PLANT GEOGRAPHY 

jungle belt Bkirting the foot of the great range of the Himalaya. 
This jungle is composed for the most part of stunted scrubby trees 
and shrubs, with coarse tall grass between. The commonest trees 
art 1 species of Acacia, Dalbergia, Sterculia, and several others. 
This region is notoriously malarial, and the haunt of tigers and 
other big game. 

The change in the vegetation as one ascends from Siliguri, 
at the base of the mountains to Darjiling, about 7,000 feet eleva- 
tion, is very marked, and as the tiny train makes very slow prog- 
resa along the steep and crooked track, one has ample time to 
study the character of the forest along the railway. 

Up to an altitude of about 3,000 feet, the forest has a decidedly 
tropical aspect, although it lies beyond the northern tropic; but 
the southern slopes of the great mountains have abundant mois- 
ture, arid an equable climate. 

A lofty forest replaces the scrub of the Terai and includes some 
very large and valuable trees. Of these the most important is 
the "Sal" (Shorea robusta), a gregarious species, and a very im- 
portant timber-tree belonging to the peculiarly Indo-Malayan 
family. Dipterocarpaceae. Other notable trees are the "cedar" 
(Cedrda Toona), a wide-spread species reaching to Northern 
Australia, and several species of Terminalia which like the cedar, 
shed their leaves in the dry season, as many other Indian trees 
do; Gordonia WaUichii, belonging to the Camellia family, and 
a genus also represented in the southern United States is a common 
tree of the sub-Himalayan forest, and several species of Ficus are 
also characteristic of this tropical zone. 

The tropical character of this forest is most pronounced at the 
lower levels, especially in the deep, very wet lower valleys of the 
streams descending from the mountains. Palms, bananas, bam- 
boos, screw-pines, huge Aroids, and other characteristic tropical 
types abound. Few of these extend above 3,000 feet, where there 
begins an intermingling of the temperate types characteristic 
of the upper Himalayan forest region. Thus a pine (Pinus longi- 
folia) occurs as low as 1,500 feet, although most of the vegetation 
at this elevation is tropical. 

The abundant moisture, especially in the sheltered valleys 
and gorges, favors a luxuriant growth of climbing plants and 
epiphytes. 



THE PALAEOTROPICS 185 

As in most tropical forests, the Leguminosae are among the 
commonest of the lianas. Among these are species of Mucuna, 
Pueraria, Bauhinia, Entada, while the Vine family, is represented 

by a number of species of Vitis; Peppers, Ipomoeas, Bignonii 

and big-leaved Araceae form great cables looped from tree t<> ti 
or clamber up the trunks and branches of the lower trees and 
shrubs. Rattan-palms of several species are characteristic, and 
some of these reach into the temperate zone up to 7,000 feet. 

The screw-pines (Pandanus), with leaves 8 to 10 feet long, and 
bamboos of several sorts, are striking features of the vegetation. 
The bamboos are especially abundant in the Himalayan forest, 
and many species extend into the temperate zone. Some of these 
are gigantic, sometimes a hundred feet high. 

Ferns are abundant, and include some fine tree-ferns (Also- 
phila sp.) as well as many epiphytes, and epiphytic orchids are 
common, some of them of great beauty. 

Above 3,000 feet the tropical forest shows an increasing number 
of temperate species which become predominant above 4,000 
feet x and from this elevation to Darjiling (7,000 ft.), the flora 
has much in common with the temperate floras of Eurasia and 
North America, especially the Atlantic States. 

Assam and Upper Burma 

Northeastward from Bengal, and continuous with the tropical 
Himalayan forest belt is Assam, which includes the valley and 
delta of the Brahmaputra, and a series of mountain ranges with 
their intervening valleys. It is a region of excessively heavy rain- 
fall, and the rain-forest of the valleys and lower hills is an east ward 
extension of the lower Himalayan forest zone, and reaches further 
eastward into Burma and Indo-China. 

This forest, however, while made up largely of Indo-Malayan 
tropical genera, also, especially at higher elevations, as in the 
Himalayas, has many species of northern rather than tropical 
affinities, such as oaks, chestnuts, camellias, and others. The 
whole of this region lies within the monsoon belt. i. c, it has a more 
or less pronounced dry season, and a considerable number of 
deciduous trees. 

1 Hooker, loc. cit., pp. 95-100. 



186 OUTLINE OF PLANT GEOGRAPHY 

The Western Ghats 

The Western Ghats descend by a series of terraces to the coast, 
and these slopes, and the coastal strip below, get the full benefit 
of the southwest monsoon, and the dry season is much less pro- 
nounced than in the interior of the country. The whole coast 
line, as far north as Bombay, is clothed with luxuriant evergreen 
forest, and presents a marked contrast to the barren shores of 
northwest India. 

These evergreen forests have much in common with the rain- 
forests of eastern Bengal and Assam, but many of the Malayan 
species are wanting and there is an admixture of African types. 
The tropical character of the vegetation becomes still more 
pronounced toward the south, where the flora is much like that 
of Ceylon. 

Descending on the east to the Deccan plateau, much drier 
conditions prevail. This is especially marked close to the eastern 
slope of the mountains, as the rains pass over the crest and fall 
some distance inland. 

Between Bombay and Poona, on the eastern side of the Western 
Ghats, the lowlands are very productive, rice and other tropical 
crops growing luxuriantly, and a profusion of palms of several 
species, evergreen figs, bamboos, and other luxuriant vegetation, 
forming a characteristic tropical landscape. 

Further south the interior country is much drier, and where the 
forest still remains, as in the gorges on the flanks of the mountains, 
the trees are mostly deciduous in the dry season. Some of these 
trees are of great value as timber, among them being the "sal," 
already referred to, and the very important teak (Tectona grandis). 
The open country is too dry for a true forest, but there are many 
species of shrubs and small trees, many of which are also common 
to the dry northwestern provinces. 

Passing from the rich evergreen forests of the seaward side of 
the Western Ghats, and descending to the dry plain of the Deccan, 
there is a transition first through a moist deciduous forest to a 
dry open forest which gradually passes into the thorny scrub of 
the Deccan. 

On the eastern shore of the Peninusla which gets rain from the 
northwest monsoon from the Bay of Bengal, there is nearly ever- 



THE PALAEOTROPICS is? 

green forest, but much less luxuriant than that of the west coa 
and denominated by Brandis l "semi-evergreen scrub." Among 
the constituents of this formation may be mentioned species of 
Flacourtia, Pterospermum, Erythroxylon, Carissa, Ehretia. 
Where moisture is more abundant, as in some of the hill-country. 
and parts of Madras, this formation becomes a true evergreen 
forest. 

The province of Madras, occupying the southeastern part 
of the Peninsula is open to the sea and much better watered than 
the Deccan. It is a fertile region, and travelling through in De- 
cember, the writer noted luxuriant crops of rice and cotton, the 
latter in full bloom. Tobacco and millet are both important crops. 

A very different flora is found in the Nilgiri Hills where the East- 
ern and Western Ghats join. In the higher elevations, which ex- 
ceed 7,000 feet, a temperate flora occurs much like that of the 
eastern Himalaya and the mountains of Assam and north Burma. 
Such common northern genera as Rubus, Viburnum, Rhamnus, 
Hypericum, etc., occur, many of them the same species as those 
of the mountains of northeast India. 

Ceylon 

Ceylon, an island of more than 25,000 square miles area, owing 
to its proximity to the equator has a uniformly hot climate, with- 
out the extremes that prevail in much of continental India. In 
the humid coastal areas, such as Colombo, the annual range is 
very small. 

The rainfall varies much in the different parts of the island, and 
is largely controlled by the trend of the principal mountain in 
which rises to over 8,000 feet in the southwest. This range is an 
effective barrier to the passage of the rain-clouds brought by the 
southwest monsoon in the late spring, and most of the moisture is 
precipitated on the seaward side of the mountains, while the north- 
eastern plains get very little rain at this time. In the autumn, the 
northwest monsoon brings much more general, but less heavy 

rainfall. 

The flora of Ceylon, in its main features, is much like thai of 

1 For details of the vegetation of the forest regions of India, Bee Bran. lis. P.. 
Indian Trees, London, 1906. 




Plate XV.— Screw-pine (Pandanus sp.), Botanical Garden, Peradeniya, Ceylon. 



188 



THE PALAEOTROPICS 189 

southern India, bat there is a pretty large proportion of peculiar 
species. 

Little forest remains in the lowlands, except in swamp}- regions 
unfit for cultivation, and such as remains is not particularly 
luxuriant. In the drier districts are many of the same species 
of trees and shrubs as in southern India, e. g., species of Acacia, 
Cassia, Eugenia, and others, but in the more humid districts, like 
those about Colombo, little is left of the original vegetation, 
and most of the available ground is occupied by various crops, — 
rice, sugar, coconuts, and the usual fruit trees: bread-fruit, 
bananas, papaya, mangoes, etc. Coconuts form one of the most 
important products of Ceylon, and are planted in enormous 
numbers, forming almost uninterrupted groves along the shore 
for many miles. 

Practically all the forest in the humid areas between 2,000 and 
4,000 feet elevation has been destroyed for the purpose of planting 
tea. The coffee plantations of an earlier period were destroyed 
by the ravages of a fungus, and were replaced by tea, which is now 
the principal product of the island, being cultivated up to 6,000 
feet elevation. Rubber is also cultivated to some extent but can 
hardly compete with the plantations of the Malay region. 

Neither in soil nor climate is Ceylon equal to the great Malayan 
islands, and as the general character of the lowland vegetation 
of Ceylon is similar to that of the Malayan region, but is less 
luxuriant and varied, it will not be considered further. 

Some efforts have been made at reafforestation in Ceylon, 
and teak has been planted with some success in the lowlands. 
The writer visited the Hanwella forest not far from Colombo, 
where there are teak plantations. The luxuriance of the vegeta- 
tion gave evidence of an abundant rainfall, although it was the 
dry season (Feb.). There were many ferns, including a beautiful 
climbing species (Lygodium sp.) as well as a good many epiphytic 
ones, among them the curious giant adder-tongue, Ophioglossum 
pendulum, whose forked strap-shaped fronds hung down for nearly 
two yards in length. A number of epiphytic orchids were also 
noted. Of the terrestrial ferns, the most interesting was Hd- 
minthostachys Zeylanica, a relative of Ophioglossum, and wide- 
spread through the eastern tropics. There were a number of 
showy flowers noted, one a beautiful blue gentian (Exacum sp.) 




Plate XVI. — Giant bamboo (Dcndrocalamus giganteus), Botanical Gardens, 

Peradeniya. 



190 



THE PALAEOTROPICS 191 

and the fine Ixora coccinea, a shrub with clusters of tubular 
scarlet flowers. 

At Peradeniya, about 1,700 feet elevation, is a fine botanical 
garden, with a large collection of tropical and sub-tropical plants, 
including the most notable native species. There are some re- 
markably fine clumps of the largest of all bamboos (Dendrocala- 
mus giganteus) more than a hundred feet high. Here may also 
be seen fine specimens of the native Talipot-palm (Corypha um- 
braculifera), whose immense fan leaves are over four yards across. 
At maturity an enormous terminal panicle of flowers is developed, 
after which the tree dies. In the early spring many of the showiest 
trees come into flower. One of these, Bombax Malabaricum, is 
a very large tree with big carmine-red, mallow-like flowers, espe- 
cially striking, as the tree is quite leafless when in bloom. The 
magnificent Amherstia nobilis, from Burma, was especially fine at 
Peradeniya, and the long pendent racemes of brilliant red flowers, 
looking like orchids, make it one of the finest of flowering trees. 
The principal mountain mass of Ceylon rises to a plateau, 
6,000-7,000 feet high, with some peaks a thousand feet higher. 
The climate of the plateau is temperate, and the vegetation is 
reminiscent of the Nilgiris of South India, or the temperate Hima- 
laya. As the plateau is too high, in most places, for tea culture, 
it is still largely in a state of nature, and shows little admixture 
of introduced species. 

This region is a combination of low evergreen forest and open 
grass-land, the latter known locally as "Patana." The line be- 
tween patana and forest, is a very sharp one. The evergreen forest 
is composed of a good many genera, e. g., Eugenia, Calophyllum, 
Luytsia, Symplocos and others. A feature of this region is a 
magnificent tree-rhododendron (R. arboreum), also found in the 
Himalaya. It is a spreading tree of considerable size, the flowers 
a brilliant blood-red, presenting a splendid sight- 
In the early spring, the young foliage of these evergreen forests 
shows a great variety of color, red, yellow, pink and purple, the 
effect being very beautiful. 

The herbaceous plants are largely familiar boreal types. Thus 
at Horton Plains, the following genera were noted: Viola, Hy- 
pericum, Gnaphalium, Lobelia, Ranunculus, Gentiana, Gaul- 
theria, Alchemilla, Fragaria, Plantago. Other less familiar were 




Plate XML— Talipot-palm (Corypha umbraculifera) ; at right, betel-palm (Areca 

Catechu). Botanical gardens, Peradeniya. 



192 



THE PALAEOTROPICS 



193 



the blue-flowered Exacum, Hedyotis, Strobilanthus and Ceropegia 

( Asclepiadaceae) . 

Orchids are quite common, a beautiful white epiphytic species 
{Coelogyne odoratissimum) being especially abundant. Other 
orchids noted were species of Dendrobium, Satyrium, Oberonia, 
Listera. 

Ferns are well represented, especially in the moist shady forest, 
but some species are characteristic of the open and drier plae. 3. 
On rocky banks, Gleichenia dichotoma (linearis), a cosmopolitan 




Fig. 55. — Botanical Garden, Hakgala, Ceylon. 

species, forms thickets, and associated with it is an equally wide- 
spread club-moss, Lycopodium cernuum. In the shady localitn ts 
one may find some of the filmy ferns (Hymenophyllaceae), but 
these are not particularly abundant. In sheltered gullies are fine 
tree-ferns, the most abundant one being Alsophila crinita. In 
the moist grassy meadows an adder-tongue fern, Ophioglossum 
reticulatum is not uncommon, and occasionally a related fern, 
Botrychium lanuginosum is met with. The boggy meadows also 
harbor sundews (Drosera spp.), and bladder-weed (UUricularia 
sp.), as well as several club-mosses, two of which, Lycopodium 
clavatum and L. Carolinianum are characteristic boreal species. 



L94 OUTLINE OF PLANT GEOGRAPHY 

In the shady woods, the trees me draped with the gray stream- 

3 of the lichen, Usnea, and here are also found a variety of 
epiphytic mosses and liverworts, which also are plentiful on the 

Kind and on rocks and fallen logs. 

In the cool moist climate of the Ceylon highland, most of the 
common garden flowers come to great perfection. In the attract- 
ive gardes at Hakgala, together with a great variety of orchids, 
peppers, tree-ferns, and other sub-tropical plants, there were 
beautiful begonias, geraniums, heliotrope, fuchsias, violets, roses, 
etc., .mowing with unusual luxuriance. 

Ixdo-China 

The Indo-Chinese peninsula, comprising Burma, French Indo- 
china and Siam, has a flora, w r hich includes elements belonging 
respectively to the Indian, Himalayan and Malayan regions. 

To the north, radiating from the great Himalayan system which 
forms the southeastern boundary of Tibet, extends a series of 
mountain ranges between which lie the valleys of the great rivers, 
Irrawaddy, Salween, and Mekong, which water the lowlands of 
Burma and Siam. 

In the northern mountain country the vegetation is a continua- 
tion of the temperate Himalayan flora, and includes many genera 
related to the floras of both Eurasia and North America. Pines, 
firs and other coniferous trees; oaks, maples, magnolias, rhodo- 
dendrons, and many others, both herbaceous and woody plants, 
are familiar to European and American botanists. There are, 
however, mingled with these boreal plants, many which are re- 
lated to the tropical Malayan flora, such as bamboos, palms, 
many orchids, figs and others. 

In the lower country in Assam, Burma and southern China, 
the vegetation is predominantly Malayan, and further south, 
most of the boreal genera disappear, and the vegetation is almost 
entirely composed of strictly tropical types. Only in the higher 
mountains do we again encounter the northern plants. 

There are three principal mountain systems extending south- 
ward from the Himalaya in the Indo-Chinese Peninsula. To 
the wesi is the Arakan system of Burma; in the centre the ranges, 
which extending southward, form the backbone of the Malay 
Peninsula; to the east the mountain system of Annam. 



THE PALAEOTROPICS 



195 



These north and south ranges exert a great influence upon the 
climate, as much of the moisture from the southwest monsoon 
over the Bay of Bengal is intercepted by the Arakan range, so 
that Burma has a much heavier rainfall than Siam. 

In Burma, however, there is by no means a uniform climate. 
The northern mountain region, next to Assam, has practically no 
diy season; but over most of the country, as in central India, the 




Fig. 56. — Great pagoda, Rangoon, Burma. The trees are toddy -palms 

(Borassus flabelliformis) . 

monsoons, especially the southwest monsoon, have a marked effect 
upon the climate. 

The coastal region of Burma, including the deltas of the Ir- 
rawaddy and Salween, and the coast south of Rangoon, have a very 
heavy rainfall, and correspondingly luxuriant vegetation. The 
delta-lands below Rangoon, when reclaimed are extremely fertile. 
This is a region of immense rice ("paddy") fields, rice being the 
great food crop of the country; but all the characteristic tropical 
products abound. Oranges, bananas, mangoes, bread-fruit, 
Jack-fruit, and others less familiar, are associated with bamboos, 
palms of many kinds, cinnamon, tamarinds and many other tr< 
shrubs and herbs. 



196 OUTLINE OF PLANT GEOGRAPHY 

A common and beautiful palm of this region, and indeed every- 
where throughout the Malayan tropics is Areca Catechu which 
produces the "bet el-nut," which mixed with lime and the leaf of 
the betel-pepper, furnishes the Malayan equivalent for chewing 
gum. The Areea-palm is one of the most beautiful of the palm 
tribe, its perfectly smooth, slender shaft bearing aloft a plume of 
graceful feathery leaves. 

Where the delta lands have not been cleared and drained, they 
comprise a labyrinth of swamps and low jungle like the sunder- 
buns of the Ganges delta, on the opposite side of the Bay of 
Bengal. 

As one travels northward, through the valley of the Irrawaddy, 
the country becomes much drier, and above Mandalay the coun- 
t ry is largely a dry savanna, open grass-land, and scattered deciduous 
trees, recalling the bush-veldt of South Africa. Where the forest 
is better developed, the trees are mainly deciduous, and in places, 
teak forests of considerable extent occur, and the timber is of 
great commercial importance. 

While the valleys show evidences of a marked dry season, the 
higher mountains have a heavier, and more uniform rainfall and 
especially in the gorges cut by the rivers, there is a typical rain- 
forest with a profusion of beautiful trees, shrubs and herbaceous 
plants. Upper Burma is especially rich in orchids, many of w r hich, 
like the exquisite blue Vanda coerulea are greatly prized in cultiva- 
tion. 

Siam and Annam, on account of the mountains lying between 
them and the Bay of Bengal, lose much of the benefit of the 
southwest monsoon rains, and on the whole are much drier 
than Burma, as the northeast moonsoon brings much less rain 
than the southwest. 

Much of the lower country is open savanna, and the forests, 
even in the hill-country are much less luxuriant than those of 
the coastal region and mountains of Burma. 

While the greater part of the Indo-Chinese peninsula has a 
pronounced monsoon climate, the long extension southward, 
the Malay Peninsula, reaches the equatorial zone, and the wet 
and dry seasons are much less marked. 

Somewhere in Indo-China, may have been the birthplace 
of the human race. The discovery of the famous Ape-man 



THE PALAEOTROPICS 197 

(Pithecanthropos) in Java points to this part of the world as 
the place where man first appeared. 

Long before western civilization began, India and China 
were highly civilized communities, and today contain a very 
large part of mankind. Southeastern Asia, with the adjacent 
islands, is one of the richest parts of the world, abounding in 
food-plants of many kinds, and man very early learned to cul- 
tivate and improve the most important of these. The great 
food staple of most of the Orient is rice, native to this region, 
and the many varieties of bananas and plantains are undoubtedly 
derived from some of the many wild species, and the same is 
true of sugar cane. 

Many important tropical fruits, mangoes, durian, mangosteen, 
and others are natives of the Indo-Malayan tropics, and to 
China we are probably indebted for the orange and other Citrus- 
fruits, as well as the peach and perhaps the apricot. 

This region, too, abounds in spices, pepper, cloves, nutmeg; 
and the palms, bamboos, rubber and gums yield various impor- 
tant commercial products. 

It is not remarkable, that in a region so richly dowered by 
nature, primitive man should have found a congenial habitation, 
increased and multiplied. 

The Islands of the Indian Ocean 

The islands in the Indian Ocean lying east of Africa, owing 
to their isolation, have developed very characteristic floras. 

Much the most important is Madagascar, next to Papua and 
Borneo the largest island in the world. Separated from the main- 
land by two hundred and sixty miles, its 228,000 square miles 
show a great variety of conditions, and the vegetation is equally 
varied and includes many extremely interesting endemic species. 

A mountain range occupies the centre of the island, averag- 
ing about 5,000 feet in height, with an extreme elevation of 8,675 
feet. This central region, which is largely made up of fertile 
plains and valleys, has a warm temperate climate; but the coastal 
zone has a pronounced tropical climate, very humid on the east, 
which receives the full benefit of the moisture-laden ocean winds, 
but much drier on the lee-side of the island. 



I'.is OUTLINE OF PLANT GEOGRAPHY 

Much of the land on the windward side is covered with heavy 
rain-forest, but on the west side the vegetation is very much 
like those parts of British South Africa which lie in the same 
latitude. There is a marked dry season and the vegetation is 
more or less decidedly xerophytic. Aloes, Euphorbias, Acacias, 
and other characteristic South African types abound, and in 
some places Cacti, introduced from America, have become nat- 
uralized. The extreme southwest of Madagascar is very dry, 
and may be called a desert. 

In the rain-forest and the moister portions of the mountains, 
ferns are very abundant, and orchids are also a marked feature 
of the vegetation. One of the most striking of the orchids 
is a species of Angraecum, sometimes seen in cultivation, which 
has a spur, or nectary, a foot long ! 

There are many striking species peculiar to Madagascar, 
some of which are not uncommon in cultivation. Of these may 
be mentioned the " Flamboyant" (Pointiana regia), perhaps 
the showiest tree in cultivation, with its masses of flaming scar- 
let flowers. The " traveller's tree" (Ravenala Madagascariensis) 
is sometimes grown in warmer countries, where its great fan of 
big banana-leaves at once attracts attention; and sometimes 
one sees in conservatories the curious lace-leaved water-plant, 
Ouvinandra fenestralis. 

Other characteristic plants are a peculiar screw-pine (Pandanus 
obeliscus), a handsome crape-myrtle (Lagerstroemia sp.), sl palm 
(Raphia ruffia), and several rubber-plants, species of Vahea. 

Some of the trees — e. g., Weinmannia, Elaeocarpus, Casuarina — 
are reminiscent of the Malayan- Australian region; but the bulk 
of the vegetation, especially in the drier parts, is unmistakably 
African. In the cooler mountain districts there are many species 
either identical or closely related to those of the highlands of 
Abyssinia and the Cape region. 1 

East of Madagascar are the Mascarene Islands, which like 
most tropical mountainous islands are notable for the great 
profusion of ferns. Orchids are also very abundant, and there are 
a number of interesting palms. Some of the latter are closely 
related to those of the African mainland — but others are more 
nearly allied to those of Indo-Malaya, or even of America. 2 

1 Drude loc. ciL, pp. 475-476. 2 Ibid., p. 476. 



THE PALAEOTROPICS 199 

The Seychelles 

The Seychelle archipelago, six hundred miles northeast of 
Madagascar, comprises forty-five islands lying between 3° 38' 
and 5° 45' south latitude. The flora is a very distinct one and 
includes six endemic genera and sixty endemic species. Five of 
the endemic genera are palms, and one, Northea Seychellana, a 
tree belonging to the Sapotaceae, was named in honor of Miss 
Marianne North, who visited the islands in 1883-1884 and who 
has given an interesting account of her visit, which was especially 
for the purpose of painting the extraordinary palm, Lodoicea 
SeycheUarum, which bears the huge double coconut, a well-known 
botanical curiosity. 1 

The forest is rich in palms, tree-ferns, and screw-pines; and there 
are a good many trees, one of which, Wormia ferruginea, an 
endemic species, is especially abundant in the higher mountain 
forests. Miss North found pitcher plants (Nepenthes) on the top 
of the higher mountains. A single species is also found in Mada- 
gascar, and these, as well as some other forms, show an affinity with 
the Malayan flora. The most striking flowers noted by Miss North 
were two fine orchids, Angraecum eburneum and Vanilla Phalaen- 
opsis. 

1 Marianne North, Recollections of a Happy Life, Vol. II., London, 1893. 




CHAPTER VII 

THE PALAEOTROPICS-Continued 

MALAYA AND POLYNESIA 

The long Malay Peninsula, the southernmost point of Conti- 
nental Asia, together with the chain of large islands, the Malay 
Archipelago, is rivalled in the richness of its flora only by equatorial 
America. The tip of the Peninsula almost touches the equator 
which bisects the great islands of Sumatra, Borneo and Celebes, 
with Java and the southern Philippines less than ten degrees 
away. 

These regions enjoy a climate that varies but little in tempera- 
ture throughout the year, and in much of the regions there is no 
marked dry season, while in many districts the rainfall is extremely 
heavy. Where, as in western Java, Sumatra and Borneo, the 
uniform high temperature and heavy rainfall are combined with 
rich alluvial or volcanic soils, there results a luxuriance of vegeta- 
tion that can scarcely be rivalled anywhere, and these regions 
are a veritable botanist's paradise. 

The Peninsula is traversed by a central mountain range, rising 
to a height of 7,000-8,000 feet, but for the most part much lower. 
This range is composed mainly of granite, but there are more or 
Less extensive limestone deposits in some districts. These lime- 
stone formations sometimes contain extensive caves, which are 
interesting biologically, as they harbor a number of peculiar 
species of animals. 

At the foot of the central mountain range is a coastal plain, 
wider along the east coast than on the west side. This coastal 
plain is (or was) heavily forested for the most part. Along the 
west coast are extensive mangrove formations and swamps, with 
very little sandy shore, while the eastern coast has many sandy 
beaches. 

Until comparatively recent times, the vegetable resources of this 
region had been but slightly exploited, except for local consump- 

200 



THE PALAEOTROPICS 201 

tion. The natives cultivated the usual tropical food-plants, 
especially the fruits, which include the choicest of all tropical 
fruits, the mangosteen and durian. 

Some fifteen or twenty years ago, however, rubber plantations 
were established, and so profitable did they prove, that soon most 
of the accessible lowland forest was cleared and planted to Para- 
rubber (Hevea Brasiliensis) . So great has been the subsequent 
development of the industry, that already there is great over- 
production, and prices have fallen to a point which lenders many 
plantations quite unprofitable. 1 

Ten years ago, the writer travelled through this region, and on 
all sides the forests were being felled, and the trees burned to get 
rid of them in order to make room for planting rubber. Only 
occasionally along the railway was it possible to see bits of the un- 
touched forest. From these remnants, however, it was plain that 
the original forest was a very rich one, with a great variety of 
lofty trees, and extremely luxuriant growth of lianas and epiphytes, 
with an undergrowth containing many ferns, and other herbaceous 
growths. Among the latter wild bananas were conspicuous, as 
well as the somew r hat similar members of the ginger family. 
Aroids, both terrestrial and climbing species, were abundant and 
conspicuous. 

This is a typical rain-forest, and practically no deciduous species 
occur, such as are so characteristic of the monsoon forests of Burma 
and Indo-China. 

Palms in great variety are characteristic of the true Malayan 
flora, and form a notable feature of the vegetation. Some are 
dwarf species, comparable to the scrub palmettoes of our southern 
states, and occur in the swamps and low ground. Others are lofty 
trees with crowns of giant fan-shaped, or more commonly pinnate 
leaves. The genera are mostly distinct from those of Africa and 
India. Among the common dwarf-palms are species of Areca and 
Pinanga, while in the mangrove swamps, the Nipa (X. fruticans), 
is very common. The latter is wide-spread through much of the 
Indo-Malayan region, and is extensively used for thatch and 
mats, as well as for its fruit. 

1 Since the above was written, the action of the British Government restricting 
the export of rubber from the East Indian plantations, has greatly increased the 
market price. 



202 



OUTLINE OF PLANT GEOGRAPHY 



In low ground may be seen large clumps of the "Nibong" 
(Qncoaperma horrida), a beautiful palm with slender trunk and 
graceful feathery leaves, but with an armor of formidable spines 
that effectually protects it. One of the most beautiful of the 
Malayan palms is the " sealing-wax " palm (Cyrtostachys Lacca), 
whose smooth sheathing leaf-bases are a vivid vermilion scarlet. 




A B 

Fig. 57. — Lowland vegetation, Malay Peninsula. 
A. Palms (Oncosperma sp.). B. Ferns (Gleichenia linearis). 

Many species of palms, aside from the coconut which is every- 
where cultivated, are very important both for food, and for many 
constructive purposes, e. g., cordage, thatch and timber. 

The sugar-palm (Arenga saccharifera) is one of the most striking 
species, with immense pinnate leaves, 25 feet or more in length. 
Its sap yields an excellent sugar, but is commonly fermented to 
form palm-wine. Another wine-palm is Caryota wrens. The 
genus Caryota has about ten species in the Indo-Malayan regions, 



THE PALAEOTROPICS 



203 



stately palms with enormous bi-pinnate leaves unlike those of 
any other palms. Fan-palms are much less abundant, the com- 
monest belonging to the genera Livistona and Licuala. 

In the wet jungles of the coastal plain the climbing rattan-palms 
are extremely abundant, and comprise a large number of species 
belonging to several genera, of which much the most important is 




Fig. 58. — Rattans, botanical gardens, Buitenzorg, Java. 

Calamus. They form impenetrable thorny thickets and some of 
them reach an incredible length, looping from tree to tree for 
hundreds of feet, and probably exceeding in length any other 
member of the vegetable kingdom. The rattan of commerce is 
the stem stripped of its outer tissues, and this, with the bamboos, 
which also reach their maximum development in the Malayan 
regions, furnish the staple building materials for the Malayan 
dwellings, as well as for endless other uses. 

Ferns are abundant in the lowland forest, among them some 
small tree-ferns; but, as elsewhere in the tropics, ferns arc still 
better developed at higher altitudes, although certain types, like 
the climbing ferns {Lygodium) , are perhaps more abundant in the 
lowland forest. 



204 OUTLINE OF PLANT GEOGRAPHY 

While showy flowers are not abundant in the rain-forest, 
occasionally there is a brilliant mass of color, when some great 
creeper or t pee bursts into bloom. The writer recalls two especially 
striking examples of this seen on the railway journey between 
Penang and Kuala Lumpur. This was in December. The first 
was a giant creeper (Bauhinia sp.), which was not infrequent, and 
reached to the tops of the tall trees, where it burst into a blaze of 
brilliant orange. The other was a moderate sized tree, a species of 
crape-myrtle (Lagerstroemia sp.) almost hidden by the mass of 
lilac-purple flowers. 

Morning glories (Ipomoea spp.), are common, and now and 
then on the railway embankment, a pretty pink ground-orchid 
(Spathoglottis sp.) was noted, as well as a number of other pretty, 
if not remarkably striking flowers, some, no doubt, introduced 
species. 

An occasional screw-pine was noted in the forest, but these are 
much commoner in the Malayan region as strand-plants, than in 
the forest, although there are forest species also. 

Singapore 

The island of Singapore, separated from the tip of the Peninsula 
by a narrow strait, is familiar to every visitor to the Far East, 
as it is the great centre for travel in the East Indies. It is at once 
apparent that we are in the heart of the tropics. Almost on the 
Line, the constant heat and high humidity are reflected in the 
rank luxuriance of the vegetation. The gardens are overflowing 
with a wealth of gorgeous flowering trees and shrubs, orchids, 
palms, and all the other choicest products of the equatorial zone. 
The markets are filled with the many fruits for which the Malayan 
tropics are famous. With the oranges, pineapples, and bananas, 
are the papayas and avocados of America, and the native 
mangosteen and durian, as well as many less known fruits and 
vegetables. 

The mangosteen and durian, are often pronounced the finest of 
all fruits. The former (Garcinia mangostana) , in shape and size 
resembling a small tomato, is a dark maroon in color, the deep-red 
thick rind enclosing about half a dozen segments, something like 
an orange, each segment composed of a snow-white juicy pulp 
of delicate and delicious flavor. The durian (Durio zibethinus) 



THE PALAEOTROPICS 



•Jl lo 



is a very different type of fruit, and on account of its powerful 
odor, rather suggesting a skunk, it must be admitted, many per- 
sons cannot be induced to taste it, and thus miss enjoying a fruit 
which is quite without a rival, and almost alone worth a trip to 
the Far East. The Malays are passionately fond of the Chilian, 
and in its season the heaps of the big spiny green fruits in the 




A B 

Fig. 59. — A. A characteristic Malayan palm (Caryota sp.); B. Dipterocarp left in 
a rubber plantation near Quala Lumpur, Federated Malay States. In front 
of the tall tree is a young rubber tree (Hevea Brazilicnsis). 

market make their presence evident far and wide. Wallace in 
his "Malay Archipelago" gives an admirable description of this 
delicious fruit, quite the best that has been written. 

Among the other common fruits are several species of Nophe- 
lium, related to the Chinese lichi. The commonest is the " Ram- 
butan," a fruit about the size of a large plum, with a shaggy crim- 
son rind enclosing an oval mass of juicy white pulp with a single 
big seed. 



206 



OUTLINE OF PLANT GEOGRAPHY 



Singapore is now pretty well cleared of forest except for some 
small nacts on Bukit Tima, the principal hill on the island, and a 
tract connected with the very interesting botanical garden. The 
forest contains some palms, mostly rattans, and a variety of trees, 
among which may be mentioned species of Melaleuca, Terminalia, 

Albizzia, Eugenia, Diospyros, 
Flacourtia, Calophyllum, and 
others, including an oak. 
Among the lianas, the most 
prominent, aside from the rat- 
tans, were species of Uncaria, 
Bauhinia, and Derris, — all 
Leguminosae. 

The garden contains an ex- 
tensive collection of plants, 
both native and exotic. The 
collection of palms comprises 
about 250 species, and there 
is an unusually fine collection 
of ferns and orchids. The 
pitcher plants (Nepenthes) 
especially characteristic of the 
region, are particularly in- 
teresting. 

The mountain forests of the 
Peninsula are to a great ex- 
tent still intact, and afford a 
most interesting study to the 
botanist. The writer made 
brief visits to two localities, 
the Pahang Gap, northwest of Kuala Lumpur, and the Taiping 
Hills in the northern part of the Peninsula. 

Up to about 3,000 feet the vegetation is decidedly tropical in 
composition. The trees are often very tall, sometimes 150-200 
feet high, and the straight smooth trunks may be 5-6 feet in di- 
ameter, although usually less. As in India, the Dipterocarps are 
much in evidence; Shorea, Dipterocarpus, Balanocarpus, and 
others. Figs, wild bread-fruit ( Artocarpus) , and many Legumi- 
nosae, e. g., Afzelia, Pterocarpus, Pithecolobium, Albizzia, etc., as 




Fig. 60. — Tree-ferns (Alsophila glauca), 
Taiping Hills, Federated Malay 
States. 



THE PALAEOTROPICS 207 

well as a variety of trees belonging to many families. I !oniferoufl 
trees are not common, bat an occasional huge Kauri-pine {Agathu 
loranthifolia) is met with, and species of Podocarpus and Dac- 
rydium members of the yew family occur. Rattans arc every- 
where abundant, and in the Pahang region, bamboos were partic- 
ularly numerous, in some places extensive groves of tall bamboos 
occupying the ground to the exclusion of everything else. The 
number of bamboos in the Malayan region is very great, and 
among them are species like the giant bamboo (Dendrocalamus 
giganteus) over a hundred feet high, with stems nearly a foot 
through. The bamboo groves are extremely beautiful, with their 
graceful drooping plumes of leaves, especially when they line the 
banks of some clear mountain stream. 

The vegetation of the Taiping Hills, is even more luxuriant 
than that of the Pahang Gap. At 3,000 feet elevation the forest 
was remarkable for the great profusion of lianas and epiphytes, 
indicating a very heavy rainfall, which was also shown by the rich 
development of ferns, mosses and liverworts. Many of the ferns 
were epiphytes, and included a number of delicate filmy ferns 
(Hymenophyllaceae) . Of the terrestrial ferns, the genus Gleichenia 
was especially abundant, sometimes forming dense tangles of 
interlacing wiry leaf-stalks that are very difficult to get through. 
Fine tree-ferns are also common, the most abundant being Alsoph- 
ila glauca. Another very conspicuous fern, is a species of Angiop- 
teris, a genus wide-spread in the eastern tropics, the leaves some- 
times exceeding 20 feet in length. 

Palms are much more abundant in the Taiping forest than in 
that of the Pahang Gap, while on the other hand, bamboos are 
better developed in the latter region, due perhaps to the lesser 
rainfall, as the bamboos as a rule are not so characteristic of 
regions of excessive rainfall. Of the numerous palms, large and 
small, which abound in the Taiping Hills, a very tall Caryota was 
especially notable. 

Other distinctly tropical types were the giant Aroids, some climb- 
ing up the trees, others with huge calla-like leaves rising stiffly 
from short upright trunks. Some of the Araceae of the Malayan 
region are gigantic. One of these, AmorphophaUus titan um, of 
Sumatra, has an enormous much divided leaf borne aloft on a 
thick stalk 10-15 feet high. A number of similar but somewhat 



208 



OUTLINE OF PLANT GEOGRAPHY 



smaller species are frequent in the lowland forest. The big in- 
florescences of these huge Aroids usually have a very offensive 
odor and attract swarms of carrion-loving insects which presumably 
assisl in pollination. 

Wild bananas (Musa Malaccensis, M. violacea) are abundant, 
and much resemble the cultivated ones except that the fruit has 
many seeds, and but little edible pulp. Presumably some of these 
wild bananas are the ancestors of the cultivated varieties. 




A B 

Fig. 61. — Pitcher plants (Nepenthes spp.). 
A. From Malay Peninsula. B. From Borneo. 

Not very distantly related to these are the many forms of the 
ginger family, which are exceptionally abundant in the Malayan 
rain-forest. They are often very handsome plants, with fine 
foliage and showy flowers. Characteristic genera are Zingiber, 
Globba, Costus, Amomum, Alpinia, etc. 

The epiphytic vegetation is a notable feature of the Taiping 
forest. As already mentioned this includes a large number of 
ferns, of which the big bird's-nest fern (Asplenium nidus) is the 
most conspicuous, and orchids are extremely abundant, mostly 



THE PALAEOTROPICS 209 

small inconspicuous species, but some of them of great beauty. 
Rhododendrons with white or scarlet flowers may be seen high 
up in the branches of the trees. The numerous epiphytic rho- 
dodendrons are a common and beautiful feature of the Malayan 
mountain forests. Sometimes growing as epiphytes, but more 
common on the ground, or climbing over the lower vegetation, 
are several species of pitcher plants (Nepenthes), whose centre of 
development is in the mountains of Malaya and Borneo. The 
graceful vases or urns, suspended from the leaf tendrils, are beauti- 
fully colored, and sometimes a foot or more in length. No plant 
structures are more remarkable than these curious organs. The 
climbing screw-pines (Freycinetia) are common and conspicuous, 
but Pandanus is much less in evidence. 

The numerous species of Aeschynanthus (Gesneraceae), with 
very showy scarlet flowers something like a snapdragon, are among 
the most attractive of the epiphytes, but even more beautiful are 
species of Medinilla (Melastomaceae) whose great clusters of pink 
flowers subtended by big rosy bracts, at once attract attention. 
Some very handsome Begonias, too, occur as epiphytes in the wet 
mountain forests. 

A visit was made to the summit of the main range, at Pahang 
Gap. At this elevation, about 4,000 feet, quite a different type of 
forest was encountered. The trees are much smaller and trunks 
and branches covered with a heavy growth of mosses, liverworts, 
and other epiphytes, mostly of rather small size. In this "moss- 
forest" were collected a number of interesting bryophytes, which 
found here a congenial habitat. 

The exposed summit of the ridge was occupied largely by open 
boggy places, with stunted small trees and shrubs. In the bogs 
were masses of peat-mosses (Sphagnum) in which were growing 
rhododendrons and other members of the heath family; orchil-. 
and other bog-plants, suggestive of the northern peat-bogs; but 
with these were strange ferns, and clambering over the bushes 
were magnificent Nepenthes with pitchers as big as a pint 

measure. 

Of the ferns, several of the Gleichenias are wide-spread species, 
but two of the most conspicuous ferns, Dipteris conjugate, and 

Matonia pectinata, are less common, and the latter is restricted to 
rather limited areas on the mountains of the Peninsula and the 



210 OUTLINE OF PLANT GEOGRAPHY 

larger islands of the Archipelago. Both are very handsome with 
large fan-shaped leaves borne on tall stalks. Matonia is especially 
interesting as it is almost the only survivor of a very old family, 
and for a long time was known only from a single locality, Mt. 
Ophir in Malacca. 

While the Malay Peninsula is rich in ferns, and epiphytic mosses 
and liverworts, the ground liverworts are less abundant than 
might be expected from the general luxuriance of the vegetation. 
Whether or not this is due to the prevailing character of the soil, 
is a question. The rocks of the Peninsula are mostly granitic, 
and the coarse gritty soil resulting from the decomposition of these 
rocks does not seem to meet the needs of these plants. In the 
limestone region, there were species not found elsewhere, but no- 
where in the Peninsula were they so abundant as in the volcanic 
regions of Java and Sumatra. 

The Sunda Islands 

The three great islands adjacent to the coast of the Malay 
Peninsula, Sumatra, Borneo, and Java, exhibit in the highest 
degree, the exuberant development of the equatorial Malayan 
vegetation. Both the plant and animal life indicate that these 
islands, at no very distant epoch, were united to the Asiatic main- 
land. 

Borneo, the largest of these islands, separated from Singapore by 
about 400 miles of the shallow Java Sea, is still very incompletely 
known, as much of its nearly 300,000 square miles is an unexplored 
wilderness. The coastal regions of Sarawak in the west have been 
quite extensively explored botanically, as the country has been 
under British domination for nearly a century, and is compara- 
tively easy of access. 

Borneo is to a great extent mountainous, but there are large 
expanses of lowland swamp and forest in the coastal districts. 
There is a central range of mountains, attaining a maximum height 
of about 10,000 feet, and from this range, others diverge, with 
plateaus lying between the ranges. The main range is composed 
partly of ancient crystalline schists, and in British North Borneo, 
Kinabalu, the highest mountain in the island, is a granite mass, 
rising to 13,698 feet. Deposits of limestone are found in some 



THE PALAEOTROPICS 211 

• 
localities, as well as volcanic formations; but there are none of the 
active volcanoes which are such a marked feature of Java and 
western Sumatra. Indeed the geology of Borneo is more like thai 
of the Malay Peninsula, and there is also much in common in the 
vegetation between Borneo and the Peninsula. 

As one approaches Sarawak from the west, the coast presents a 
very picturesque aspect, bold mountains coming down to the sea in 
places. Between two of these mountains, Mattang and Santu- 
bong, the Sarawak River, upon which is situated the principal 
town, Kuching, makes its way to the sea. Santubong is especially 
impressive, rising abruptly from the water to a height of 3,000 
feet, its steep flanks clothed with primaeval forest. 

The low banks of the delta are for the most part densely covered 
with mangroves, and the mud flats exposed at low-tide, are the 
haunt of crocodiles and other less formidable creatures, like the 
grotesque mud-fish, which climb about the exposed mangrove 
roots like lizards, while myriads of bright blue crabs scuttle about 
over the mud, and if the tide is low, cannot fail to attract atten- 
tion. 

Further up the river, the numerous narrow channels which 
traverse the mangrove formation, are lined with dense growths 
of the Nipa-palm, whose leaves are indispensable for thatch, or 
for the manufacture of the basket-work panels which form the 
sides of the native houses. Behind the Nipa zone, another beauti- 
ful palm, the "Nibong" (Oncosperma filamentosa) is common, and 
their slender stems and feathery crowns form a conspicuous and 
beautiful feature of the shore vegetation. 

With the decreasing salinity of the water as the river is ascended, 
the mangroves gradually disappear and the solid river banks are 
covered with a dense growth of trees and shrubs in great variety. 
Back of the belt of shrubs and low trees there appear in places the 
tall trees of the high forest, the outposts of the prodigious forests 
which cover most of the wet lowlands of Borneo. 

Wherever a native village appears on the river bank, coco- 
nuts, sago-palms, bananas, bread-fruit, and the other common 
cultivated trees are seen between the wild growths of the shore. 

The trees and bushes of the jungle lining the river banks are 
smothered in a tangle of climbing plants and epiphytes in astonish- 
ing variety and profusion. Ferns, orchids, and other epiphytes 



212 OUTLINE OF PLANT GEOGRAPHY 

cling to the trunks and branches of the trees, often almost entirely 
concealing them, evidence of the extreme humidity of the climate 
of these lowland forests. 

Kuching, the capital of Sarawak, lies within a single degree of 
the equator, which almost bisects Borneo. With an annual 
rainfall of 160 inches, and an almost constant hot-house tempera- 
ture, Sarawak has a true equatorial climate, and the vegetation 
i xhibits a luxuriance that very few regions, even under the equator, 
can rival. All the common tropical products abound, and reach 
great perfection. Palms of many sorts, bananas, pineapples, 
bamboos, orchids, grow in rich profusion, and the gardens show a 
wonderful wealth of rare and beautiful trees and shrubs. The 
trunks of the palms and the trunks and branches of other trees 
are laden with epiphytes in bewildering profusion, while giant 
creepers, with flowers of every hue, are draped over every fence, 
or climb high into the trees. 

While the forest has been cleared in the immediate vicinity 
of Kuching, one does not have to go far to see samples of the orig- 
inal forest, whose exploration is by no means easy, as the lowlands 
aif Largely swamps, or else overgrown with impenetrable thickets 
of rattans and other troublesome undergrowths. 

Where the original forest has been removed, a second growth 
quickly springs up, composed of many species of trees, and a dense 
tangle of bushes, lianas, ferns, and a great variety of herbaceous 
species. 

As might be expected in so humid a climate, ferns are much in 
evidence. Among the commonest are species of Gleichenia. We 
have already referred to the great development of Gleichenias 
in the Malay Peninsula, which in this respect, as well as some 
others, shows a marked resemblance to Borneo. The climbing 
ferns (Lygodium spp.) are also common and very beautiful. 

One of the commonest and showiest shrubs of this region is 
Wormia pidcheUa (Dilleniaceae), whose big yellow flowers are 
seen everywhere. The genus Wormia is very abundant through- 
out Malaya, and at once attracts attention. The Acanthus family, 
and the Melastomaceae, the latter with pretty pink or purple 
flowers, are among the commonest of the more showy shrubs, and 
now and then one sees a scarlet Aeschynanthus climbing up the 
trunk of a tree or established as an epiphyte. 



THE PALAEOTROPICS 213 

The pitcher plants (Nepenthes), are extraordinarily abundant 
in Borneo, and may be found at all elevations from sea-level to 
an altitude of 8,000 feet. Sonic are low-growing terrestrial species, 
but more commonly they are climbers or epiphytes. In most 
species, the pitchers are developed at the end of the tendril formed 
by a prolongation of the midrib of the leaf; but in the young 
plants, and also in some terrestrial species, the pitcher seems to 
represent the whole leaf, and the plant may consist of a rosette 
of these urn-shaped organs. There seems to be little doubt that 
the fluid in the pitcher contains definite enzymes similar in their 
action to pepsin, and capable of a true digestion of the insects and 
other small animals that may be captured. YVh ether or not, as has 
been stated, the Malays use this fluid as a corrective for indigestion, 
the writer will not venture an opinion. Young plants with pitchers 
no bigger than a thimble are common along the sides of ditches 
and on wet banks, while it is said the great N. Rajah, from Mt. 
Kinabalu, has pitchers, perhaps one might say jugs, holding two 
quarts. The Malay Peninsula, next to Borneo, probably has the 
greatest number of species, but they are found also throughout the 
whole Malay Archipelago, from northeastern Australia and New 
Guinea, to the Philippines, a single species also occurring in 
Ceylon. 

Travelling in Sarawak depends very largely upon water-ways, 
as there are practically no roads, except in the immediate vicinity 
of the towns. If one leaves the streams, one must proceed on foot 
through the swamp and jungle, not always a pleasant operation, 
as the low ground is almost always more or less under water. 
Such excursions into the magnificent forests are not only fatiguing 
but include, incidentally, the discomfort of swarms of mosquito 
and myriads of land-leeches, which are especially numerous and 
voracious in the Bornean forest. 

Among the rare plants of Sarawak are several ferns. One of 
these, Matonia sarmentosa, is known only from one locality, the 
Bidi Caves, limestone caverns where it hangs down in long festoons 
only to be reached by long ladders used by the natives for collect- 
ing the edible birds' nests which are found in these same caves. 
Another fine species, the principal object of the writer's visil 
to Sarawak, is Macroglossum Alidae, one of the small order Marat- 
tiales. This, or a similar species has since been collected in Su- 



214 OUTLINE OF PLANT GEOGRAPHY 

matra. It is a magnificent plant, with great palm-like leaves four 

yards long. 

The two mountains guarding the delta of the Sarawak River, 
Mattang and Santubong, arc fairly easy of access, and their 
floras arc extremely interesting. Mattang, which for some reason 
is avoided by the natives, has never been denuded of forest, and 
affords an admirable opportunity of studying the primitive vegeta- 
tion of the region. 

The forest is a very rich one. Very tall trees, including many 
Dipterocarpaeeae, like those of Indo-China and the Malay States, 
are bound together by great lianas, like huge cables, or with climb- 
ing Araceae and other creepers, clinging to their trunks, which 
with the branches are often smothered in a profusion of epiphytic 
growths of all kinds. 

Below the tall trees are smaller ones, with an extraordinary 
variety of palms, giant ferns, wild bananas, rattans and a host 
of other striking plants. The Dipterocarp forest at the foot of 
the mountain is more open, being freer from undergrowth, and 
easier to get through; but as one ascends the mountain, the under- 
growth is very dense, and one must exercise great care not to lose 
one's way in the thick jungle. 

The wet banks along the trail are covered with beautiful ferns, 
liverworts and mosses, and although flowers are not very abundant 
or conspicuous, there were several worthy of notice. One of the 
prettiest was a Didymocarpus (Gesneraceae), with small fox- 
glove shaped flowers, pale purple in color, borne on slender stalks 
rising from a rosette of dark green, almost black leaves, veined 
with snowy white. These dainty flowers grew abundantly on the 
mossy banks associated with delicate ferns, and made an ex- 
quisite picture. An occasional showy orchid, and some pretty 
Begonias were seen, and in one place, a number of plants of a 
pale yellow rhododendron (R. salici folium) . In the upper forest, 
a handsome Ixora, with scarlet flowers, somewhat like Bouvardia, 
was abundant. 

Mt. Mattang has an especial interest to the botanist, as Pro- 
fessor Beccari, the great authority on palms, spent a long time 
here, and many of his species were first collected on this mountain. 

The Dipterocarpaeeae, so important as timber-trees through- 
out the Indo-Malayan region, are represented by many species in 



THE PALAEOTROPICS 215 

Borneo, many of great size. There are also other large trees, 
especially Leguminosae. One of these, the "Tapang' : (Abauria 
excelsa) is the tallest tree of the Bornean forest, a specimen 230 feet 
high having been measured. 

Many species of Ficus are common, as well as species of Arto- 
carpus, including the bread-fruits and Jack-fruit. Both the durian 
and mangosteen are represented by wild species. Rather un- 
expectedly there are several species of oaks, mostly in the moun- 
tains, but some at sea-level, as is also the case in the Malay 
States. 

The coniferous trees of Borneo are few in number, and exclu- 
sively of southern types. The dammar-pines (Agathis), Podocar- 
pus and Dacrydium are the only Bornean genera. 

Borneo probably has more species of palms than any other 
area of equal extent; but many of them are small and relatively 
inconspicuous, or else they are climbing species of the rattan-type, 
which hardly suggest palms. There are, it is true, a considerable 
number of tall species, like the Sago-palm and Nibong; but as a 
rule, they do not dominate the vegetation to the same extent as in 
equatorial America. About 130 species have been described, 
mostly by Beccari, and all but 20 are peculiar to Borneo. 

Many screw-pines occur in Borneo both as strand-plants, and 
in the forest up to 4,000-5,000 feet elevation. 

The Araceae are also highly developed, and much resemble those 
of the Malay Peninsula. 

One naturally expects to find many orchids, and, in fact, they 
are extremely numerous; but as every collector who has visited 
the tropics, knows, the showiest orchids are usually rare, and 
seldom abundant enough to make a striking display. Most 
species are insignificant, and would be overlooked by any but a 
botanist. 

There are, of course, many very beautiful orchids in Borneo and 
other parts of the Malayan Archipelago, many of these being 
prized in cultivation. In the gardens of Singapore and Sarawak 
two handsome species are often seen, Vanda tens and Arundina 
speciosa. These are both ground orchids, and apparently easily 
grown. The genus Vanda includes many handsome species, some 
of which, like the Javanese V. tricolor, are often seen under glass 
in Europe and America. Perhaps the most striking of the Malayan 



216 OUTLINE OF PLANT GEOGRAPHY 

orchids is the "tiger-orchid" {Grammatophyllum speciosum) . This 
is a giant among orchids, and may be seen in great perfection in 
the famous botanical gardens at Buitenzorg in Java, where its 
pendent leafy shoots hang down from the trees to a length of ten 
feet or more. The numerous upright flower-stalks as tall as a man, 
bear many big brown and yellow striped blossoms. The genus 
Dendrobium is one of the largest in the eastern tropics, and many 
species are extremely beautiful and highly prized by collectors. 
A very interesting species is D. crumenatum, known in the British 
possessions as " pigeon orchid." It is very abundant and has the 
remarkable habit of flowering simultaneously over a large area, 
and only for a single day, when the long sprays of fragrant white 
flowers may be seen by thousands. The next day they are faded, 
and not a single fresh flower can be seen. 

Among the noteworthy ferns of Mattang were species of Kaul- 
fussia, Angiopteris, and Schizaea, and some fine tree-ferns (Al- 
sophila contaminans). The handsome fern Dipteris conjugate 
was especially fine, the big fan-shaped leaves with stalks at 
least 8 feet high. Of the epiphytic ferns, the Hymenophyllaceae 
were not especially abundant, although represented by a number 
of species. Epiphytic species of Lycopodium included several 
conspicuous species like L. Phlegmasia, and an occasional speci- 
men of the curious Psilotum flaccidum, with leafless flattened, 
pendent shoots was seen. 

At the summit of Mattang is a small area of comparatively 
open ground, with various sedges and grasses, but these are 
scarce in the heavy forest which covers most of the mountain. 

Santubong, on the opposite side of the Sarawak delta, from 
Mattang, is much steeper, and the forest is more open and drier. 
At the summit, however, it is boggy, with abundant Sphagnum, 
like that of northern peat-bogs. The stunted trees are covered 
with a very heavy growth of epiphytes, among w 7 hich were two 
very beautiful rhododendrons, and one of the finest pitcher- 
plants (Nepenthes Veitchii), which is prized in cultivation for 
its magnificent pitchers. 

The beach skirting the foot of Santubong offers an excellent 
example of the Malayan strand-flora. Creeping over the sandy 
beach was the ubiquitous Ipomoea pes-caprae, found on pretty 
much every tropical beach the world over, and further back 



THE PALAEOTROPICS 



217 



was a belt of trees and shrubs including many of the common 

Malayan strand species. 

The largest trees were Casuarina, a genus especially developed 
in Australia, but extending as far as India. These peculiar 
trees have no leaves, but the slender green twigs look very much 
like pine-needles, and the tree suggests a long-leaved pine. Another 
characteristic tree is Term.inalia Catappa, with branches arranged 
in regular tiers, and bearing very large glossy leaves. A rather 



. 











I _ 



v , 




<;.« 




A B 

Fig. 62. — Strand vegetation at foot of Mt. Santubong, Sarawak, Borneo. 
A. Casuarina sp., Tenninalia Catappa B. Panda n us sp. 

smaller and very beautiful tree, with leaves somewhat like those 
of Terminalia, is Barringtonia speciosa. The large four-angled 
fruits are conspicuous, and specially adapted for long journeys 
by sea, like the coconut, which explains the wide distribution 
of this tree throughout Malaysia. Another even more widely 
distributed species is the yellow tree-hibiscus (H. tiliaceus)—* 
denizen of most tropical beaches from the Malay Archipelago 
to Hawaii. The showy yellow flowered Wormia, already men- 
tioned, is also very common, and a screw-pine with big red fruit- 
cones, looking like ripe pineapples, was very abundant. Asso- 



218 OUTLINE OF PLANT GEOGRAPHY 

dated with these trees were a number of leguminous shrubs 
wit h yellow or purple flowers, and climbing over trees and shrubs 
were various lianas, including several showy Ipomoeas, and a 
species of Gnetum, with salmon-pink berries. The latter repre- 
sents a small family of gymnosperms, the Gnetaceae. 

Forest Trees 

As already indicated the most important trees are the Dip- 
terocarps, but besides these is an extraordinary variety of other 
large trees. The most important families are the Rubiaceae, 
Leguminosae, Ebenaceae, Sapotaceae, Artocarpaceae, Tiliaceae, 
Bombacaceae, Dilleniaceae and Euphorbiaceae. The Rubiaceae 
take first place in the Bornean flora, the Orchidaceae second. 

Sumatra 

Separated by the Straits of Malacca from the Malay Pen- 
insula, is the great island of Sumatra, about 1,100 miles long, 
by 250 in breadth, and almost exactly bisected by the equator. 

The topography of the island is comparatively simple. Parallel 
with the west coast, and descending to it abruptly, is a mountain 
range, in places exceeding 10,000 feet elevation. Between this 
range and the east coast is an extensive low alluvial plain. 

The mountain ranges are composed largely of Palaeozoic 
rocks, granites, schists, quartzite, slate and limestone, but there 
are later deposits also, and some extensive volcanic formations 
including a number of active volcanoes, some of them approach- 
ing 10,000 feet altitude. 

The climate is of the true equatorial type, with very little 
variation of temperature, and for the most part abundant rain- 
fall. The west coast has a heavier rainfall than the east, approach- 
ing 200. inches annually at some points. The driest districts 
are in the northeast on the lee-side of the mountains. 

While the vegetation has been pretty well investigated in 
some parts of Sumatra, much of the country is still very little 
known. The fertile eastern plains have been cleared of the 
heavy forest over considerable areas, and the usual tropical 
crops are grown. Of late years Sumatra has become a very 
important source of rubber, of which extensive plantations 
now exist. Tobacco culture is also a very important industry. 



THE PALAEOTROPICS 219 

The cultivated districts are mostly in the fertile eastern plains, 
but extensive areas still await development. Although nearly 
four times the area of its neighbor Java, it has only about one 
sixth the population, and like Borneo, the development of its 
immense resources has only begun. 

In the northern part the mountains approach the eastern coast 
so that the coastal plain is much narrower than further south, and 
in this region, the original forest has pretty well disappeared from 
the lowlands which are largely under cultivation. Tobacco is the 
chief crop, for which this Deli district is famous. 

The most important town, Medan, is some distance inland, the 
immediate coast being occupied by extensive mangrove forma- 
tions, composed of several species. There are also Nipa swamps, 
with the big fern, Acrostichum aureum, and back of this the grace- 
ful Oncosperma palms, as in Borneo. 

Between the swamps of the coast and Medan, is a cultivated 
region, with the usual tropical growths, and in places, extensive teak 

forests. 

This region is a rich alluvial plain presumably covered, originally, 
by heavy forest, now destroyed ; but much of the land is covered 
with second growth jungle. Tobacco, which is most carefully 
handled and transplanted, is grown only for a short time on the 
same ground, which is then allowed to grow up to jungle for several 
years when it is again cleared for tobacco; so that only a fraction 
of the arable land is in use at one time. 

The soil is very rich, and the jungle springs up quickly and com- 
prises a great variety of trees and shrubs, as well as herbaceous 
flowering plants and ferns. 

The writer had an opportunity of making a brief sojourn in the 
mountains west of Medan. Bandar Baroe, at an elevation of 866 
metres has still some remains of the original forest, which has prac- 
tically disappeared from the adjacent lowlands. At this elevation it 
is noticeably cooler than at Medan, and there is evidently a fairly 
heavy rainfall, although decidedly less than on the western side 
of the mountains; and the forest was much less luxuriant than at 
similar elevations in western Java, Borneo, and the Malay Pen- 
insula. . Some of the trees, however, were very large, especially 
some gigantic figs of the banyan type. 

In general the vegetation of this part of Sumatra, is quite 



220 



OUTLINE OF PLANT GEOGRAPHY 



similar to that of the Malay States across the Straits of Malacca, 
but less luxuriant. There is a considerable development of lianas, 
including species of Vitis, various climbing Araceae, e. g., Pothos, 
Scindapsus, and a good many small rattans. 

Palms are not conspicuous, although there are a good many 
small species, and occasionally a sugar-palm (Arenga sp.) with 
enormous feathery leaves. 



.^"JS 




Fig. 63. — Rain-forest vegetation, Bandar Baroe, Sumatra. Wild banana (Musa 

sp.); wild ginger (Eletteria sp.). 

In the rain-forest especially along the small streams is a rich 
vegetation of gingers, bananas, and other similar plants. A very 
common one is an Amomum, a ginger with leafy stems two or 
three yards high, the leafless flower stalks arising separately from 
the rhizomes. Others, e. g., Costus and Alpinia have showy flowers 
suggesting orchids. The latter are represented by many species, 
some of great beauty, e. g., Caelogyne, Spathoglottis, Arundina; 
and a small Nepenthes was also noted but the latter genus is much 
more abundant in some other parts of Sumatra. 



THE PALAEOTROPICS 



221 



Among the more abundant flowers, were numerous pretty 
balsams (Impatiens spp.), Melastoma, Clerodendron, Didymo- 
carpus, and several Begonias and Solanums. 

Screw-pines both Pandanus and the climbing Freycintia, 
were abundant. Tree-ferns were not uncommon, and the big 
Angiopteris was very abundant, and especially luxuriant, with 
huge fronds four or five yards long. Contrasted with these are 




a B 

Fig. 64. — Rain-forest vegetation, Bandar Baroe. 
A. At left, young palm (Caryota sp.). B. The large fern is Angiopteris sp. 

tiny epiphytic Hymenophyllaceae, only an inch or two high. 
Many other ferns, both epiphytic and terrestrial are common. 

A number of interesting liverworts were collected at Bandar 
Baroe, which is richer in these plants than most parts of the Malay 
Peninsula, and approaches the extremely rich region of western 
Java where conditions are quite similar. Some of the rarest and 
most interesting species occur in these favored regions. 

Above Bandar Baroe, at an elevation of about 1,200 metres, 



222 OUTLINE OF PLANT GEOGRAPHY 

is an extensive plateau, a sort of moorland covered with coarse 
" lalang " grass and bracken. Except in sheltered places, trees were 
absent, but where conditions permitted, tree-ferns, palms (Car- 
yota, Arenga), and some other tropical types were noted; but with 
these were such characteristic northern plants as elder, raspberries, 
violets and several coarse Compositae. These grassy plateaus 
are said to be frequent in the mountain regions of northern Sumatra. 

The western side of the main mountain range has a much heavier 
rainfall than occurs in eastern Sumatra and the vegetation is 
said to be extremely luxuriant. In the Padang Highlands, espe- 
cially in the volcanic districts, the conditions are much like those 
in western Java, and the vegetation has much in common with that 
region. 

The forests of the southwest are said to be characterized by 
unusually large trees, especially some of the Dipterocarps. Forbes 1 
states that he measured trees whose trunks were 40-50 yards be- 
fore they branched, and some of them ten to twelve feet in diameter. 
The species were not given. The principal products of this part 
of Sumatra are pepper and dammar-gum, the latter derived from 
several species of Dipterocarps, the most valuable being that ob- 
tained from Hopea dryobalanoides. These gums are highly prized 
for fine varnishes. 

Even with its relatively scanty population, the destruction of 
the forests has been very great, owing to the very wasteful methods 
employed. Like all half-civilized peoples in a forest country the 
natives destroy the forest with no thought for the future. The 
ground is cleared, cultivated for a short time, and then allowed to 
revert to jungle, or as too frequently happens, to become invaded 
by the rank "lalang" grass (Imperata arundinacea and Saccharum 
spontaneum), which prevents the forest getting a foothold, and 
renders the land quite useless for cultivation. 

The lowland forests have largely disappeared, and one must 
usually go to the mountains to see the primaeval forest. As in 
the Malay States, the great development of rubber plantations has 
been largely responsible for the destruction of the original forests. 

Forbes 2 gives an interesting account of the flora of one of the 

1 Forbes, H. O., A Naturalist's Wanderings in the Eastern Archipelago, p. 221, 
1885. 

2 Loc. cit., p. 206. 



THE PALAEOTROPICS 223 

higher volcanic peaks, Dempo, over 10,000 feet elevation. At an 
elevation of 3,500 feet there were extensive coffee plantations, above 
which, at about 4,000 feet, the virgin forest began, and for about 
2,000 feet was extremely luxuriant, evidently much like the similar 
forests on the slopes of the great volcanic peaks of western Java. 

Flowers were scarce, except for some epiphytes and climbers, 
but he discovered one remarkable new species, a strange parasite, 
Brugmansia sp., related to the gigantic Rafflesia Arnoldi, also a 
native of Sumatra. The latter is an extreme parasite living within 
the tissues of a vine (Vitis sp.) very much like a parasitic fungus. 
The flower buds break through the tissues of the host-plant, and 
the huge flowers, sometimes nearly a yard across, look as if they 
belonged to the vine upon which they are parasitic. These giant 
flowers have a color and odor suggesting putrid flesh, and attract 
swarms of carrion-flies and other insects which doubtless serve as 
agents in pollination. Among the plants noted by Forbes in the 
lowland forest, was the gigantic arum, Amorphophallas Titanum, 
with leaves seventeen feet high I 

The forest shows the usual profusion of gingers, bananas, tree- 
ferns, palms, aroids, etc. Forbes states that this region also, is 
remarkably rich in flowering trees, one of which, Gordonia excelsa, 
has two related species in the southern Atlantic states. Above 
6,000 feet most of the palms, including the rattans, ceased, and the 
trees became smaller. These trees were mostly of the myrtle 
family, and their branches were heavily laden with epiphytes, 
especially ferns in great variety. Still higher up, long gray lichens 
became conspicuous, and Begonias, honeysuckles, and a very fine 
orchid (Dendrobium secundum) were abundant. The tall forest 
stopped at 8,600 feet, and changed to lower shrubby growths, largely 
Ericaceae. Of these, a species of Vaccinium (V. Forbcm), became 
a small tree. This was associated with scarlet rhododendrons, 
and many ferns. A few raspberries and a gentian were also noted, 
but the pitcher plants, so abundant on some of the mountains, 
were almost entirely absent. 

While the trees of Sumatra are mainly Malayan types, they 
include a single pine (Pinus Merkusii), found in the north of the 
island, and several species of oaks. Pinus Merkusii probably marks 
the southermost extension of the true pines, but Sumatra shares 
with the rest of Malaya the Kauri-pines (Agathis) and Podocarpus. 



224 OUTLINE OF PLANT GEOGRAPHY 

Java 

Probably no region in the world offers more to the botanical 
student than does Java, and because of the amazing wealth of the 
flora, and its accessibility, it has been visited by many botanists 
during the past century, and its flora is better known than that 
of any other part of the Malayan region. 

Java is preeminently a volcanic country and contains many 
active volcanoes as well as numerous extinct ones. The volcanic 
soils are extremely rich, and together with the uniform high tem- 
perature and very heavy rainfall, induce a luxuriance of vegetation 
in many parts of Java, especially in the west, that can hardly be 
matched elsewhere. 

Unlike Borneo and Sumatra, Java is very densely populated, 
and most of the available land is under cultivation. As elsewhere 
in Malaya, rice is the staple food, and is very carefully cultivated; 
but in addition to rice, practically all the tropical food-plants are 
grown, and the variety of fruits, especially, can hardly be equalled 
anywhere. In spite of the dense population, about 30,000,000 
in an area less than 50,000 square miles, there is little evidence of 
this to the casual observer in western Java. The people live for 
the most part in small villages, "campongs," composed of bamboo 
houses so hidden by the groves of palms, bamboos, and fruit-trees, 
as to be quite invisible except at close range; and from an eleva- 
tion the country appears to be covered by an unbroken forest, 
except for the larger towns and extensive rice fields. 

Under the wise administration of the Netherlands government, 
Java is probably the most successful tropical colony in the world, 
and the output of all sorts of tropical products, rubber, coffee, 
sugar, tobacco, etc., is very great, and the country is extremely 
prosperous. Among the most important products of Java is 
quinine, which, introduced from South America, has been most 
successfully grown, and by careful selection trees have been devel- 
oped which yield a much greater amount of quinine than any of 
the wild species of Cinchona. 

Java is extremely mountainous, there being very little level 
country. Along much of the northern shores are mangrove and 
Nipa swamps, but the southern side of the island has a greater 
development of sandy beaches and dunes. The high mountains 




225 



226 OUTLINE OF PLANT GEOGRAPHY 

arc all volcanic, those in the west forming a more or less continuous 
mass; at the east are several isolated peaks, including the loftiest 
mountain, Merapi, about 12,000 feet high. 

In general, the rainfall in Java is heavy, especially in the western 
mountains, and in the southern part of the island. While in all 
parts of Java, the period from November to March, the west 
monsoon, shows the greatest precipitation, there is no pronounced 
dry season, although in eastern Java the rainfall is scanty during 
several months, and the vegetation is very different from that of 
the wet western mountains. 

The approach to Batavia, the old capital, is through a swampy 
region in which the Nipa-palms are a conspicuous feature. The 
residence district, outside the old town, is attractive, the gardens 
full of fine foliage and flowers, but the surrounding country being 
closely cultivated, offers little to the botanist who is likely to seek 
the mountains as soon as possible. 

The great centre of botanical activity is the famous botanical 
garden at Buitenzorg, some forty miles from Batavia, at an eleva- 
tion of about 1,000 feet. From Buitenzorg the richest botanical 
regions are within easy reach, and together with the immense 
collections in the garden, afford unequalled opportunities for the 
study of equatorial vegetation. 

In these gardens may be seen an unrivalled collection of tropical 
plants, drawn from everj' quarter of the world. Java has been a 
centre of botanical research for more than a century, and the col- 
lectors have brought to the gardens plants from all over the Archi- 
pelago, many new species having their types now growing in the 
gardens. The conditions for tropical vegetation are ideal. The 
average temperature hardly varies throughout the year, and is 
about 78°F. A rainfall approaching 200 inches annually, an 
absence of a marked dry season, and rich soil, give these gardens 
a great advantage over any of the other important tropical 
botanical gardens. 

The country immediately about Buitenzorg is mostly under 
cultivation, but nevertheless many interesting native plants may 
be found growing outside the cultivated areas; and within a short 
distance, on the lower slopes of the great volcano Salak, a magnif- 
icent forest of the most pronounced tropical type can be found. 

Compared with the lowland forests of Sumatra and Borneo, 




03 
> 

03 



- 
O 

SJ 

c 



O 



03 






227 



228 OUTLINE OF PLANT GEOGRAPHY 

Dipterocarps are less in evidence. On the other hand the species 
of figs (Ficus) are developed to an extraordinary degree in Java, 
over a hundred species having been described, of which a majority 
arc in western Java. 

Belonging to the same family as the figs, is the famous Upas 
(Antiaria toxicaria), a very large tree, whose poisonous properties 
have been greatly exaggerated. 

The myrtle family is also abundantly represented, especially 
the genus Eugenia, while other characteristic trees belong to the 
custard-apples (Anonaceae), and the Leguminosae have many 
representatives, e. g., Albizzia, Pterocarpus, Tamarindus, Cassia, 
etc. The canary-nut (Canarium sp.) belonging to the tropical 
family Burseraceae, is a large and characteristic tree. A magnif- 
icent avenue of these is one of the features of the Buitenzorg 
garden. The silk-cotton (Bombax), durian {Durio spp.) and 
several species of Artocarpus, are characteristic of the Javanese 
forest. In the lowland forest is a wealth of palms, including many 
species of rattans, as well as some fine tall species, e. g., Oncosperma, 
Areca, Caryota, etc. 

Lianas and epiphytes are extremely abundant as elsewhere in 
the lowland Malayan jungles, and much like those in Sumatra and 
Borneo. Tall bamboos (Dendrocalamus, Gigantochloa), screw- 
pines, and fine tree-ferns, combine with the gingers, bananas, and 
giant arums, to make a magnificent undergrowth, wherever the 
shade is not too dense. 

Western Java is one of the richest regions in the world for liver- 
worts and ferns. The banks and shady ravines are full of rare and 
beautiful species, in immense variety. Tree-ferns are especially 
abundant and beautiful, some specimens of a common species, 
Alsophila glauca, being said to reach a height of 20 metres. These 
are found at a lower elevation in western Java than is usual, but 
reach their maximum development at somewhat higher elevations 
in the cooler mountain rain-forest. 

The lowland forest extends to about 2,000 feet elevation, above 
which up to about 4,500 feet, is a rain-forest, tropical in its main 
constituents, but with a considerable mixture of species allied to 
those of more temperate climates. 

A forest of this character may be seen in great perfection on 
the great volcanic mass, the Gedeh, not far from Buitenzorg. 




229 



230 OUTLINE OF PLANT GEOGRAPHY 

On this mountain, at about 4,000 feet elevation, is a botanical 
garden with accomodations for visiting botanists; and Tjibodas, 
the site of this garden, is familiar to many botanists who have 
explored the virgin forest which immediately adjoins the garden. 
From this point to the summit of Pangerango, 10,000 feet high, 
is an unbroken primaeval forest, in which one may study at his 
convenience the wonderfully rich vegetation of this great volcano. 

The lower forest comprises over a hundred species of trees 
belonging to many genera. The figs and myrtles, so numerous 
in the lowland forest are much less abundant, while chestnuts, 
oaks, maples, Viburnum, and Vaccinium, recall the forests of 
the north temperate zone. The tallest tree of this region, the 
"Rasamala" (Altingia excelsa), is a near relative of the American 
Liquidambar. Magnificent specimens of this noble tree are 
growing close to the garden, and high up on the branches one 
catches glimpses of the bright orange flowers of an epiphytic 
rhododendron (R. Javanicum). 

A number of trees belong to genera characteristic of the forests 
of Atlantic North America. Of these the beautiful Gordonia 
excelsa with its abundant big white flowers, is the most conspic- 
uous. Others belong to the genera Nyssa, Celtis and Lindera. 
Other representative genera of this forest are Symplocos, Schima, 
Trema, Elaeocarpus, Flacourtia, Antidesma, Cedrela, Wein- 
mannia, Myrsine, Pandanus, Vernonia, Michelia. The only 
gvmnosperms are two species of Podocarpus. 

(limbing plants are not so abundant as in the lowland forest, 
but there is an immense development of epiphytes, ferns, mosses, 
orchids, rhododendrons, and many others. Common and con- 
spicuous are the species of Aeschynanthus with scarlet flowers. 

Of the epiphytic ferns, the great bird's-nest fern (Asplenium 
nidus) is the most conspicuous. This fern sometimes has attached 
to its base another remarkable epiphytic species, Ophioglossum 
pendulum, and other epiphytic ferns are many Hymenophyllaceae, 
1 ttt<i riu spp., Polypodium spp., and others. There are several 
epiphytic species of Lycopodium, e. g., L. Phlegmaria, and also 
Selaginella. 

Flowers are not very abundant, but sometimes a showy orchid 
i- met with, and some extremely pretty balsams (Impatiens 
spp.) are very common. 



THE PALAEOTROIMCS 

Probably no tropical mountain has been more thoroughly 
explored than the.Gedeh; and no mountain better illustral 
the changing zones of vegetation as one ascends from the bs 
to the summit, 10,000 feet above sea-level. 

The forest, which at Tjibodas, about 4000 feet elevation, La 
predominantly a tropical rain-forest, two thousand feet higher 
shows a marked increase in such temperate types as the oaks 
and chestnuts. The foliage is less luxuriant, and the climbers 
and epiphytes (except mosses and ferns), become decidedly 
less developed. In the upper zone mosses become extraordinarily 
abundant, great cushions of moss covering the ground and fallen 
logs, and the trunks and branches being covered and festooned 
with mosses of many kinds. They seem to find an especially 
congenial habitat in these cool wet forests, and are much more 
important than the liverworts which are so abundant in the 
lower elevations, although there are some species confined to 
the higher altitudes. 

At one point on the trail leading to the summit is an interest- 
ing illustration of the effect of increased temperature. This 
locality "Tjipanas, ' has a number of hot springs which issue 
from the mountain side and form a natural hot-house, where 
the vegetation has a genuine tropical luxuriance. Gorgeous 
orchids, pitcher plants, giant tree-ferns, and a dense drapery 
of ferns and mosses on the rocks, together presented a picture 
suggesting the hot zone 4,000 feet below. 

At this time (April) the young foliage of the evergreen foresl 
presented a great variety of beautiful tints, red, pink, yellow, 
adding much to the beauty of the scene. 

Toward the top of the mountain, the forest trees are low and 
distorted, with scanty foliage, the branches covered with moss 
and draped with long streamers of gray lichen. 1 The floor of 
this strange forest is covered with a carpet of dead leaves and 
twigs, among which a curious parasite with red and yellow 
flowers (Balanophora elongata), may sometimes be found, and 
with it a few ferns and a small terrestrial orchid an 
sociated. 

A very characteristic plant of this region is a tall yellow 

1 Schimper, loc. eit., p. 72li. gives the following aa the moat important tn 
Aralia sp., Myrsine avenis, Yaccinium floribundum. 



232 OUTLINE OF PLANT GEOGRAPHY 

primrose (Primula imperialis) not uncommon under the bushes, 
said to be confined to this mountain, and this is associated 
with a buttercup and raspberry, as well as several other common 
boreal genera. A very interesting plant is Nertera depressa, a 
little trailing plant growing at the base of the moss-covered trees. 
This same species is common in New Zealand and Australia and 
also occurs in temperate South America. 

Somewhat lower down there was a rich growth of liverworts, 
mosses and lichens, as well as some remarkably fine tree-ferns, 
(Cyathea sp.) forty feet or more in height. Several species of 
Gleichenia, including a large climbing species (G. arachnoides) 
were noted by the writer, and species of Lycopodium, including 
the cosmopolitan L. clavatum and L. complanatum, as well as 
the large climbing L. volubile and others. Some fine orchids 
were seen, the most notable a crimson Dendrobium and a large 
orange-flowered terrestrial species (Phajus?). 

The summit of Pangerango, the highest point of the Gedeh, 
is covered for the most part with scrub, but with open grassy 
patches between. The scrub is mostly a woody composite, 
Anaphalis Javanica, with whitish flowers, and associated with 
it are occasional low gnarled trees of Leptospermum floribundum. 
The latter belongs to the myrtle family, and the genus is espe- 
cially abundant in Australia. 

In general the summit vegetation of the Gedeh is distinctly 
boreal in type. Two fine rhododendrons, R. retusum and R. 
Javanicum, which at lower elevations are epiphytes, are here 
seen as terrestrial shrubs, and other members of the heath family, 
Vaccinium and Gaultheria, are abundant at the higher elevations. 
The latter is represented by two abundant species with white 
and black berries, having a strong wintergreen flavor, like their 
American relative, G. procumbens. 

East Java 1 

Eastern Java on the whole, is decidedly drier than the west, 
and this is reflected in the forest growth which is intermediate 
in character between the very wet western rain-forest, and the 
monsoon forest with a preponderance of deciduous vegetation. 

1 Schimper, loc. cit. 



THE PALAEOTROPICS 

There is greater variety in soil conditions than in west Java, 
and this results in a greater variety of forest trees. 

In parts of east Java are extensive teak forests, almosl pure 
stands of this important timber-tree. In the dry season the 
forest is quite leafless, and offers the strongest contrast to the 
exuberant luxuriance of the western rain-forest. There are 
some evergreen species associated with the teak, e. g., Albiz. 
stipulata, Butea frondosa, the latter, as in India, conspicuous 
for its showy red flowers. The deciduous forest is almost des- 
titute of epiphytes, but some species of Ficus occur which begin 
life as epiphytes upon the teak and other deciduous trees. 

A number of lianas, mostly Leguminosae, occur, and there 
is a rich growth of shrubs and small bushes, some with showy 
flowers like species of Cassia and Hibiscus. Palms and bam- 
boos are comparatively scarce. 

Where conditions permit an accumulation of humus, some 
of the rain-forest herbaceous plants, like the gingers (Curcuma, 
Amomum, etc.), and others with showy flowers, may be seen, 
and flowers in general are more noticeable than in the rain- 
forest, owing to the more abundant light. The display is great- 
est at the monsoon rains in November, before the new foliage 
appears on the deciduous trees. 

Krakatau 

A very instructive demonstration of the rapid development 
of vegetation under equatorial conditions is shown by the re- 
establishment of vegetation on the island of Krakatau which 
was blown up by the tremendous explosion of its volcanic crater 
in 1883. Life of all kinds was completely destroyed, and what 
was left of the island was buried deep in volcanic ashes. Kra- 
katau lies in the Straits of Sunda, midway between .Java and 

Sumatra. 

The first visit made to Krakatau after the catastrophe, was by 
Professor M. Treub, director of the Buitenzorg garden. This waa 
three years after the eruption, but by this time about a dozen 
species of ferns were well established, together with a considerable 
number of flowering plants. 

The writer 1 had an opportunity of visiting the island twenty 
i "The New Flora of Krakatau," American Naturalist, Vol. XLIII, August, 1909. 



234 OUTLINE OF PLANT GEOGRAPHY 

years later, in 1906, by which time the island was completely 
covered with dense vegetation in great variety. 

In places there was a broad beach with the characteristic strand 
plants. The ubiquitous Ipomoea pes-caprae, the curious grass, 
Spinifex, and a yellow leguminous vine (Vigna hitea), as well as 
several others, occupied the beach, while back of this was a belt 
of trees. Floating fruits of the Nipa-palm were stranded on the 
beach, but no swamp formation had developed. 

The most important tree of the belt above the beach was Ca- 
suarina equisetifolia, some at least 50 feet high, and a common 
member of the Malayan strand flora. Screw-pines and the hand- 
some Terminalia Catappa, with its symmetrical whorls of branches 
and big, shining leaves, were common, and the fine Barringtonia 
speciosa, with its big white flowers and square fruits. In short, 
the predominant strand plants were the same as in Borneo. The 
commonest climber was a vine (Vitis trifolia). A grove of coco- 
nuts had become established, and in full bearing, and the cool 
liquid contents of the nuts were hugely appreciated after a walk 
through the stifling heat of the tall grass jungle which covered 
much of the interior of the island. 

From Professor Treub's early study of the vegetation, it ap- 
peared that the first plants to establish themselves were certain 
very primitive blue-green algae, which prepared the way for ferns, 
which soon obtained a foothold, and were quickly followed by other 
plants, as soon as sufficient soil was developed. These first immi- 
grants were presumably derived from both Java and Sumatra, which 
are about equidistant from Krakatau. Some, like the coconuts 
and Barringtonia, evidently travelled by water, while the spores of 
the ferns, the minute seeds of orchids, and the fruits of grasses 
and Compositae, were probably wind-borne. Birds undoubtedly 
have played an important role in the introduction of many species. 

It is evident, both from the depth of the sea, and from the char- 
acter of both plants and animals, that in recent geological time 
the great Sunda Islands were part of the Asiatic continent. 

Extending eastward from Java is a chain of small islands, of 
which the last, and largest, is Timor. Between two of the islands 
nearest to Java, Bali and Lombok, is a narrow, but very deep 
strait, and Wallace l pointed out the fauna of the islands to the 

1 Wallace, A. R., The Malay Archipelago. 



THE PALAEOTROPK ■ 

east of this line was predominantly Australian. A study of the 
vegetation shows plainly that the floras of these eastern islands 
also show a distinctly Australian influence, although much 1< 
marked than the animal life. 

The subject has been investigated by later investigators, and 
a recent paper by Dr. E. D. Merrill l gives an admirable summary 
of the subject. Wallace's line is extended northward to the w< 
of the Philippines, Palawan being the only large island lying to 
the west. This line is supposed to mark the edge of the Asiatic 
continental shelf. A second line, Weber's line, running close to 
New Guinea and Australia, marks the edge of a second continental 
shelf upon which are situated Australia and New Guinea. The 
two continental masses are separated by an archipelago, of which 
Celebes is the largest member. 

There is a marked difference between the eastern and western 
Malaysian floras, although they have a very large number of 
forms in common. There are 356 Malaysian genera confined to 
western Malaysia, and 225 which do not occur west of Wallace's 

line. 

It is assumed that the two continental regions have been rela- 
tively stable, but the region between shows evidences of frequent 
elevations and depressions, with probable temporary connections 
with one or the other of the continental areas, thus permitting an 
occasional interchange of plants. This accounts for the presence 
of such distinctly Australian types as Eucalyptus, Casuarina, and 
Melaleuca, in the western part of Malaysia. 

The contrast between the floras of western and eastern Malaysia 
may be illustrated by the distribution of the essentially western 
Malaysian family, the Dipterocarpaceae. In the Sunda Islands, 
there are eleven genera and 144 species, while in the whole of the 
region east of Wallace's line, including the great islands of Celebes 
and New Guinea, there are but four genera and fourteen species, 
and possibly this number may be reduced as some of the recorded 
species are doubtful. 

The Molucca or Spice Islands, lying between Celebes and New 
Guinea, were formerly of great importance commercially, as the 
main source for such spices as pepper, cloves, nutmegs. The 

i "Distribution of the Dipterocarpaceae," PhUippii rnal of & VcL 

XXIII, No. 1., July, 1923. 



236 OUTLINE OF PLANT GEOGRAPHY 

cultivation of these spices in the islands has greatly decreased in 
late years, and the trade in these products is no longer of very 
great importance. 

The Philippines 

Of special interest to Americans is the Philippine Archipelago, 
lying North of Borneo and Celebes, and extending nearly to lati- 
tude 20°. 

The Philippines share many species with the Sunda Islands, 
and their flora is predominantly Malayan in character; but in 
the northern island, Luzon, especially in the mountains, is a pro- 
nounced infusion of temperate species, related to those of the 
Asiatic mainland, especially China. 

The botany of the Philippines has been the subject of much 
investigation since the American occupation, so that our knowledge 
of the very extensive flora has been greatly increased. It must be 
said, however, that much important work was also done during 
the Spanish regime. 

Like Java and western Sumatra, the Philippines are character- 
ized by extensive volcanic formations, and the vegetation on the 
volcanic peaks has much in common with the similar mountain 
floras of the Sunda Islands. 

The shore vegetation does not differ essentially from that al- 
ready described for other Malayan coasts, and includes mangrove 
and Nipa swamps, and beaches with the same strand species. 
Near Manila a screw-pine (Pandanus tectorius) is abundant, and 
its leaves are used for many purposes by the natives. Calophyl- 
lum, with beautiful glossy leaves, Terminalia, Barringtonia and 
Casuarina, are the same as in Borneo, and elsewhere in Malaya, 
and the trailing morning glory (Ipomoea pes-caprae), grows every- 
where along the beach. An interesting little water-fern (Marsilea 
crenata), was also noted by the writer, in low ground near the 
shore. 

The writer had an opportunity of studying the vegetation on 
two of the volcanic mountains in the vicinity of Manila, Mt. 
Maquiling and Mt. Banajao. 

The former is about 3,500 feet altitude and its vegetation has 
been very little interfered with. The forest at the lower elevations 
has several species of Dipterocarps, which, as elsewhere, are the 



THE PALAEOTROPICS 



2:37 



most valuable of the timber-trees, as well as among the largest. 
Figs of several species are abundant, and of other common trees, 
the following may be mentioned: several oaks (Quercus Luzonen- 
sis and others), are common, especially at the higher elevations 
and various species of Celtis, Trema, Artocarpus, Myristica (nut- 
meg), Cinnamomum, Pithecolobium, Pterocarpus, and many 
others. 

At about 1,000 feet the vegetation is particularly luxuriant, and 
many ferns and palms are conspicuous. Among the latter are 




Fig. 65. — Lowland rain-forest, Luzon, P. I. Photo., Dr. E. B. Copeland. 



numerous rattans, as well as some very beautiful species of Onco- 
sperma and Areca, with slender trunks and graceful feathery 
foliage. The sugar-palm (Arenga saccharifera) , with its immense 
leaves, also occurs in this forest. A fine fan-palm (Livistona sp.) 
is also common. The usual profusion of lianas and epiphytes, 
characteristic of the rain-forest, is present. Two especially showy 
lianas, both Leguminosae, were noted, species of Bauhinia and 
Strongylodon, the latter with flowers of a peculiar blue-green 

color. 

Ferns are very abundant, and there are many liverworts and 
mosses on the trunks of the trees and on banks and fallen 1« >u;s. 

Of the herbaceous plants the most conspicuous was a huge 



2:>s 



OUTLINE OF PLANT GEOGRAPHY 



arum {Ahoasia sp.) with immense leaves six or seven feet long. 
A single specimen of a curious parasite, Rafflesia sp., was seen. 

Some handsome orchids {Phajus sp., Vanilla sp.), bright scarlet 
Aeschynanthus, showy pink epiphytic Medinilla and Begonias, 

. e dashes of bright color to the prevailing green of the luxuriant 

foliage. 

Near the summit of the mountain, some pitcher plants were 
seen, and also fine filmy ferns and tree-ferns. 




Fig. 66. — Mountain forest, Luzon, P. I. Photo., Dr. E. B. Copeland. 



Banajao is about twice the height of Maquiling, but the lower 
part has little forest remaining; and up to about 3,000 feet is to a 
great extent covered with the coarse "lalang" grass. The forest 
is less luxuriant than on Maquiling, with fewer palms, except 
rattans. At the higher elevation, up to the summit (7,500 ft.), 
the forest is predominantly coniferous, but the trees are all of 
the yew family, species of Dacrydium, Taxus, and Podocarpus. 
The liverwort flora is a very rich and interesting one, including 
a number of species collected by the writer in Java and Sumatra. 
A rather unexpected find was a peat-moss (Sphagnum), in fine 
fruit. 

No showy orchids were seen on Banajao, but some other very 
beautiful epiphytes were common. Especially striking were some 



THE PALAKOTROPK S 



239 



magnificent Begonias and Medinillas. The latter an- very 

abundant in the Philippines, and the large drooping infloi 
cences, the flowers surrounded by big pink bracts, air extremely 
showy. 

The northern part of Luzon is a rugged mass of mountains, with 
a rich and varied flora. At about 3,000 feet are encountered true 
pines (Pinus insular is), which at Baguio (5,000 ft.) form an ex- 
tensive open forest, such as one is familiar with in the north tem- 




A B 

Fig. 67. — A. Pines (Pinus insularis), Baguio, P. I.; B. Orchid (Cypripcdium 
Argus), and fern (Gleichenia sp.); high mountains, Northern Luzon. Photo., 
Dr. E. B. Copeland. 

perate regions, and not at all suggestive of the tropics. Th< 
pines are found up to nearly 8,000 feet in the drier soils, but for 
the most part the higher forest is a dense mossy jungle, composed 
of oaks, myrtles (Eugenia 8pp.), and Podocarpus. The I 
draped in a profusion of mo-- 3, liverwort- ami lichens in gn 
variety. Tree-ferns, and many others abound, and in general the 
vegetation is much like that of the higher mountains of western 
Java. 



240 OUTLINE OF PLANT GEOGRAPHY 

A few pitcher plants were noted, but the most striking feature 
of this high mountain region was the abundance of beautiful 
flowers, which at the time of the writer's visit, the end of May, were 
in their fullest bloom. Many remarkably handsome orchids were 
abundant, including several species of Dendrobium, Coelogyne, and 
Cypripedium. The beautiful Philippine lily (Lilium Philip- 
pic use), displayed its big white trumpets by hundreds, and great 
bushes of azalea and rhododendron were covered with white and 
red flowers, while thickets of pink Begonias as high as one's head, 
grew in profusion. Pink Medinillas hung from the branches 
of the trees, and on the ground were many familiar looking, but 
less showy things. Several species of raspberries, strawberry, 
violet, buttercups, a large white anemone, lobelia, and everlasting 
(Gnaphalium) recalled the summit of the Gedeh in Java, and one 
noted also the white-fruited wintergreen (Gaultheria), and species 
of Vaccinium, like those of the Gedeh. Other northern types were 
an elder, and a dwarf chestnut (Castanopsis), the latter having 
a representative in the Pacific forest of North America. 

Peppers, myrtles (Eugenia spp.) and Begonias, as well as the 
orchids and pitcher plants are more reminiscent of the tropical 
forests of the lower elevations. A member of the Magnolia family, 
Drimys piperita, is interesting as the genus is also characteristic 
of New Zealand and temperate South America. 

Club-mosses, species of Lycopodium, both terrestrial and 
epiphytic, are abundant, and the species are the same as on the 
Gedeh in Java, and include the wide-spread boreal species, L. 
clavatum and L. complanatum. 

The Philippines, lying to the east of Wallace's line, combine 
in their flora elements derived on the one hand from the great 
Sunda Islands, and on the other from eastern Malaya and Aus- 
tralia. 1 Thus of the 356 genera peculiar to western Malaya, the 
Philippines possess 61%, while of the 225 genera of eastern Malaya, 
absent from the region west of Wallace's line, the Philippines show 
25%. It is evident then, that the relationships are much more 
intimate between the flora of the Philippines, and that of the 
Sunda Islands, than with the more scattered islands to the south 
and east through which the eastern Malayan and Australian 
elements have presumably migrated into the Philippines. 

1 Merrill, loc. cit. 



THE PALAEOTROPK 241 

The occurence in northern Luzon of such boreal types as pin 
oaks, buttercups, lilies, etc., indicates some former connection with 
the Asiatic mainland. It is unlikely that these entered Luzon 
via Formosa. The deep water separating the two islands implies 
a long period of separation, and this is clearly indicated by the 
very different floras, Formosa having a flora closely related to that 
of China. 

Austro-Malaya 

The great island of New Guinea or Papua, 1,500 miles long, and 
with an area of over 300,000 square miles, is the largest island in the 
Pacific, and with its adjacent small islands is the easternmost 
member of the Malay Archipelago. The flora is still very in- 
completely known, but it is evident that while it is predominantly 
Malayan in character, there is a large infusion of true Australian 
types. 

The lofty mountain range forming the backbone of the island 
has the highest peaks of the whole Pacific area, except continental 
America, some of these being over 15,000 feet elevation. The 
great range of conditions, between the hot coastal plains and the 
highest summits where in places permanent snow is found, results 
in an extraordinarily extensive and varied flora. In most parts 
of Papua the rainfall is heavy, especially in the western part, but 
there are much drier sections in the south and east. 

David 1 states that Papua is part of the great "Himalayan- 
Burman arc, prolonged through the Malay Peninsula, Sumatra. 
Java and Timor." This relation to the Indo-Malayan region is 
clearly indicated by the character of the vegetation which in its 
main features is essentially Malayan, with an intermixture in the 
cooler mountain districts of northern genera like the oaks and 
rhododendrons so characteristic of the Himalayan flora, as well as 
many northern herbaceous genera. While a majority of the genera, 
and a good many species are identical with those of the western 
Malayan region, there is a very large proportion of endemic 
genera and species, and the flora is a very distinct one. a 

The greater part of Papua is heavily forested except where 
lalang grass has invaded cut-over or burned forest land. The for 

1 David, T. W. E., Federal Handbook for Australia, p. 320, Melbourne, 1014. 

2 Maiden, J. H., Federal Handbook for Australia, p. 179. 




Plate XXL— Tropical jungle, North Queensland, Australia. Center, tree-ferns 
(Alsophila Australis (?); at right and in foreground, rattans (Calamus sp.). 



242 



THE PALAEOTROPIO 243 

trees are in general the same types as in western Malaya, but 
the Dipterocarps are very much less developed, while in the drier 
regions of the south coast, the vegetation is decidedly Australian. 
Here there are open savannas, with coarse gras- s 3 e. g., Imperata 
arundinacea, Anthisteria, Andropogon, Pennisetum, etc., while 
the trees and shrubs are for the most part the same as those on the 
Australian mainland. Such distinctly Australian genera as Eu- 
calyptus, Acacia, and various Proteaceae, comprise most of the 
trees and shrubs of this savanna flora. 

This region is separated from the York Peninsula, the noil hern- 
most extension of Australia by less than 110 miles of water, and 
the very shallow sea which now separates Papua and Australia. 
as well as the great similarity in the animal life, indicates that the 
separation of the two regions is of comparatively recent date. 

North Australia 

Northern Australia lies well within the tropics and North 
Queensland has a genuine tropical flora, largely of Malayan 
origin. The northeast coast, which has a heavy rainfall, was 
visited by the writer in July, 1921. 

The neighborhood of Cairns, the principal port, is flat and 
sandy, with a mixture of Australian and Malayan types, Euca- 
lyptus trees being associated with species of Ficus, Pandanus. 
and other Malayan types. Where streams enter the sea, there 
is a mangrove formation of the same sort as that in the Malay 
Archipelago. 

South of Cairns lies the Bellenden-Ker range, the highest 
mountains in Queensland, and in this neighborhood is the wettest 
district in Australia. From a few days sojourn at Babinda, 
which has an average yearly rainfall of 150 inches, the writer 
can vouch for the heavy precipitation of this region. The forest 
in the neighborhood of Babinda is a genuine rain-forest, much 
like the lowland forests of Java or Borneo in general appear- 
ance, except that the trees are not so large. This jungle is often 
quite impenetrable, the trees loaded down with lianas and 
epiphytes of various kinds, among them several species <>t' rat- 
tans, which were only too much in evidence. Throughout the 
Malayan region, these are the greatest hindrance to travel in 



244 



OUTLINE OF PLANT GEOGRAPHY 



the forest, their tough spiny stems, and leaves armed with re- 
curved thorns, making absolutely impassable barriers, veritable 
barbed-wire entanglements. Climbing aroids, e. g., Pothos 
longipes, Rhapidophora Australasica, are much in evidence, 
as well as many other lianas, among which are several species 
of Vitis, and a pepper {Piper Mestoni) the latter with very showy 




Fig. 68. — Mangroves, Cairns, North Queensland, Australia. 

mangroves. 



At right, young 



scarlet fruits. The usual abundance of epiphytes, orchids, ferns, 
Peperomia, etc., was noted. 

Ferns, liverworts, mosses, were not remarkably abundant. 
Of the ferns, the most striking were some gigantic specimens 
of Angiopteris. 

Palms are a conspicuous feature of the Queensland rain-forest. 
The commonest and most beautiful are the species of Archonto- 
phoenix, whose straight slender stems, and crowns of graceful 
feathery leaves, are among the most beautiful of the order. A. 
Cunninghamiana is often cultivated under the name Seaforthia 




Plate XXII. — Grove of Archonto phoenix Alexandrite, North Queensland. 

245 



246 



OUTLINE OF PLANT GEOGRAPHY 



elegans. Two other palms were seen near Babinda, a curious 
fan-palm (Licnala Muelleri) and the pretty " walking-stick " 
palm, Bacularia sp. 

Further north, in the York Peninsula, are several Indo-Malayan 
genera, Caryota, Borassus, Areca, and others, which were not 
seen in the Cairns district. Pitcher-plants of several species, 
have also been described from the York Peninsula. 




A B 

Fig. 69. — Rain-forest, North Queensland, Australia. 

A. Young palms (Archontophoenix sp.). 

B. Edge of jungle, showing rattans and screw-pine. 



Back of the coast, at an elevation of 2,000 to 4,000 ft. is a 
plateau which supports a fine forest, mostly of hard-woods, of great 
value as timber. These forests are rapidly disappearing before the 
inroads of the lumberman, but there are still accessible remnants 
of the forest which show their character. This forest is developed 
only on the rich basaltic and alluvial soils, the poorer sandy soils 
being occupied by open forests of gums, as elsewhere in Australia. 







Plate XXIII. — Hard-wood forest, table-land North Queensland. 

the center is a "cedar" (Cedreal toona). 



The tree in 



247 



IMS 



OUTLINE OF PLANT GEOGRAPHY 



The upland forest has fewer lianas and less dense undergrowth 
than the coastal rain-forest, but the trees are much finer, being 
wry tall with straight clear trunks, sometimes of great size, 
5 to 10 feel in diameter in the case of the Kauri (Agathis Pal- 
merstoni) and the " red-cedar" (Cedrela toona). Trees known 
locally as "beech," "maple," "hickory," etc., are not even 
remotely related to their northern namesakes. They are mostly 







*MT 



\f' v 



""^^pe^ 







Fig. 70. — A. Staghorn fern (Platycerium grande,) botanical garden, Brisbane. 
B. Giant fig (Ficus sp.), North Queensland. 

species of Flindersia, a genus usually placed in the mahogany 
family (Meliaceae). Many of the large trees have extensive 
buttresses at the base, a very common feature in the larger 
trees of tropical forests. 

In the Queensland "scrubs," the local name for the rain-for- 
est, are a number of fine trees belonging to the peculiar family 
Proteaceae, developed to an extraordinary degree throughout 
Australia. One of these, Grevillea robusta, is not uncommon 
in cultivation in California. Other genera are Embothrium 
and Stenocarpus. 



THE PALAEOTROPICS 249 

Other characteristic trees are species of Elaeocarpus (Tiliacea 
Sideroxylon (Sapotaceae), Eugenia and the wide-spread Aleuritet 
Moluccana, the "Kukui" of Hawaii. Two species of Podocarpus 
also are found. 

The giants of this region are banyan figs which attain a pro- 
digious size. Like so many species of Ficus, these giant Queens- 
land figs begin life as epiphytes, and their huge trunks are formed 
by the coalescence of many aerial roots. The trunk of one of 
these, seen by the writer, was said to be 120 feet in circumference, 
and the spreading crown was in proportion. 

A dreaded pest of these forests is the tree-nettle (Laportea 
moroides), a rank weed some ten or fifteen feet high, whose 
touch is agony. Another species, L. gigas, is a tree of large 
size. 

Screw-pines abound in north Queensland, and there are sev- 
eral species of cycads. The genus Macrozamia is wide-spread 
in Australia, occurring in every state; but Cycas and Bowenia 
are confined to tropical Queensland, and the latter genus is 
exclusively Australian. Bowenia differs much in appearance 
from the other cycads, having a bipinnate leaf which in form 
suggests a fern. 

Polynesia 

Occupying the whole central area of the Pacific, from Fiji, 
Samoa, and Tahiti on the south, to Hawaii on the north, are 
the innumerable islands of Polynesia, all lying within the tropics 
and enjoying a tropical climate modified by the cooling trade 
winds of the great ocean. 

Except for Hawaii, the flora of the Polynesian regions is still 
quite imperfectly known; but in spite of the small size of the 
islands, and the great isolation of many of them, the floras have 
much in common, and on the whole may be considered as pre- 
dominantly Malayan in type. There is also a strong infusion 
of Australasian elements. 

Many of the Polynesian islands are low coral formations ris- 
ing only a few feet above sea-level, but others like Tahiti, the 
Samoan Islands and the Hawaiian Archipelago, are volcanic 
masses, forming rugged mountains, which in Hawaii reach an 
altitude of over 13,000 feet. These highest mountains are 



250 



OUTLINE OF PLANT GEOGRAPHY 



recent volcanic cones, and in Samoa and Hawaii there are still 
active craters. 




Fig. 71. — Forest interior, Samoa. Photo., Mrs. D. S. Jordan. 

The low coral islands are evidently recent formations, and 
incapable of supporting any but a scanty flora which has pre- 
sumably reached them from outside in recent times. 




6 






X 



3 






251 



2.VJ 



OUTLINE OF PLANT GEOGRAPHY 




Fig. 72.— Hawaiian rain-forest. At back, "ohia" (Metrosideros polymorpha) ; 
in center, lobelia (Cyanea coriacea). Photo., Dr. J. F. Rock. 

The case of the large volcanic islands is very different, as the 
recent volcanic deposits are probably superimposed upon more 



THE PALAEOTROPICS 253 

ancient sedimentary rocks, the remains of some much larger sub- 
merged land-masses. Indeed there is much reason to suppose 
that all of Polynesia represents the remnants of extensive con- 
tinental, or sub-continental masses once connected with the Ma- 
layan region. 

The flora of the southern larger islands has much in common with 
that of the Malay Archipelago and there are many identical 
species, as well as endemic species belonging to wide-spread 
Malayan genera. There is also a marked Australasian element 
in the floras of Polynesia. 

Of course one must distinguish between the plants which man 
has carried with him all over the tropics, and those which are 
truly indigenous. The coconut, bread-fruit, bananas, sugar 
cane, etc., are universal in tropical countries. But leaving these 
aside, there is no question of the close relationships existing be- 
tween the southern islands of Polynesia and those of the Malay 
Archipelago. 

The traveller between San Francisco and Australia or New 
Zealand, can get a glimpse of the Polynesian vegetation, as the 
ship stops in Hawaii, Samoa, Fiji, or Tahiti. A short sojourn in 
any of these islands will suffice to give one an idea of the general 
character of the vegetation, which has much in common through- 
out Polynesia. 

Along the shore in Tahiti one sees the yellow Hibiscus, the 
"Hau" of the Hawaiians, screw-pines, and the handsome Bar- 
ringtonia, so characteristic of the Malayan strand vegetation, 
while the forest trees, as well as the rich undergrowth of herba- 
ceous plants, recall the rain-forests of the Malayan regions. This 
is especially true of the very abundant ferns, club-mosses and 
liverworts, many of which are wide-spread Malayan species. 
Among the ferns, giant specimens of Angiopteris are especially 
conspicuous, and there are a good many orchids, also belonging 
to Malayan genera. In Tahiti, the only orchid cultivated for 
commercial purposes, Vanilla, is a crop of considerable impor- 
tance. Climbing plants are much less developed in the Polynesian 
forests than is usual in the Malayan rain-forest . 




Plate XXV. — Forest interior, Samoa. Photo., courtesy of Dr. D. S. Jordan. 



254 



THE PALAEOTROPICS 255 



Hawaii 



At the extreme northern limit of Polynesia lie the remote Hawai- 
ian Islands, separated from the nearest land of any extent, by over 
2,000 miles. In spite of their great distance from the islands to the 
south, the general character of the flora is much the same, and 
Malayan types are dominant as they are throughout Polynesia. 
Nevertheless it is evident that the islands have been isolated for 
a very long time, and in consequence the great majority of the 
species, and a good many genera, are restricted to the Hawaiian 
Archipelago. Hardly any part of the world has so large a propor- 
tion of endemic species, upwards of 75% of the ferns and flowering 
plants being unknown outside these islands. 

North America is the nearest continental land to Hawaii, being a 
little more than 2,000 miles distant; but the floras of the two have 
very little in common, in spite of the fact that the usually accepted 
agents in distribution, viz., ocean currents, winds and migratory 
birds, are all active between western America and Hawaii. 

That the Hawaiian islands have been isolated for a very long 
period is amply proven by the peculiarities of both the animal and 
plant inhabitants whose nearest relatives, however, are for the 
most part found in the Malaysian and Australasian regions, and 
not in America. 1 

The Hawaiian Archipelago consists of several large islands, with 
a total area of nearly 6,500 square miles, lying between 18° 22' 
and 21° 15' north latitude. From the main group a long series of 
reefs and small islets extends for about eighteen degrees to the 

northwest. 

There is ample evidence that the large islands were formerly 
united into a single land-mass which through gradual subsidence 
has become separated into the islands as they now exist. The 
northernmost island, Kauai, was the first to be cut off, as is indi- 
cated by the broad and deep channel between it and its neigh- 
bor to the south, Oahu. The long period of isolation of Kauai 
is also indicated by the greater degree of endemism in the flora. 

The topography of the islands, especially the older ones, is 
excessively rugged. The prevailing northeast trades bring torren- 

1 Campbell, D. H., The Derivation of the Flora of Hawaii, Leland Stanford Junior 
Publications, 1919. 




Plate XXVI.— Lower forest, Hawaii. The light patches are "Kukui" (Aleurites 

Moluccana). 



256 



THE PALAEOTROPICS 257 

tial rains to the windward side of the islands, while the lee sides 
may be very dry. Where the mountains are low, as in Oahu, the 
rain may pass over the crest and fall at the head of the valleys on 
the lee side. An annual rainfall of 500 inches has been recorded 
from a station in Kauai. 

The lowlands are closely cultivated, sugar and pineapples being 
grown on a very large scale, as well as the usual tropical fruits; 
and in some localities rice is grown. 

Most of the vegetation seen about Honolulu and the other towns 
is exotic, and a great variety of beautiful flowering trees and shrubs 
is cultivated. The two commonest trees, the "algaroba" (Proso- 
pis sp.) and " iron-wood (Casuarina equiseti folia) , are both in- 
troduced, but have become completely naturalized. 

The strand-vegetation includes such wide-spread types as 
Hibiscus tiliaceus, Ipomoea pes-caprae, Scaevola, Pandanus, 
Calophyllum — all familiar strand-plants of the eastern tropics; 
but the strand-flora as a whole is not an extensive one. 

The commonest trees of the lowland forest, where it has sur- 
vived, are two — the "Kukri" or "candle-nut" (Aleurites Moluc- 
cana), and the "mountain-apple" (Eugenia Malaccensis). As both 
of these are wide-spread in Malaysia and are of considerable eco- 
nomic value, it is thought that they may have been introduced 
by the early immigrants from the South Seas. 

The upper forest zone, on the windward side of the islands, is 
a pronounced rain-forest with dense growth and many epiphytes; 
but lianas are not abundant, the most important being a climbing 
screw-pine, Freycinetia Arnotti. The most abundant tree of the 
upland forest is Metrosideros polymorpha, a near relative of the 
New Zealand rata. The showy red flowers are a great attrac- 
tion to the honey-sucking birds of the peculiar Hawaiian family 
Drepaninidae. Another important tree is the "Koa" (Acacia 
Koa), much resembling some of the Australian species. 

The trees and shrubs of the lower forest zone are largely genera 
common to the eastern tropics and Australia, but absent from 
America. Among these may be mentioned Pittosporum, ( lardenia, 
Coprosma, Metrosideros, Santalum, Dracaena. The ferns and 
liverworts show a remarkable number of species identical or closely 
related to those of the Malayan-Australasian area. 

There are a good many endemic Hawaiian genera, e. g., Platy- 



258 



OUTLINE OF PLANT GEOGRAPHY 



desma (Rutaceae), Gouldia (Rubiaceae), Raillardia (Compositae), 
Cyanea (Lobeliaceae). The latter family is especially interesting 
from the standpoint of evolution. It is developed to a remark- 
able degree in the Archipelago, the greatest number of species, 
as well as the most specialized ones, occurring in Kauai, the 
oldest island — the number of species being much less in the 
more recently isolated islands, Maui and Hawaii, although these 
islands are very much larger than Kauai. 










Fig. 73. — Gunnera petaloidea, characteristic of the wet mountain forests of Hawaii. 
Note the man at right of center. Photo., Dr. J. F. Rock. 



There is but a single native genus of palms, Pritchardia, while 
there are no gymnosperms; and some wide-spread tropical genera, 
especially Ficus, are also entirely absent. The cosmopolitan family 
Araceae has no certainly indigenous representatives, although 
the staple food-plant of the natives, the "taro" (Colocasia anti- 
quorum), is an aroid. Orchids, so abundant in most tropical 
countries, have only three species. One of the most conspicuous 
denizens of the upper wettest rain-forest is Gunnera petaloidea, 
with great rhubarb-like leaves four to five feet across. This much 
resembles the species from Chile. 







259 



260 



OUTLINE OF PLANT GEOGRAPHY 




Aa in all volcanic islands, ferns play an important role in the 
vegetation of the mountain forests, and this is notably the casein 
Hawaii. As has already been mentioned in regard to the restora- 
tion of the vegetation of Krakatau, after the great eruption, so 
in Hawaii, ferns are among the pioneers on the new lava dis- 
charged from the active craters. 

Doubtless one of the important factors determining the pecu- 
liarities of these volcanic is- 
land floras, is the preponder- 
ance of volcanic soils which 
are not always suited to 
plants from outside. Thus 
in Hawaii it has been ob- 
served that only the strictly 
indigenous species seem able 
to get a foot-hold on the new 
lava. 

It has been very commonly 
held that these isolated vol- 
canic islands have always 
been completely separated 
from any larger body of land, 
and that the vegetation has 
been introduced from outside 
since the first appearance of 
the islands. There are very 
serious objections to this view, 
the greatest being the over- 
whelming preponderance of 
plants of Malayan and Aus- 
tralasian affinities, although 
very many of these are quite unfitted for natural transporta- 
tion from these remote regions by any agency that is com- 
prehensible. On the other hand, the number of strictly American 
types is very small, and can mostly be explained as introduced 
into the islands by currents, wind, or by birds, of which there are 
many regularly migrating between the American mainland and 
the islands. 

The palms, screw-pines, acacias, and most of the indigenous 



Fig. 74. — Tree-lobelia (Delissea longifolia) 
Photo., Dr. J. F. Rock. 



THE PALAEOTROPICS 261 

trees and shrubs, are unmistakably of South Pacific origin, and 
the same is true of many delicate plants of the wet mountain- 
forests, whose seeds could hardly survive an ocean voyage of 
several thousand miles, and then find their way to the cool moun- 
tain forests where alone they can grow. 



CHAPTER VIII 
THE NEOTROPICAL REGIONS 

The distribution of the tropical vegetation of the new world 
is very different from that in the eastern hemisphere. The whole 
tropical region from northern Mexico to Argentina and Chile 
is continuous, and traversed by the great western mountain range 
of the Cordillera; and there is nothing comparable to the great 
expanses of desert separating the African wet tropics from the 
Indo-Malayan regions. This condition results in a much more 
homogeneous vegetation than is found in the Palaeotropics, 
although there is an exceedingly rich and varied flora. 

The great Cordillera traversing western America from Alaska 
to Patagonia is a factor of the first importance in the distribution 
of plants in western America, both within and outside the tropics. 
This great mountain system has served as a highway for the migra- 
tion of many plants, both north and south, and the influence of 
this great mountain barrier on both rainfall and temperature is 
very great, and is a controlling factor in the character of the vegeta- 
tion within its influence. 

The area of land within the equatorial belt is very much greater 
in America than in either Asia or Africa. While in the old world 
the northern tropics are largely deserts, like the Sahara, Arabia 
and northwest India, in corresponding latitudes in America the 
land areas are of relatively limited extent, and where deserts exist, 
they are insignificant compared with the great deserts of tropical 
Asia and Africa. 

The equator crosses the broadest part of South America, through 
the immense Amazon valley, with its net-work of great rivers; 
and this whole region is occupied by the greatest continuous extent 
of tropical forest in the world. This immense region, extending 
from the Atlantic to the Andes is quite unequalled for the extent 
of its equatorial forests, which for variety and luxuriance can only 
be matched by the much less extensive forests of the equatorial 
forest belt in West Africa and the Malayan regions. 

262 



THE NEOTROPICAL REGIONS 



263 



The American tropics, except for the West Indies and Galapagos 
Islands, constitute a single continental area. 

Mexico 

The northern part of Mexico, both geographically and biologic- 
ally, is part of the region which includes much of the states of 
Texas, New Mexico, Arizona and California. 

The southern plateau region of the United States is continued 
southward into Mexico, where it becomes much higher, reaching 




Fig. 75. — Sub-tropical vegetation, Mexico. Branches covered with epiphytes, 
largely Bromeliads. Photo., Mr. G. N. Collins. 

7,000 feet in the vicinity of Mexico City. The greater part of 
Mexico is occupied by this central plateau, to the west of which 
the mountains form a continuation of the California Sierra. Part 
of this system forms the central range of the long peninsula of 
Lower California. The plateau of the Mexican mainland is sepa- 
rated from the Gulf of California by a high mountain range, which 
extends southward along the whole coastal region which forms a 
narrow strip between the mountains and the Bea. Eastward the 
plateau descends more gradually to the Gulf of Mexico. 

Much of Mexico is volcanic, and the great volcanic cones, one 



'2i\ I 



01 ri i\i OK PI w l' 01 OOH M'H> 



,,, ^hich, Oriiaba, ovej 18,000 feet elevation, ia the highest peak 

,„ \,„il, \ni.ii, itli of Ul SKA, Mir Important faCtOl - in phut 

distribution 

With such great range In elevation, and also great difference* oi 
rainfall, it li not remarkable that the Mexican flora la a verj 
cvini -n .- one 

Northern Mexico, In common with the southern plateau region 
of the United States, has a scanty rainfall, and a vegetation de 



" JEP" -^aa^EpsaaWa^P 

jajaflayaX & jf&^. 








aB&*sL 




aftU! 








-* H 




*vfl 




^J||f 


:*g 


^MK& 




ja^ - Ji3^ '* % 

rf ^K - <&|r wg 


i 


I 











cidedl^ \ rophyi in ch t. in which Cacti form a conspicuous 

in northwest Nfexieo and low,-- California true desert 

\ il over much of th ntry, but southward there 

an u* - v in • ad bel he [topic of Cancel 1 

n bundant summer he country, and 

much more luxuriant than further north, 

R<w owing the plateau, the climate of 

v \ well within the tn is temperate 

.1. 



THE NEOTROPICAL REGIONS 

Travelling southward over the Mexican table land, one is at 

once impressed by the great number and variety of the Cacti, 
which here attain their maximum development, -nine of them 
being candelabra-like trees 40-50 feet high. With these are asso- 
ciated various other xerophytes, notably the century plants {Agave 
spp.), Yuccas and other characteristic American desert tyjx 

With the diminishing breadth of Mexico toward the south, 
the plateau becomes restricted, and is broken by numerous hills, 
and in places by swampy areas and lakes, as in the vicinity of 
Mexico City, so that the flora is much more diversified than in 
the northern plateau. The climate of this region is mild, with a 
dry winter and rainy summer, much like that of parts of South 
Africa. 

The Valley of Mexico for centuries has been the seat of a large 
population, and is to a great extent under cultivation, or supports 
herds of cattle. Remains of extensive irrigation and drainage 
works show that formerly an even greater area was under culti- 
vation than at present. 

While much of the drier parts of the plateau are covered with 
Cacti, Agaves, mesquit, and other xerophytes, there are moist 
canyons and open valleys where vegetation is more luxuriant, and 
the remains of forest at Amecameca, and some other hills, indicate 
that much of the open count ry was once covered with forest. 

About Mexico City are extensive fields and gardens where corn, 
wheat, and the usual vegetables, fruits and flowers of the region 
are grown. In the summer, the markets show quant it ies of oranges, 
mangoes, avocadoes, strawberries and the fruits of certain Cacti. 
Some of these, like the mangoes, probably are brought from the 
lower country "Tierra caliente." 

The great plantations of centuiy plants, "maguey" in the 
vernacular, are a feature of the environs of Mexico City. The 
national drink, "pulque," is the fermented sap obtained by cutting 
out the great flower-stalk, just before it begins to elongate. The 
sap collects in the cavity left, and is gathered from day to day as 
long as it continues to flow. Enormous quantities of pulque arc 
shipped to the capital daily. From other species of Agave a 
potent liquor "mescal' is distilled, and several species yield 
fibres of great strength. Sisal hemp is the product <»!' .1. rigida 
var. SisiUuid. 



266 OUTLINE OF PLANT GEOGRAPHY 

The forests of this region are made up mostly of trees of boreal 
genera. Oaks in gnat variety, both evergreen and deciduous, are 
especially abundant in these mountain forests, and several species 
of pines and firs, a juniper and elder, are reminiscent of the forests 
of Arizona and California. A species of Arbutus, much like the 
California!! madrono is also found in the Mexican highlands. 

With the evergreen oaks, pines, and firs, there are deciduous 
trees closely related to those of the temperate United States, such 





Xerophvtic vegetation, South Mexico, State of Michoacan. 
Euphorbia (E. fuka). Photo., Mr. G. X. Collins. 



Cacti, 



as walnuts, sycamores, ashes and poplars, much like species found 
in California and Arizona. 

Above the forest zone, on the higher mountains, the shrubs and 
herbaceous plants are almost exclusively of northern types, grasses 
and sedges, a great development of Compositae (Baccharis, Eupa- 
torium, etc.), Ericaceae, Rosaceae, Umbelliferae and Cruciferae. 

The railway to the coast from Mexico to Vera Cruz passes 
through the sub-tropical zone, "Tierra templada," into the tropical 
zone, "Tierra caliente" reaching some 3,000 feet above the coast. 

As one descends, the oaks, pines, and other boreal genera be- 
come mingled with trees of more tropical aspect, such as members 
of the myrtle and custard-apple families, laurels, and especially 








t ■ <-» 



Plate XXVIII.— Sonoran desert vegetation, Punto Kin-., Western Mexico. At 
left, /dria columnaria. Photo., Dr. W. S. ('<><>/>< r. 



2G7 



268 



OUTLINE OF PLANT GEOGRAPHY 



the distinctly American family Malpighiaceae. Bamboos, small 
palms, tree-ferns, lianas and epiphytes become more and more 
abundant as t be tropical zone is approached. Among the epiphytes 
are some true parasites of the mistletoe family, (Loranthus, Pho- 
radendron), and the exclusively American family Bromeliaceae 
is represented by a great number of species. This family is repre- 
sent ed in our Gulf States by the "Spanish moss," and others, 



'~W 




^^^^# 



« 



* ' .*&* HIS 

mm 




tw^l - ■-■+* 




Fig. 78. — Coastal desert. Shore of Gulf of California at Libertad, Sonora; Frank- 
enia Palmeri, dominant. Photo., Dr. W-. S. Cooper. 



especially in Florida. Orchids are also extremely abundant in 
this region, and include some very beautiful species. 

The region between 1,000 and 2,000 metres * has a heavy rainfall 
pretty evenly distributed. It is a region of evergreen oaks, and 
tree-ferns, and has many epiphytic orchids, and some small palms, 
(Chamaedoria spp.). This region has more species than the 
tropical belt below it. 

The immediate coastal area is not so luxuriant in its vegetation 
as the region above 500 feet, as parts of it are quite barren, and 
only in the low ground and along the streams, is a true forest 

1 Drude, loc. cit., p. 507. 



THE NEOTROPICAL REGIONS 



269 



developed. In the zone between 500-1,000 metres, a true tropic-i I 
rain-forest is found. This zone is rich in palms (Acrocomia, Sabal, 




Hi 



m 



to 



Fig. 79. — Tree cactus (Pachyccreus Pringlei), near Libertad, Mexico. Photo., 

Dr. W. S. Cooper. 



Oreodoxa, etc.), and among the characteristic forest trees are 
giant silk-cottons (Bombax), laurels, Terebinthaceae, Combreta- 
ceae, and others. In some places fertile savannas occur. 

The great volcano Orizaba offers a fine example of the zoning of 
vegetation from the rank tropical jungle at its base, to the regions 



•270 OUTLINE OF PLANT GEOGRAPHY 

of perpetual snow. The first pines appear at 2,200 metres, and the 
oaks reach toaboul 3,400 m., above which for another 1,000 metres 
a Dumber of conifers extend. Above this forest, is an alpine region 
where the vegetation is composed of coarse grasses, and a variety 
of shrubby and half shrubby plants, especially Compositae, 
Labiatae, Rosaceae, etc., as well as some herbaceous species, 
grasses, sedges, Compositae, and others, all decidedly boreal 

types. 

In the upper forest, the epiphytic orchids and Tillandsias of the 
lower elevations, give place to mosses and lichens. 

The western coast of Mexico is much drier, and the tropical 
forest Less developed. Pines and other northern forms grow at 
lower elevations than in the eastern part of the country. 

Central America, 1 Nicaragua, Honduras, Guatemala and Costa 
Rica in the character of their vegetation are intermediate between 
Mexico and equatorial South America. There is a gradual dis- 
appearance of the oaks, pines, and other northern genera char- 
acteristic of the Mexican highlands, and an increasing number of 
palms, and other tropical types. As might be expected, the boreal 
genera ascend to higher elevations as the latitude diminishes, and 
finally disappear completely in the equatorial forests of Panama 
and South America. 

As in Mexico, the Pacific slope of Central America is much 
drier than the Atlantic coast, but nevertheless supports a forest, 
mostly of tropical species, up to an elevation of about 3,000 feet. 
Above this tropical forest belt are open savannas, and still higher, 
forests of pines. 

The eastern slope is covered with a heavy rain-forest, in which 
palms form a very conspicuous feature, these belonging to such 
tropical South American genera as Bactris, Geonoma, Iriartia. 
The central plateau in the more southern part, at an elevation 
of about 5,000 feet, supports a forest in which many trees like the 
silk-cotton and Spanish cedar are leafless during the dry season. 

The forests of Costa Rica are notable for the great profusion 
of ferns and orchids, this being one of the richest regions for these 
plants known to the botanist. Palms, tree-ferns, Scitamineae 
(Canna, gingers, etc.), are very abundant as they are everywhere 
in the tropical American rain-forests. 

1 Drude, loc. cit., p. 509. 



THE NEOTROPICAL REGIONS 271 

South America 

Tropical vegetation in America readies its greatest development 
in the enormous area drained by the Amazon and its tributary s. 
This immense expanse of rich alluvial country lying immediately 
under the equator, and for the most part having an extremely 
heavy rainfall, supports the largest area of tropical rain-forest in 
existence. 

The eastern slopes of the Andes, at the headwaters of the 
Amazon, receive an enormous rainfall, and this region, and the 
portions of the Amazon Valley immediately east of the mountains, 
are covered with a forest growth of unrivalled luxuriance. 1 Further 
down the river are regions of much lighter precipitation where 
open savannas occur, while in northeastern Brazil to the south 
of the mountains of Guiana and Venezuela, the country is said 
to be very arid due to the interception of the moisture-laden winds 
from the Caribbean by the intervening mountains. 

The coastal region, however, from the Amazon delta to and 
including the coast of the Guianas, is one of heavy rainfall, and 
with very dense forests. This northeast corner of Brazil and 
coastal Guiana constitute a very natural botanical province. 

The forests of the Amazon region are of three kinds. 2 First are 
the great forests of the immense regions of the flat valley, which 
are regularly inundated by the flood-waters, and remain covered 
with many feet of water for a long period. All trees and shrubs 
of this flood-forest ("Igapo," "gapo") must be able to survive 
this long submergence. 

Above the gapo is the great virgin forest occupying land above 
the flood-mark, and this is the most extensive and luxuriant 
forest, and contains the greatest number of species. 

Finally, in drier regions are extensive much more open fon 
of relatively low trees, known by the Brazilians as "Caatinga." 

About the middle of the last century the English botanist 
Spruce, spent about fifteen years in the Amazonian country, and 
has given an excellent account of the most important features of 
this vast region. 

1 Bates, H. W., The Naturalist on tin River Amazon, Reprint in Evxbtman'h 

Library. 

2 Spruce, R., Notes of a Botanist on the Amazon and Andes, edited by Alfred Rus- 

sel Wallace, London, 1908. 




272 



THE NEOTROPICAL REGIONS 273 

While there is an immense number of species there are certain 
general resemblances throughout the great Amazonian forest area. 
Thus while the species of the different types of forest, riparian, 
upland and dr} r , are mostly different, the genera are largely the 
same, and some of the most important species occur over a very 
large extent of country. 

The riparian forests, or gapo, are flooded for long periods, and 
the members of this association must necessarily be such species as 
can endure this unusual condition. The trees of the gapo are rarely 
as tall as those of the virgin forest which lies above the high-water 
mark, but the two formations merge into each other at the upper 
limit of the gapo whose outer margin is composed of low shrubs 
and bushes, and many aquatics, like arums, rushes, sedges, etc. 

The gapo is notable for the great variety and abundance of 
palms, many of which overtop the other forest trees, and sometimes 
occur in groves forming long avenues of columnar trunks along 
the shore. 

When the water recedes, the gapo develops a dense undergrowth 
of herbaceous plants, and every tree and shrub is draped with a 
curtain of herbaceous creepers, passion-flowers, morning glories, 
and others, often having flowers of great beauty. 

The virgin forest is distinguished by the very tall and closely set 
trees, whose lofty trunks, often with great buttresses at the base, 
support a thick canopy of foliage which shuts out most of the light. 
so that there is relatively little undergrowth, except young trees 
of the predominant species, and slender palms which earn' their 
crown of leaves toward the light. Stout lianas, like cables looped 
from tree to tree, belong to many species, but their foliage and 
flowers, borne high up in the tops of the trees, are rarely recogniz- 
able from the floor of the forest. This virgin forest covers an 
enormous area in the Amazon valley, the gapo, of course being 
confined to the lowland area subject to the annual inundation. 

The "caatinga" open or white forest, occupies areas of poor 
soil in the drier districts, and is composed of low trees and shrubs, 
with few lianas and palms, the latter when present being peculiar 
forms, quite distinct from those of the wel forest. 

To these might be added the second growth forests, where a 
tangle of trees and shrubs fight with each other for the possession 
of the soil. 



274 OUTLINE OF PLANT GEOGRAPHY 

The "campoe" or savannas, open grassy or scrubby districts, 
occupy but a small part in the valley proper, but north and south 
merge into the great llanos or prairies of Venezuela and Argentina. 

Comparing the different types of the Brazilian forest Spruce 
makes the following statement: 1 "And yet when the constituent 
plants of the different classes of forest come to be compared to- 
gether, they are found to correspond to a degree quite unexpected; 
for although the species are almost entirely diverse, the differences 
are rarely more than specific. It is only in the caatingas that a 
few genera, each including several species, seem to have taken 
up their exclusive abode; such are Commianthus among Rubiaceae, 
Bugamea among Loganiaceae . . . and there are a few other 
peculiar genera, chiefly monotypic. But of the riparial plants 
nearly every species has its congenor on terra firma to which it 
stands so near that, although the two must of right bear different 
names, the differences of structure are practically such as might 
have been brought about by long exposure even to the existing 
state of things without supposing them to date from widely dif- 
ferent conditions in the remote past; this is especially true of such 
genera as Inga, Pithecolobium, Lecythis, and of many Myrtles, 
Melastomes and Sapotads, etc." 

Some characteristic species are very wide-spread. Thus Spruce 
mentions the Brazil nut (Bertholletia excelsa), perhaps the finest 
and most characteristic tree of the virgin forest. It grows almost 
throughout the Amazon valley where the soil is suitable, from 
Para to a point more than 1,200 miles west on the Amazon proper, 
and for many hundred miles up its principal affluents and the 
regions of the upper Orinoco. One of the finest palms, Maxi- 
miliana regia, with huge leaves 30-40 feet long, is even more wide- 
spread. 

As a rule, however, the most wide-spread species do not belong 
to the heavy forest, but to the open savanna. 

Very often a species restricted to a somewhat limited area, is 
replaced elsewhere, under similar conditions by a similar, but 
distinct spec] 

Two types of rivers are found in the Amazon system, clear or 
" black " rivers of which the Rio Negro is the type, and the " white," 
or turbid rivers like the Amazon itself. The riparian vegetation 

1 hoc. cit. 



THE NEOTROPICAL REGIONS 275 

along these two sorts of streams, is very different, but is very 
similar throughout along streams of the same type. Many 
identical species occur in the riparian forest of the Amazon from 
its mouth to the base of the Andes. As a typical example, Spruce 
mentions the "Mulatto" tree (Eukylista sp.) found everywhere 
along the shores of the Amazon, and prized for fuel. 

Like all tidal rivers in the tropics the great delta of the Amazon 
has very extensive mangrove formations, in which the most 
important species, Rhizophora mangle, is the same as in the man- 
grove swamps of West Africa, on the opposite side of the Atlantic. 

Ascending the streams, the mangroves gradually disappear, 
with the decreasing salinity of the water, and are replaced by 
the riparial forest or gapo. 1 The trees of the gapo include many 
Leguminosae, e. g., Inga, Pithecolobium; Brazil nuts, myrtles, 
custard-apples (Sapotaceae), and especially a great profusion of 
palms. 

Trees and shrubs are almost hidden by a dense tangle of creepers. 
These climbing plants include many species with showy flowers, — 
passion-flowers, Bignonias, morning glories, and the less familiar 
Malpighiaceae, very abundant in the American tropics, and with 
showy yellow or pink flowers. Another very striking creeper is 
Cacoucia coccinea (Combretaceae), with brilliant scarlet flowers. 

Just above the inundated area, in the drier waste places, their is 
a dense growth of shrubs and coarse herbaceous plants. Solanum, 
Cassia and \arious other showy Leguminosae, and peppers, some 
being large shrubs, and many climbing plants like those of the gapo. 

The primaeval forest near Para is very vividly pictured by 
Spruce. 2 

"There were enormous trees crowned with magnificent foliage, 
decked with fantastic parasites, hung all over with lianas which 
varied in thickness from slender threads to huge python-like 
masses, were now round, now flattened, now knotted and dow 
twisted with the regularity of a cable. Intermixed with tin 
trees, and often equal to them in altitude, grew noble palms; 
while other and far lovelier species of the same family, their ringed 
stems sometimes scarce exceeding a finger's thickness, but bearing 
plume-like fronds and pendulous bunches of black or red berrii 
quite like those of their loftier allies, formed along with shrubs 
1 Spruce, loc, cit., Vol. 1, p. 4. ' Loc. eii., p. 17. 



276 OUTLINE OF PLANT GEOGRAPHY 

and arbuscles of many types, a bush undergrowth not usually 
very dense or difficult to penetrate. The herbaceous vegetation 
was almost limited to a few ferns, Selaginellas, Sedges, here and 
there a broad-leaved Scitaminea, and (but very rarely) a pretty 
grass (Pariana). ... In some places one might walk for a 
considerable distance without seeing a single herb or even rarely 
a fallen leaf on the bare black ground. It is worthy to be noted 
that the loftiest forest is the easiest to traverse; the lianas and 
parasites (which may be compared to the rigging and shrouds of 
a ship, whereof the masts and yards are represented by the trunks 
and blanches of trees) being in great part hung too high to be 
much in the way; whereas in the low gapo that sometimes skirts 
the rivers, they have not yet got hoisted high enough to allow 
one to pass beneath, but bar the way with an awful array of 
entangled, looped, and knotted ropes, which even the sword 
itself can sometimes with difficulty unloose." 

The Brazil nut and the related monkey nuts (Lecythis spp.) 
are among the commonest and largest trees of the high forest. 
Spruce measured a specimen whose nearly cylindrical trunk was 
42 feet in circumference, and about 100 feet to the first branch. 
This he states was the largest tree he found. The Brazil nut and 
species of silk-cotton (Bombax spp.) are the tallest trees of the 
Brazilian forest, but they probably never exceed 200 feet in height, 

Many of the trees of the virgin forest show an extraordinary 
development of buttresses at the base, which may reach a great 
size. These are especially marked in the silk-cotton trees, but 
Spruce notes that among the laurels, some of the finest trees of 
the Amazonian forest, buttresses were quite wanting. These 
trees have deep roots, and where they predominate is a certain 
indication of deep soil. 

The lianas belong to many families and show much variety in 
the shape of their stems; while the stem of the free swinging forms 
is usually cylindrical, they are sometimes curiously twisted or 
flattened. Spruce 1 cites the case of a leguminous species (Schellia 
splendens), whose flattened wavy stem is sometimes a foot broad, 
and climbs over the trees for 200-300 feet. The trumpet creepers 
{Bignoniaceae) often have strongly angled stems. 2 

While most of these giant lianas are twiners, others climb by 

1 Spruce, loc. cit., p. 28. Ibid., p. 28. 



THE NEOTROPICAL REGIONS 277 

means of stout hooked thorns, which earn for them such popular 
names as " devil's fish-hook," "cat's claws," etc. The rattans of 
the eastern tropics are replaced by a genus, Desmoncus, which 
like its eastern relatives, is dreaded by the explorer in the forest, 
where its barbed-wire entanglements are a formidable obstacle. 
Like the eastern rattans, the prolonged leaf-axis is armed with 
recurved claw-like spines. 

Epiphytes of many kinds abound in the equatorial forest. 
Among the most notable are many aroids, and species of Cyclan- 
thaceae, the latter looking like small palms, and confined to the 
American tropics. These, as well as some of the Araceae, develop 
thick, pendent aerial roots, which hang down like plumb-lines, and 
may sometimes reach the ground. Aerial roots are also common 
in epiphytic orchids, but as a rule are too small to attract attention. 
Many aroids climb up the trunks of the trees by means of the 
aerial roots, and the leaves of some of them are of gigantic size. 

While epiphytes are developed to a remarkable degree in the 
high forest, they are often quite invisible from below, as they 
grow far aloft in the crowns of the trees. 

The Cyclanthaceae, referred to above, have terrestrial species 
as well, among them the species of Carludovica from whose leaves 
are manufactured the Panama hats. 

Another peculiarly American family, the Bromeliaceae, also 
largely epiphytes, includes the pineapples, and the "Spanish 
moss" of our Gulf States. The family is very abundantly rep- 
resented throughout tropical America, most of them resembling 
the pineapple in habit. Some have showy flowers, or the inflores- 
cence is surrounded by brightly colored leaves. 

Epiphytic orchids are common, but are less conspicuous than 
in the mountain forest or the lower and more open forest of the 
caatinga. Small epiphytic peppers (Peperomia spp.) are also 
abundant, and the scarlet Aeschynanthus of the Malayan regions 
is replaced by related, but different genera of Gesneraceae. 

Strangling figs, like those of the eastern tropics, occur in the 
Amazonian forest, but are less common than in the Andean region, 
and some other parts of tropical America. 

In the dark virgin forest the herbaceous undergrowth is scanty: 
but in the lower wet forest there is a rank growth of ferns, Araceae, 
Scitamineae (bananas, gingers, arrow-root, etc.). These are 



278 OUTLINE OF PLANT GEOGRAPHY 

mostly differenl genera from those of the old world, but there are 
some genera m common: e. g., Costus, Thalia; and Cannas of 
several species are frequent, their showy red or yellow flowers 
lighting up the open places at the edge of the forest and spreading 
as a weed into waste ground. The Canna family is peculiarly 
American, although some have become naturalized as weeds in 
the old world. The banana family (Musaceae), gingers (Zingi- 
beraceae), and arrow-roots (Marantaceae), are also represented 
in the old world, but mostly by different genera. 

There are no true bananas native to America, but the family 
is abundantly represented by several species of Heliconia, hand- 
some plants with banana-like foliage, and brilliant red and yellow 
floral bracts. Another interesting member of this family is Ravenala 
Guianensis, closely related to the famous ''traveller's tree" of 
Madagascar. 

The gingers of the genus Costus have handsome orchid-like 
flowers, and the Marantaceae have leaves often of velvety texture 
and beautifully variegated. These are sometimes seen in cultiva- 
tion. 

Among the many conspicuous Araceae growing in low wet 
ground is Montrichardia arborescens which forms dense thickets 
along the river banks, the tall, bare, palisade-like stems bearing a 
tuft of big arrow-shaped leaves. These aquatic aroids and the 
many other aquatics associated with them, sedges, grasses, pickerel- 
weeds (Pontederiaceae), etc., form the outer fringe of the gapo, 
and inland are replaced by the shrubs and trees which occupy 
the land exposed by the subsiding water. 

Another common and conspicuous genus of terrestrial Araceae 
is Caladium, whose arrow-shaped leaves are beautifully marked 
with white and crimson, which in cultivation have produced many 
extremely beautiful varieties. The large genus Anthurium is also 
prized in cultivation, both for the handsome foliage of some species, 
and the showy white or red Calla-like inflorescences of others. 
Of the climbing Araceae, Philodendron and Monstera are perhaps 
the most conspicuous. Their gigantic leaves are often fantastically 
cut and perforated, and at once attract attention. M. deliciosa 
is often seen in conservatories where its big perforated leaves and 
thick spikes of edible fruit at once attract notice. 

The equatorial forests of South America have little in common 



THE NEOTROPICAL REGIONS 279 

with those of temperate North America or Eurasia. The conif- 
erous trees are absent, and deciduous trees are almost entirely 
wanting. The characteristic deciduous trees of the boreal forests, 
oaks, beeches, chestnuts, walnuts, poplars, birches, maples, etc., 
are entirely unrepresented. A single willow (Salix Humboldtii), 
which is common in the Amazon district, is about the only repre- 
sentative of the catkin-bearing trees. It is true that in the warmer 
parts of the United States, especially in southern Florida, which 
almost touches the tropics, there are a good many trees and shrubs 
which are evidently outposts of the tropical vegetation which 
culminates in the great Amazonian forest. 

Our locusts and mesquit represent the great family of Legumi- 
nosae, which probably has the greatest number of species in the 
equatorial forest, and the sassafras and in the south Persea, a 
tropical genus which includes the " avocado," represent the laurels 
which have many tropical genera and species. Other cases might 
be cited, but they are relatively unimportant. 

Rivalling the Leguminosae in number are the species of the 
madder family (Rubiaceae). The most important of these, 
Andean, however, rather than Amazonian, is the genus Cinchona, 
the source of quinine. The Rubiaceae of temperate climates 
are mostly insignificant herbs, like the bedstraws (Galium) and 
the little bluets (Houstonia) of the Atlantic States. Both in the 
Palaeotropics and Neotropics, a very large number of trees belong 
to this family. 

The Leguminosae comprise an enormous assemblage of trees, 
shrubs, and lianas, many of which have extremely abundant and 
showy flowers at certain seasons. The sub-family Mimoseae 
often have delicately cut graceful foliage, and flowers with clusters 
of slender stamens, e. g., Inga, Pithecolobium; or like Cassia and 
Bauhinia of the sub-family Caesalpineae, the flowers are open, 
often suggesting an orchid. The pea-flowered type (Papilionaivae), 
is less common, but still abundantly represented. 

The fig-family (Moraceae) includes a large number of species 
other than Ficus. Among these are bread-fruits (Artocarpus 
spp.), and other genera, one of the most not:il>lr being Cecropia, 
a genus of trees, usually of comparatively small size, growing in 
the riparian forest. They have hollow branches in which colonics 
of ants are said to have their abode, and the long-stalked palmate 



280 OUTLINE OF PLANT GEOGRAPHY 

leaves, usually woolly beneath, are suggestive of the castor-bean. 
The Cecropias are everywhere abundant and conspicuous in the 
wet American tropics. 

The myrtle family is an important one in tropical South America, 
and comprises many species of Eugenia, Myrcia, Psidium, and 
others. Several species of the latter genus, yield the well-known 
guavas, now extensively cultivated in most tropical and some sub- 
tropical countries. 

Among the giants of the Amazonian forest are the silk-cottons 
(Bombax, Ceiba) whose huge trunks are supported by enormous 
buttress-roots. The silky down attached to the seeds of some 
species furnishes the silk-cotton or " Kapok" used for stuffing 
mattresses and similar purposes. 

Of the many trees yielding useful commercial products, the Para 
rubber (Hevea Braziliensis) takes first place, and until quite re- 
cently was the most important export from Brazil. It belongs to 
the Euphorbia family, and is a tree of moderate size with trifoliate 
leaves, something like a Laburnum. It grows in the low forest 
over much of the Amazon valley, and now is cultivated on a great 
scale in many tropical countries, but with especial success in various 
parts of the Malayan regions, where the plantations furnish most 
of the rubber requirements of this age of automobiles. Another 
large and common tree of the same family, the " sand-box" (Hum 
crepitans) is abundant in the virgin forest. 

The custard-apples (Anonaceae), and the sapodillas (Sapota- 
ceae), include many important fruits of the Amazonian region, 
some of the latter also furnishing that remarkable substance 
"chicle," the basis of one of America's noblest products, chewing 
gum. 

The Brazil nut represents the purely tropical family Lecythi- 
daceae, especially developed in northern Brazil, while the " Spanish 
cedar" (Cedrela spp.), and species of nutmeg (Myristica spp.), are 
also characteristic of the old world tropics. 

These are but a few samples of the thousands of species of trees 
that make up the great equatorial American forest. 

Palms are much more conspicuous than in most parts of the 
eastern tropics. Whether the number of species is greater might 
be questioned; but as regards conspicuous arborescent species, 
there is no question that the American tropics surpass any part of 



THE NEOTROPICAL REGIONS 281 

the old world. Leaving out the coco-palm which has been dis- 
tributed over the tropics of the whole world, the American palm-. 
with two significant exceptions, belong to genera quite unrepre- 
sented in the eastern hemisphere. 

The fan-palms of the genus Mauritia are very abundant, but 
the pinnate-leaved genera are much more numerous. Some like 
the wide-spread Maximiliana regia have immense leaves 30—40 
feet long, and recall the sugar-palms of the East Indies. A par- 
ticularly abundant and beautiful species is Euterpe oleracea, with 
slender stems, and graceful feathery leaves. This occurs in great 
numbers along the banks of the northern South American rivers. 
The genus Bactris, mostly small palms, often with clusters of showy 
black or red berries, is very common in the undergrowth of the 
forests, and other small palms (Geonoma spp.) with almost en- 
tire leaves are also abundant. The only climbing species belong 
to Desmoncus, which in habit is much like the rattans of the eastern 
tropics, but is really not closely related to them. 

Many palms are very important economically, the fruits furnish- 
ing food, while the stems and leaves yield fibres, and building 
material for the primitive dwellings of the natives, the leaves being 
the usual thatch for the roofs. The " peach-palm" (Gulielma 
speciosa) is extensively cultivated for its fruit, but according to 
Bates 1 is unknown in a wild state. It bears immense clusters of 
fruits of the size of a peach, which they resemble in color. They 
are very nutritious, and an important article of diet among the 

natives. 

In the virgin forest the trees are so tall that even when they bear 
showy flowers, they are scarcely perceptible from below, and the 
general effect is that of luxuriant foliage with {lowers rare, or 
inconspicuous. Indeed a large proportion of both trees ami shrubs 
have inconspicuous flowers, although there are numerous excep- 
tions. In the more open forest, and along the banks of streams. 
there is sometimes a very magnificent display of flowers, and there 
are some lofty trees, which in their flowering season are covered 
with masses of brilliant bloom. 

Spruce 2 states that near Para the Legumino>a<- and Bignoniaceae 
furnished the greatest number of showy trees and lianas. Among 
the former are species of Cassia, Sclerolobium and Bauhinia. The 

^Loc cit., p. 290. 2 Loc.cit., ]>. 41. 



282 OUTLINE OF PLANT GEOGRAPHY 

Bignoniaceae include many extremely showy creepers and trees, 
the latter being mostly species of Tecoma, allied to the common 
trumpet creeper. Other trees with showy flowers belong to the 
Myrtaceae, Kubiaceae, Lecythidaceae and Bombacaceae. 

Mention has already been made of the showy-flowered lianas — 
passion-flowers, Bignonias, Malpighiaceae, etc., and the showy 
herbaceous plants: Heliconia, Caladium, Canna, etc. of the wet 

gapo. 

The Amazonian forest reaches its maximum development in the 
portion of the river above its junction with the Rio Negro. Between 
this and the foot of the Andes there is an excessively heavy rain- 
fall, and the whole country is covered with unbroken forest which 
ascends to 3,000-4,000 feet on the eastern side of the mountains. 

A tropical rain-forest much like that of the Amazon valley in 
its composition is found along the eastern coast of Brazil from 
Pernambuco southward to a point beyond the Tropic of Capri- 
corn. This includes Rio Janeiro, and the adjacent country. 

The interior plateau rises to the east and near the coast forms an 
escarpment which is cut by many abrupt gorges, and the edge of 
the plateau forms two broken ranges of mountains parallel with 
the coast. The seaward slopes of these ranges, and the coastal 
plain, when present, receive a copious rainfall, which together with 
uniformly high temperatures, develops a luxuriant rain-forest 
which extends far south of the Tropic of Capricorn, but finally 
loses its tropical character and merges with the temperate vegeta- 
tion of the coast of Argentina. 

Forming the eastern boundary of the great Amazon basin are 
the extensive continental highlands of Brazil, whose eastern edge 
consists of the coastal mountain ranges already mentioned. 
Inside this coastal mountain rim, the plateau slopes westward to 
the Amazon valley, but is much broken up by mountain masses 
of greater or less extent. From the mouth of the Amazon to Uru- 
guay, this great table land is drained by many rivers belonging to 
the Amazon system. 

The rainfall is fairly heavy over much of the plateau, but a good 
deal of the country is semi-arid, and the vegetation more or less 
decidedly xerophytic. Extensive savannas suited for grazing, 
and open forest cover large areas. 

The dry open forest "caatinga" is a feature of much of the 



THE NEOTROPICAL REGIONS 283 

plateau. The trees are low, and often thorny, and arc associated 
with shrubs of many kinds. Many of both trees and shrubs cast 
their leaves in the dry season. In the caatinga are found many 
Cacti, Bromeliads, and other succulents, and there is a marked 
development of bulbous plants, which are only evident in the 
rainy season, when the trees renew their foliage, and many are 
adorned with showy flowers. 

Southern Brazil has a remarkably large number of extremely 
showy trees, shrubs and climbers, many of which adorn the gardens 
of the warm temperate zone, like the Riviera, California and Aus- 
tralia. The well known Bougainvilleas, Bignonias, and passion- 
flowers, mostly come from this region, and the Jacaranda with its 
delicate foliage and masses of beautiful blue flowers. 

The caatinga of Brazil may be compared to the bush-veldt of 
the south African plateau. 

In the region of the Orinoco, according to Spruce, the caatinga 
formation is mainly due to poor soils, and the trees are evergreen 
with the profusion of epiphytic growths associated with a humid 
atmosphere. 

The coastal mountains of Venezuela and the adjacent region of 
Colombia show a large percentage of deciduous trees. As one sails 
in sight of these coasts in the summer, the mountain slopes present 
a very dreary picture due to the large number of bare deciduous 
trees. This is a striking contrast to the rich evergreen vegetation 
of the Guiana lowlands and Trinidad, and more resembles the 
caatinga of the eastern Brazilian highlands. 

The tropical Amazonian forest ascends the eastern slopes of the 
Andes to a height of 3,000-4,000 feet, above which there is a gradual 
increase of temperate types and a corresponding disappearance of 
the lowland species. 

The eastern slopes of the Andes, at the headwaters of the Ama- 
zon have an extremely heavy precipitation, and the difficulties of 
exploring these dense forests have been graphically described by 
Spruce who spent several years in this region. Owing to their 
inaccessibility, as well as the fevers and other drawbacks to ex- 
ploration, these forests are still very imperfectly known. 

Except where the forests have been cleared there is little open 
country at the lower elevations, although there are a few spots, 
which owing to their topography, are relatively dry, and free from 



284 OUTLINE OF PLANT GEOGRAPHY 

heaw forest Ferns, mosses and liverworts become much more 
abundant in the Andean mountain forests, and become extraor- 
dinarily developed, a phenomenon to be noted everywhere in the 

tropi« s. 

Spruce found the development of mosses and liverworts especi- 
ally great in the region known as the "montana of Canelos," 
in the neighborhood of the great volcanoes of Cotopaxi and Tung- 
uragua. This forest which extends from 1,000-5,000 ft. elevation 
is wry wet. and Spruce says the growth of these plants is the 
most luxuriant he had ever seen. "Even the topmost twigs and 
the very leaves were shaggy with mosses and from the branches 
overhanging the river depended festoons of several feet in length 
composed chiefly of Bryopterides ... in beautiful fruit." 

So great is the load of mosses, that when soaked with water they 
often broke off the branches to which they were attached. 

A very interesting plant of this forest was a giant horse-tail 
Equisetum sp.) t twenty feet high and with a stem almost as thick 
as one's wrist. 

Palms are common in these mountain forests, but less varied 
than in the lowlands. The commonest species is Iriartea ventri- 
cosa. which forms extensive groves. Species of Wettinia and 
Euterpe are also characteristic of the Canelos forests, and also 
the vegetable-ivory palm (Phytelephas sp.). 

The most important trees of the Andean forest are several 
species of Cinchona yielding quinine. Spruce's long sojourn in 
this region was mainly for the purpose of securing young plants 
and seeds of the most valuable species, the "Red-bark" (C suc- 
cirubra). Different species are found at elevations from 2500 to 
10,000 feet iccirubra growing from 2,500 to 5,000 ft. The plants 

and seeds sent by Spruce to England marked the beginning of 
the cultivation of Cinchona in the tropical British colonies, which, 
however, have never met with the success of the plantations in the 
Dutch East Indies, especially Java, which now furnishes a large 
part of the world's supply of the drug. There are now, also, 
plantations of Cinchona in Colombia and other parts of the An- 
dean region. The family Rubiaceae, to which Cinchona belongs, 
has furnished another plant of great importance, viz., coffee, 
now grown in immense quantities in southern Brazil, which fur- 
nishes the greater part of the commercial product. 




Plate XXX. 



•Riparian forest, Para River, Surinam. € olcracea. 

HeUooma q*. 



l?bo 



286 OUTLINE OF PLANT GEOGRAPHY 

The Cinchona region has a flora of the same general type as that 
of the Amazonian forest, and a good many of the same species. 
Bamboos and other giant grasses are a feature of this region, 
among them the giant arrow-grass (Gynerium saccharides), re- 
lated to the familiar "pampas-grass" of the gardens, but sometimes 

30-40 feet high. 

There are many orchids, but mostly inconspicuous species. 
The richest collecting grounds for showy orchids are further 
north in the mountains of Colombia, and Central America, from 
which come many of the choicest ornaments of our conserva- 
tories. The many species of Cattleya, Odontoglossum and On- 
cidium, and other extensively cultivated orchids, come from these 

countries. 

Exeept in the higher altitudes, the trees and shrubs of the moun- 
tain forest belong to the same families as those dominating the 
forest lower down, e. g., Rubiaceae, Leguminosae, Myrtaeeae, 
Malpighiaeeae, etc. At higher elevations, however, temperate 
genera occur, and at the highest altitudes there is a distinct alpine 
flora. In the cool highlands we may find such familiar northern 
plants as brambles, mallows, chick-weed, huckleberries, pig-weed 
(Chenopodium), Geranium, catch-fly and a good many others; 
but there are also certain distinctly Andean genera, like Fuchsia, 
and Calceolaria, while the sub-alpine flowers including gentians, 
valerian, paint-brush (Castilleia) and lupins, remind one of the 
sub-alpine flora of the Californian mountains. 

The western slopes of the Andes are much dryer, and as Spruce 
say< "The Amazon side of the Andes is incomparably richer than 
the Pacific side." The former has a continuous rainy season with 
little variation in temperature, while the Pacific slope has a long 
dry season, and much of the coastal part of Peru, Ecuador and 
northern Chile is an absolute desert where rain is almost unknown, 
and except along the streams descending from the mountains, 
vegetation is often completely absent. 

The writer's first-hand impressions of the equatorial South 
American vegetation are derived from brief visits to Panama, 
Guiana, and Trinidad, where, however, the vegetation is very 
much the same as that of the Para district of the Amazon. 

The coast of the Guianas is mostly low and swampy, and the 
tide extends for a long way up the rivers, whose lower reaches 







M ' •'it'* f. 






*>s 



:•&«■ 



^«> 





2* + 

*• > 

,' 4 


vf 


- 




*r 


• /* 




» 

• 




/* ■"■ 


fa 








# ** *"• * 


:- > 


« 










■ 


'. ' - ■ * . 


■~^ 


















. 



' 



Plate XXXI.— Riparian forest, Para River, Surinam. 

in background. 



>pia palmata (?) 






288 OUTLINE OF PLANT GEOGRAPHY 

are bordered by impenetrable mangrove swamps composed al- 
most exclusively of Rhizophora mangle, the common American 

species. 

As one ascends the stream, the Rhizophora gives way to the 
•white mangrove/' {Avicennia hitida) which sometimes becomes 
a large tree with very long aerial roots pendent from the upper 
branches. Back of the mangrove belt are slightly elevated ridges 
upon which grow large trees of various kinds. 

Still higher up the rivers, the mangroves disappear completely, 
and the banks are overgrown with a dense jungle of trees and shrubs 
corresponding to the gapo of the Amazon. Leguminosae of many 
species are especially abundant, particularly species of Inga; and 
the big arum, Montrichardia arborescens, already referred to, forms 
a close palisade at the outer margin of the jungle. 

Continuing above the tide limit palms become a conspicuous 
element in the forest, and along the banks, and in the typical 
riparial forest occur in large numbers and variety, and add a great 
charm to the river shore. First in abundance and beauty is 
Euterpe oleracea, whose tall slender stems and feathery crowns 
occur in thousands. Other characteristic palms are species of 
Maximiliana and Attalea, with gigantic pinnate leaves, and less 
striking species of Astrocaryum and Manicaria. Of the smaller 
palms occurring as undergrowths in the forest, the commonest are 
many species of Bactris, with slender stems, sometimes hardly an 
inch thick, and with clusters of showy red or black berries. The 
climbing species of Desmoncus, already referred to, are very com- 
mon. Their flexible spiny stems, and graceful feathery leaves, 
armed with savage hooked spines, are festooned from tree to tree, 
and remind one of the East Indian rattans. The clusters of scarlet 
fruits are very conspicuous, and attract attention, as the boat 
skirts the dense jungle along the shore. 

Next to the palms, perhaps the most striking trees of the riparial 
forest are the numerous Cecropias, with their big palmate leaves 
and jointed stems, which occur everywhere along the rivers. 

A bewildering tangle of climbing plants forms a heavy drapery 
over trees and shrubs, sometimes quite concealing them. These 
lianas belong to very diverse families, and include morning glories, 
passion-flowers, trumpet creepers, as well as less familiar genera 
of Apocynaceae, Melastomaceae, Malpighiaceae and others. 




Plate XXXII. — Lowland forest interior, Surinam. 



289 



290 OUTLINE OF PLANT GEOGRAPHY 

Many of these have flowers of great beauty which are admirably 
set off by the background of luxuriant jungle foliage. 

The primaeval forest in the vicinity of Paramaribo in Surinam 
(Dutch Guiana) is largely a swampy one, but with elevations of 
drier sandy soil where the tallest trees grow. The largest trees 
of this forest are the silk-cotton (Ceiba pentandra) and the sand- 
box (Hum crepitans) which reach gigantic size. 

The trunks and branches of these great trees are covered with 
numerous epiphytes, among which the Bromeliads take first 
place. Several species of Tillandsia, including the " Spanish 
moss" of the southern United States, were the most abundant of 
these. Clinging to the trunks of the trees, or festooned from tree to 
t ree, were many lianas, some of great size. These included morning 
glories of several kinds, Bignonias, and especially the great climb- 
ing aroids: — Monstera, Philodendron, Syngonium, and others, 
which were conspicuous in the tangle of creepers. 

A luxuriant undergrowth of dwarf palms, Cannas, Heliconias 
and showy arums, gave the finishing touch to a truly tropical 
picture. 

Ferns, mosses and liverworts are not abundant in this forest, 
and this seems to be true of much of the Amazonian forest region, 
to judge from Spruce's notes. A few epiphytic ferns, species of 
Vittaria and Polypodium were noted at Paramaribo, but they were 
not specially abundant. 

A very different type of vegetation is found in the savannas 
which are sometimes met with in the coastal regions of Guiana. 
One of these visited by the writer was an expanse of coarse gritty 
soil' covered with a sparse growth of coarse grasses and sedges, 
with scattered clumps of low shrubs. A number of terrestrial 
orchids were seen, but only one of these, a Catasetum, was in 
flower. The flowers of this curious species are quite large, greenish 
in color. 

Here and there were shallow pools in which grew tiny bladder- 
weeds (Utricularia) with yellow flowers, and minute rush-like 
plants belonging to the families Eriocaulaceae and Xyridaceae. 
Small patches of Sphagnum grew under the bushes, and in these 
were little sundews (Drosera sp.) reminding one of the northern 
peat-bogs. A beautiful blue gentian (Chilonanthus sp.) was com- 
mon, and a few ferns, including the common bracken, were noted. 




Plate XXXIII. — Jungle interior, Surinam; ut left, Ravenala Guianenris. 



2UI 



292 OUTLINE OF PLANT GEOGRAPHY 

The shrubs for the most part belonged to the mainly tropical 
families Malpighiaceae, Melastomaceae and Rubiaceae. To the 
latter belonged an undetermined shrub with a profusion of large 
rose-colored flowers. A butterfly-pea (Clitoria sp.) with large 
purple flowers, was also common. 

The outstanding feature of this savanna was a noble fan-palm 
(Mauritia flcxuosa) which formed groves of considerable extent. 

Surrounding the savanna was a forest occupying rather dry 
soil, and traversed by clear streams, but with areas of boggy 
soil. Palms were abundant as an undergrowth, and a very interest- 
ing plant was a sort of wild banana (Ravenala Guianensis) much 
resembling its congener the traveller's tree of Madagascar. Ferns 
were more abundant than in the forest about Paramaribo, but 
still played a very subordinate role in the vegetation. 

One of the common trees of this forest is the "Balata" (Mimu- 
sops sp.) belonging to the Sapotaceae. This yields a rubber of 
fair quality, but much inferior to the Para rubber. 

The writer was struck with the abundance of showy flowers in 
the neighborhood of Paramaribo, a rather unusual condition in 
the wet tropics. The showy climbers have already been noted, 
and were especially abundant. A rose-red passion-flower, and the 
big golden bells of an Allamanda (Apocynaceae), were truly 
magnificent, and many of the shrubs, Leguminosae, Rubiaceae, 
Melastomaceae, Malphighiaceae, bore very abundant and showy 
flowers. 

Of the herbaceous plants perhaps the most notable were the very 
common Heliconias, looking somewhat like Cannas, or the larger 
species like bananas. The brilliant scarlet and yellow bracts of 
the flower clusters are extremely showy. Red and yellow Cannas 
were also very abundant, and wild ginger (Costus sp.) and arrow- 
root (Maranta spp.) were common and handsome forms, and with 
these were growing Caladiums with gayly painted arrow-shaped 
leaves. 

This brilliant floral display was seen at the edge of the forest, 
and in open places, such as railway embankments, which were 
veritable flower gardens. Red and yellow milkweed, weedy Com- 
positae and Verbenaceae were everywhere common. 




Plate XXXIV.— Savanna vegetation, Surinam. Mauritia flexuoM, 



293 



294 



OUTLINE OF PLANT GEOGRAPHY 



Trinidad 

The island of Trinidad while separated from the mainland of 
South America, nevertheless has a vegetation closely resembling 
that of the adjacent coast. The wetter lowland forest abounds 
in palms, aroids, Scitamineae, etc., identical with, or closely 
related to those of the coastal belt of the Guianas. 




A B 

Fig. 80. — A. Tree with epiphytic ferns, Port of Spain, Trinidad. 
B. Palm (Attalea sp.), Para River, Surinam. 

The drier hillsides, however, show a quite different vegetation, 
such as a very common palm (Acrocomia sclerocarpa) , common in 
Jamaica and other islands of the Antilles. Ferns are decidedly 
more abundant than in Guiana, although not especially conspic- 
uous in the lower forest. Two particularly interesting species were 
noted near Port of Spain, viz: A climbing fern (Lygodium sp.) 
and Anemia phyllitidis. In the lowland wet forest ferns were more 
abundant, but much less so than at higher elevations. 

Port of Spain, with its fine botanical garden and attractive 
parks, offers much of interest to the botanist. There are many 
species of palms, native and exotic, and splendid specimens of 



THE NEOTROPICAL REGIONS 



295 



other native trees. Of the commonly planted palms, the finest is 
Oreodoxa oleracea, the "Palmiste" of the French, " cabbage-palm ' : 
of the English, a much handsomer species than the royal palm 
(0. regia) with which it is sometimes confused. 0. oleracea, with 
its perfectly cylindrical trunk, sometimes more than 100 feet 
high and its magnificent crown of rich plumes, is perhaps the fin- 
est of all palms. 




Fig. 81. — Lowland vegetation, Trinidad. At left, "groo-groo" palm (Acrocomia 

sclerocarpa) . 

Silk-cotton trees, sand-box, Spanish cedar (Cedrela odor aid) } 
and mahogany, are commonly planted, and enormous specimens 
of the wide-spreading " monkey-pod ,; (Pithecolobium saman) 
adorn some of the parks. The curious cannon-ball tree (Couropita 
Guianensis), related to the Brazil nut, is sometimes seen, the large 
red flowers, borne upon short branches growing directly from the 
main trunk, and followed by big globular fruits to which it owes 
its popular name. 

In the low wet forest near Port of Spain, then 1 was a luxuriant 
growth much like that in Guiana. A fine arum (Spathiphyllum 
cannae folium) was very abundant along the streams. the Lai 
white spathe recalling the common calla, while other handsome 
members of the same family, e. g., Montrichardia, Philodendron, 
Anthurium, were abundant. Epiphytic orchids were frequent, 



296 OUTLINE OF PLANT GEOGRAPHY 

but mostly out of flower at this season (June), but several very 
handsome flowers were noted, especially Bromeliads with brilliant 
red bracts, and the wild "Poinsettia" (Warczewicria coccinea), in 
which one of the calyx-lobes is greatly enlarged and bright scarlet 
in color. Big clumps of Heliconia bihai gay with the bright red and 
yellow flower-spikes, made fine masses of color amid the rich 
foliage, and presented a magnificent picture of tropical vegetation 
in its fullest development. 

Savannas, like those in Surinam, also are found in Trinidad. 
One of these visited by the writer, the Aripa savanna, was much 
like the one already described, but the vegetation was more luxuri- 
ant. The fan-palm of Guiana was represented by an even finer 
species, Mauritia setigera, forming groves of considerable size. 
Ground orchids, sundews, and bladder-weeds were abundant, but 
like the palms, different species from those of Surinam. An in- 
teresting fern, Schizaea pennula, and two club-mosses, Lycopodium 
cernuum and L. Carolinianwn, were noted among other plants. 

A fine forest adjoined this savanna, with many beautiful palms: 
Euterpe, Bactris, Attalea and Maximiliana, and there was an 
abundant growth of epiphytes, including some small filmy-ferns. 

Among the trees in this forest, were numerous species of Clusia, 
a peculiarly American genus, some of which begin life as epiphytes, 
sending down aerial roots which finally strangle the host tree. 
These parasitic Clusias, with their glossy magnolia-like leaves, 
are very handsome, and resemble some of the strangling figs of 
the eastern tropics. 

The highest mountain of Trinidad, Tucuchi, has an interesting 
flora. The lower part of the mountain is largely occupied by plan- 
tations of cacao (Theobroma cacao), but the upper part is covered 
with heavy primaeval forest. At about 1,500 feet one enters a 
splendid forest of lofty trees, with a heavy undergrowth of ferns, 
palms, Heliconias, and various aroids, with shrubs and lianas 
in great variety, altogether a fine example of a tropical rain-forest. 

At the top, some 3,000 feet elevation, the trees are smaller, but 
dwarf palms were still abundant, and ferns were numerous and 
beautiful. Several fine tree-ferns were common, and among others, 
the most interesting were several species of Danaea, a member 
of the ancient order Marattiales. The prothallia of these ferns 
were abundant, and so large that they may be easily taken for 




Plate XXXV. — Jungle near Port of Spain, Trinidad. 



297 



298 



OUTLINE OF PLANT GEOGRAPHY 



liverworts. Of the latter there were many interesting species, with 
club-mosses and lichens in profusion. 

One of the most interesting of the epiphytes, is a species of 
bladder-weed (Utn'cularia montana), whose drooping racemes of 
large white flowers might well be mistaken for an orchid. 

To the botanist who visits equatorial America for the first time, 
the 4 abundance and variety of palms will probably first attract atten- 




A B 

Fig. 82. — A. Cannon-ball tree (Couropita Guianensis), Port of Spain, Trinidad. 
B. Cabbage-palms (Oreodoxa oleracea), Port of Spain. 

tion. There are many exceptionally beautiful species, and as they 
often are gregarious, they give a characteristic stamp to the forest 
vegetation. They are a much more conspicuous feature than in 
any part of the eastern tropics with which the writer is acquainted. 
The Araceae, too, are more numerous and varied than in the 
tropics of the old world, and none of the old world species can rival 
the giant climbing species like Anthurium, Philodendron, and 
Monstera, so characteristic of the American tropics. 




Plate XXXVI.— Silk-cotton tree (Cei6a pentandra), Port of Bpain, Trinidad. 



j'.t<< 



300 OUTLINE OF PLANT GEOGRAPHY 

The Galapagos Islands 

The Galapagos Islands, 580 miles west of Ecuador and lying 
directly on the equator, are of great interest both to the zoologist 
and the botanist. 

The islands are entirely volcanic in formation and attain a 
height of 2,000 to 2,500 feet. Both animals and plants give evi- 
dence of a very long period of isolation. 

The most comprehensive account of the vegetation is given by 
Professor B. L. Robinson with the co-operation of several other 
specialists. 1 

The climate is very hot and dry, and at the lower elevations the 
vegetation is decidedly xerophytic, made up of scattered small- 
leaved shrubs, wiry grasses and undershrubs, and a few tree 
Cacti. 

Inland are saline lakes, and about these and in brackish swamps, 
as well as along the coast, are a good many saline plants or "hal- 
ophytes." First in importance are the mangroves (Rhizophora 
mangle, Avicennia officinalis), while other characteristic forms are 
species of morning glories (Ipomoea, Calystegia), Verbena, 
Heliotropium, Atriplex, and several others. 

Epiphytes are infrequent, but there is a Bromeliad (Tillandsia) 
and an orchid (Epidendrum) and several species of Peperomia. 
Showy flowers are scarce. 

As to the origin of the Galapagos flora, Robinson says: "While 
it is clear that the Galapageian flora is only an outlying portion 
of the American flora ... it is impossible to trace its relation- 
ship closely to any one section of the Pacific American vege- 
tation." 2 

Omitting the algae, fungi and bryophytes, which have a few 
peculiar species, there are 499 species of vascular plants recorded. 
Of these 52 are ferns and 445 spermatophytes (flowering plants). 
Only three ferns are endemic, while 202 species, 15 varieties, and 
19 forms constituting 44.4 per cent of the whole spermatophyte 
flora are peculiar to the islands. 

"Flora of the Galapagos Islands" (Papers from the Hopkins-Stanford Expedi- 
tion to the Galapagos Islands), Proceedings of the American Academy of Arts and 
Sciences, Vol. XXXVIII, No. 4, October, 1902. 
2 hoc cit., p. 239. 



THE NEOTROPICAL REGIONS ;;m 

The Antilles 

Aside from Trinidad, which is essentially South American in 
its flora, the archipelago of the Antilles or West Indies, in the 
Carribbean Sea, has a sufficiently individual flora to warrant 
separating the West Indies from continental America, as a distinct 
botanical province. Each of the larger islands has many peculiar 
species, but there are many common to other islands, and to the 
Mexican and central American mainland. The southern end of 
Florida, with the "keys," is essentially West Indian in its flora, 
and has many species in common with the islands. Examples 
of these West Indian species are Pinus Cubensis, the royal palm 
(Oreodoxa regia), mahogany, and species of figs, orchids and many 
ferns. 

The larger islands are all very mountainous, the mountains 
in Haiti exceeding 10,000 feet in height, while in Jamaica, the Blue 
Mountains are over 7,000, and in Cuba the highest summits exceed 
8,000. The trend of the ranges is mostly east and west, and this, 
together with their elevation, exercises a marked influence on the 
climate. The northeast trade-winds precipitate their moisture 
mostly on the northern slopes of the mountains, the lee side being 
much drier. This is well shown in Jamaica in making the journey 
from Port Antonio on the north coast, to Kingston on the south 
side of the island, about 40 miles away, the two places separated 
by the high and steep range of the Blue Mountains. At Port 
Antonio the annual rainfall is nearly 200 inches, while at Kingston 
it is less than 40. The whole northern coast was originally clothed 
with dense jungle, a typical rain-forest of great luxuriance. 

About twenty-five years ago, when the writer first visited Ja- 
maica, the newly constructed railway between Port Antonio and 
Kingston traversed a region of luxuriant forests, which have since 
disappeared, and been replaced by extensive plantations of ba- 
nanas, which are grown on an immense scale for the American 
market. Of late years this trade in bananas and other tropical 
fruits has assumed vast proportions, and has been extended to 
Mexico and Central America, as well as to the other West Indian 
islands. 

The mountains intercept a la rue part of the moisture of the trade 
winds, and when one approaches Kingston, instead of the rain- 






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302 



THE NEOTROPICAL REGIONS 303 

forest one sees an open semi-arid plain or savanna with Cacti, 
mesquit, and Agaves, suggesting the semi-deserts of Mexico and 

Arizona. As in those countries there is a dry winter, most of the 
rain falling in the summer months. 

In the Blue Mountains, the lower rain-forest extends to about 
2,000 feet elevation and in general is quite like the South American 
equatorial forest, but is much poorer in palms. Araceae and the 
showy Heliconias are conspicuous, and ferns are much more abun- 
dant than in the lowland forest of South America. 

Above this forest is a rain-forest of somewhat mixed character; 
mingled with laurels and other tropical types are genera common 
to the forests of temperate America, like walnuts, and Clethra, 
the latter belonging to the Ericaceae. The yew family is repre- 
sented by species of Podocarpus, already referred to in connec- 
tion with the floras of the East Indies and Australasia. 

In the drier hot lowlands are found trees which shed their leaves 
at certain seasons. Among these are the giant silk-cottons 
(Ceiba, Bombax), mahogany (Swietenia), and Spanish cedar 
(Cedrela). An important tree of the hot lowlands is log-wood 
(Haematoxylon), an extremely valuable dye-wood belonging to 
the Leguminosae, a family with many representatives in the 
West Indies, as in other tropical countries. 

The Antilles are less rich in palms than the equatorial forests 
of the Amazon region, but nevertheless they play an important 
role in the flora of the larger islands, and include some of the hand- 
somest members of the order, such as the royal palm (Oreodoxa 
regia) and the still finer 0. oleracea, the "cabbage-palm" of Ja- 
maica. The beautiful Euterpe oleracea, so abundant in Guiana, 
occurs also in Jamaica but is much less common, and the same 
is true of the genus Bactris. Palmettoes and the spiny-stemmed 
"groo-groo" (Acrocomia), and fan-palms of the genus Thrinax. 
are characteristic genera, absent from the Amazonian forest 8. 

The upper rain-forest is characterized by an extraordinary 
development of ferns, and allied forms, Jamaica probably excel- 
ling in this particular any other known region of like extent. While 
the island has an area of only about 4,000 square miles, the great 
variety of soil, elevation and rainfall induces an unparalleled devel- 
opment of these plants, the total Dumber of species being nearly 
or quite 500. 




304 



THE NEOTROPICAL REGIONS :*<).■> 

In the Blue Mountains at elevations of 3,000-5,000 feel this 

fern-flora reaches its culmination, and ferns form the most conspic- 
uous features of the vegetation, ranging from stately tree-ferns, 
40-50 feet high, to tiny filmy-ferns looking more like delicate 
mosses than like ferns. Nowhere in the world can the student of 
these beautiful plants find a richer harvest. 

In addition to the true ferns, there are many lycopods or club- 
mosses, and occasionally one encounters in the stream-beds, 
groves of giant horse-tails (Equisetum giganteum), suggesting a 
forest of the coal period. 

The summits of the highest mountains have a sub-alpine flora, 
composed in part of the usual boreal genera. 



CHAPTER IX 
THE SOUTH TEMPERATE ZONE 

South Africa 

As the whole of Africa lies north of 35° south latitude, the Cape 
and the adjacent regions of South Africa all are within the warm 
temperate zone; and on account of the elevation of the central 
plateau, temperate conditions prevail over much of the area lying 
close to the Tropic of Capricorn, and even extending beyond it. 

As a whole, South Africa is a region of moderate or scanty rain- 
fall. The best watered regions are near the south and eastern 
coasts, while the west coast, except for a small part of the extreme 
southwest, including the Cape, is very arid and is continuous with 
the great desert regions of the Karroo and Kalahari, north of the 
Cape district. 

The southwest coast of the Cape has a rainfall of 60-70 cm. of 
which the greater part falls in the winter months: May-Septem- 
ber. The summer is nearly or quite rainless as in the Mediter- 
ranean region, California and southern Australia, and there is a 
marked superficial similarity in the vegetation, although it is 
composed for the most part of very different species. 

To the east of the Cape is a small strip (Knysna forest) where 
the mountains approach the coast, and this is the rainiest portion 
of the south coast. The mountains in places support a fairly 
heavy evergreen forest, but elsewhere in the Cape region the forests 
have been almost entirely destroyed, and they have been replaced 
by a dense growth of evergreen shrubs resembling the "macchie" 
of the Mediterranean countries, or the Calif ornian " chaparral." 

Following the coast eastward the rainfall becomes more evenly 
distributed through the year, and grasslands or savannas take the 
place of the evergreen forests and chaparral on the hills to the west. 
Further north, the summer rainfall exceeds that of the winter, and 
in the interior nearly all the rain falls in the summer months. This 
is much less favorable for vegetation, owing to the great loss of 
moisture due to evaporation. Because of the light rainfall, most 

306 



THE SOUTH TEMPERATE ZoXE 



307 



of South Africa, except near the coast, is destitute of proper 
forests, and is either grass-land and savannas, where there is suf- 
ficient rainfall, or a more or less complete desert , as in most of the 
great Kalahari and the Karroo. 

The Cape is famous for the beauty and variety of its flowers, 
many of which are familiar denizens of our gardens and conserva- 
tories. Such are the common calla lily, Pelargoniums, Gladioli, 
many species of Oxalis, Mesembryanthemum, Lobelia, and many 
others. The profusion of showy flowers adorning the sandy flats 



Bar 




Fig. 83. — Karroo vegetation near Beaufort West, Cape Colony. Carissa ferox (?), 
Euphorbia Mauretanica, Grewia cana, Lycium sp., Mesembryanthemum sp. 
Photo., Dr. W. A. Cannon. 



near Cape Town in September and October, is equalled only by the 
display in Western Australia under very similar conditions. 

In the chaparral on the mountain sides, are heaths of many 
kinds, and along the railways are millions of brilliant flowers of 
every shade of vivid color. Among these are many of the Iris 
family, especially species of Babiana, with blue, purple or lavender 
flowers. Others of the same family are species of Moraea, looking 
much like a true Iris, and with flowers of purple, yellow or bright 
orange; Pelargoniums of many species, calla oua (iazanias 

(Compositae), and giant sundews (Drosera), orchid-, Prot< 
(Proteaceae), and endless other brilliant flowers. 



308 



OUTLINE OF PLANT GEOGRAPHY 



A feature of the Cape flora is the abundance of bulbous and 
tuberous plants of the Iris family, which has a very large number 
of species. In addition to numerous species of Gladiolus, there 
are the less familiar Watsonias, with pink and scarlet flowers, 
white, red and yellow Ixia and Sparaxis, blue and purple Babianas, 
yellow, pink and white Romuleas. There are no proper species 
of Iris, but Moraea, which closely resembles it has many attractive 
species. Many of these beautiful Cape bulbs find a congenial 



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Va 



: 







Fig. S4. — Aloe ISchlechteri, north slope of kopje near Beaufort West. Photo., 

Dr. W. A. Cannon. 



home in California and Australia and are common ornaments of 
the gardens. 

The lily family and the Amaryllis family are abundantly repre- 
sented, and some are familiar in cultivation. The blue Agapanthus 
and pink Amaryllis bella-donna, which in late summer sends up its 
leafless stalks crowned with rosy flowers, are the best known of 
these. Less commonly seen in cultivation are species of Nerine and 
Brunsvigia. 

There are many beautiful ground orchids at the Cape, which in 
this respect, also, recalls West Australia. Among the characteristic 
genera are Satyrium, Disperis, Disa, Eulophia, and others. 

One is immediately struck by the abundance and beauty of the 
species of Oxalis, white, yellow, pink and crimson, which occur in 



THE SOUTH TEMPERATE ZONE 309 

great profusion. One of these, the yellow 0. cernua, is a rampant 
grower which has become a troublesome weed in parts of the 
Mediterranean and Australia, where it was introduced as an 
ornamental plant. 

Very abundant and conspicuous are the many species of Mes- 
embryanthemum (''ice-plant," etc.) which are so extensively 
planted in California and other warm temperate countries. 

Giant sundews with pink flowers the size of a half dollar, are 





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Fig. 85. — Vegetation of very dry central Karoo. Mesembryanthemum calamiforme, 
Cotyledon hemisphaerica (?). Photo., Dr. W . A. Cannon. 

common, and again remind one of West Australia, where this genus 
is also extraordinarily developed. 

The Compositae, as in most other countries, are much in 
evidence, and include very showy species many of which have 
been introduced into cultivation. Especially showy are the many 
species of Gazania, with white, yellow or orange flowers. Much 
like these are Dimorphotheca and Arctotis, also sometimes seen 
in cultivation. 

Leguminosae are common, and include some showy species, 
e. g., Sutherlandia frutescens, but they are much less abundant 
than in Australia. 

Grasses and sedges are not specially abundant in the open 
places where so many showy flowers are found, but neverthel< 



310 OUTLINE OF PLANT GEOGRAPHY 

there are numerous species. Much resembling sedges are the 
Restionaceae, a family especially characteristic of the Cape region, 
but also found in Australia. Elsewhere the family is almost un- 
known. 

The thickets covering the hillsides are composed of a great 
variety of shrubs and small trees. Some of these belong to familiar 
genera, like the evergreen sumacs (Rhus) ; but the greater number 
belong to genera quite unknown in the northern hemisphere. 
Among the most abundant of these chaparral shrubs are many 
species of Protea, Leucadendron, and other members of the family 
Proteaceae, whose headquarters are South Africa and Australia. 

Some species of Protea are very showy, the big heads of flowers 
being enclosed in broad scales, pink or purple in color, the whole 
inflorescence reminding one of an artichoke; indeed one of the 
finest species, P. cynaroides emphasizes this fact. The species of 
Leucadendron may become small trees, and while the flowers are 
less conspicuous than those of Protea, the broad silvery leaves of 
the best known species, L. argenteum, the " silver-tree " of Table 
Mountain, make it very ornamental, and it is not infrequently 
seen in cultivation in California and elsewhere. 

A curious leafless twiner, Cassytha sp. is often seen climbing 
over the shrubs. While this reminds one of the common dodder, 
it is quite unrelated to the latter, but belongs to the laurel family. 
The genus is wide-spread through the warmer parts of the world. 

Among the most attractive of the Cape flowers, are the many 
true heaths (Erica), developed in South Africa to an extraordinary 
degree, the Cape flora alone having no less than 350 species. They 
are most abundant on its hills and in mountainous districts, and 
in the spring one may see great bunches of these beautiful flowers 
offered for sale in the streets of Cape Town, indeed one fears that 
some of the rarer species are threatened with extinction. 

The writer, unfortunately, was unable to make the ascent of 
Table Mountain, which is famous for its beautiful and interesting 
vegetation. 

The distinguished German botanist, Professor Engler, 1 has given 
an interesting sketch of a trip made at the time of the writer's 
visit to South Africa. Engler's account, however, is confined to 

1 Engler, A., Die Pflanzenwelt Africas, p. 494, Die Vegetation der Erde, 
IX, 1910. 



THE SOUTH TEMPERATE ZONE 311 

the region below 2,000 feet. He notes a fine grove of silver-tn 
and compares the thick growth of evergreen shrubs to the "mao- 
chie of Corsica and Algiers," but notes that this formation at the 
Cape is much richer in species than the corresponding formation 
in the Mediterranean regions, and that there were more species 
with showy flowers. Especially conspicuous were species of 
Podalyria (Leguminosae) Polygala (milk-wort), sumacs, and many 
others. 

White, pink and scarlet heaths were abundant and among the 
rocks were stone-crops (Crassula, Cotyledon, Rochea) with fleshy 
leaves and showy pink or scarlet flowers. 

The blue African lily (Agapanthus) is also a common plant of 
this region, as well as many of the showy Iridaceae already men- 
tioned. 

The fine Protect cynaroides belongs to Table Mountain also, and 
one of the handsomest orchids, Disa grandiflora, with large scarlet 
flowers. 

Among the common Compositae are species of Helichrysum, 
a genus also abundant in Australia, and furnishing some of the 
showiest of the garden "everlastings." Engler calls special 
attention to two of the chaparral shrubs: viz., Cutwnia Co pens is 
and Grubbia rosmarinifolia. The former is a monotypic speci' 
belonging to the essentially southern family Cunnoniaceae. 
Grubbia represents a family, Grubbiaceae, confined to the Cape 
region. 

The Cape is not rich in ferns, as the long diy summer is not 
favorable to most of them. Nevertheless there are some interesting 
species in the sheltered gullies, or rock crevices. One of the most 
notable is Todea barbara, a very handsome fern which also occurs 
in Australasia. In some of the gulches of Table Mountain, a 
small tree-fern, Hemitelia Capensis, occurs, and a single small 
filmy-fern (Hymenophyllum) was noted by Engler. At Muizen- 
berg, near Cape Town, the writer collected specimens of the inter- 
esting Gleichenia polypodioides belonging to a family having no 
representatives in Europe or the United States, but common in 
the warm temperate regions of the southern hemisphere. 

Just as many plants native to the Cape have been introduc 
into other countries, so one may see in Cape Town a great many 
trees, shrubs, and herbaceous plants brought from abroad. One 




Plate XXXIX. — Hillside vegetation near Durban, Natal. Arborescent 

Euphorbias are conspicuous. 



312 



THE SOUTH TEMPERATE ZONE 313 

is at once struck by the magnificent European oaks and the stately 
stone pines from the Mediterranean which are perfectly at home 
and completely naturalized. Two Californian conifers arc ex- 
tensively planted, the Monterey pine (Pinus radiata) and the 
Monterey cypress (Cupressus macrocarpa). These two trees are 
very restricted in their natural range on the coast of central 
California, but are easily grown and are now extensively planted in 
many warm temperate countries. 

Australian gums, wattles (Acacia), and Casuarinas are also 
frequently planted, the Acacias being grown extensively for their 
bark, which is of great value for tanning. Hakea suaveolens, one 
of the Australian Proteaceae, has escaped from cultivation in some 
places and become quite naturalized. 

All the fruits of the warm temperate zone flourish at the Cape. 
Peaches, apricots, figs, oranges and grapes, are extensively grown, 
the latter yielding wine of great excellence. 

It is supposed that much of the Cape region was originally 
forested, but at present almost no forest is left, and only in a few 
mountainous districts can one see the remnants of the original 
forest. The most important trees are species of Podocarpus; 
P. latifolia, and P. elongata are said to reach a gigantic size. Two 
species of Callitris, small trees resembling junipers or cypresses 
are the only representatives of the true conifers. 

In the low wet ground the common calla-lily is very abundant, 
and on the ponds are white and blue water-lilies, and various other 
aquatics, some of the common pond-weed types, rushes, and sedges, 
but others peculiar to the region, like the curious Aponogeton dis- 
tachya, whose forked clusters of white flowers at once attract 
attention. 

Natal 

On the east coast of Africa, the transition from the strictly 
tropical to the temperate regions is a very gradual one. Durban, 
the port of Natal, in lat. 30°, has a sub-tropical climate suited to 
the growth of many tropical products: sugar, bananas, pineapples, 
etc., and in the attractive botanical gardens of the town, one may 
see coco-palms, royal palms, bamboos, and many gorgeous tropical 
trees and shrubs growing luxuriantly. 

Fronting the Indian Ocean, the climate is warm and humid, 



314 OUTLINE OF PLANT GEOGRAPHY 

with a pretty heavy rainfall, so that the coastal vegetation is 
luxuriant, and made up to a great extent of species related to those 
of the tropical regions to the north. Such are the wild date-palms 
{Phoenix rcdinata) and another palm, Hyphaene crinita, several 
species of Ficus, the banana-like Strelitzias and many others. 

In the valleys between the coastal hills is a forest formation of 
moderate sized trees, mostly of tropical affinities like the species 
of Ficus, the "water-boom" (Sijzygium cordata), of the Myrta- 
ceae; Albizzia, Mimusops, Strychnos, Combretum, etc. 

Along the coast, in places, are mangrove swamps, in which the 
principal species is the white mangrove (Avicennia officinalis). 
Back of the mangroves, the wide-spread yellow tree-Hibiscus 
(H. tiliaceus) and a species of Barringtonia, a handsome genus of 
trees characteristic of the strand-floras of the eastern tropics. 

Many handsome evergreen shrubs form the undergrowth of the 
forest; among them the writer noted the brilliant scarlet flowers of 
a trumpet creeper {Tecoma Capensis), the fragrant white flowers 
of the " Natal plum" (Carissasp.), and several species of 
Gardenia. 

Adding much to the tropical aspect of the jungle were great 
masses of the stately Strelitzia Augusta, much resembling the 
traveller's tree (Ravenala) of Madagascar. Lianas are conspic- 
uous, among them an evergreen grapevine (Vitis Capensis), growing 
to the tops of the trees, and many less rampant vines— cucurbits, 
morning glories, and some curious asclepiads scrambled over the 
shrubs and smaller trees. 

A very splendid sight was the " Kaffir-boom," Erythrina Caffra, 
the leafless branches bearing clusters of vermilion flowers. 

Engler l reports two epiphytic orchids, Angraecum sp. and 
Polystachya sp. as common in this region, but these were not seen 
by the writer. 

In the sheltered valleys two tree-ferns, Cyathea Dregii and 
Hemitelia Capensis, occur, and also Todea barbara. 

The floral display in Natal is less remarkable than in the Cape 
region, but there are nevertheless many very beautiful species. 
Near Durban are " flats" like those around Cape Town, and in 
these are many showy flowers, especially Compositae, e. g., Ga- 
zania, Senecio, Gerbera, everlastings; Lobelia, sundews, and many 

1 Loc cit., p. 411. 










u 



H 
H 

•< 
J 



315 



316 OUTLINE OF PLANT GEOGRAPHY 

others. The Liliaceae and Iridaceae, are perhaps not so numer- 
ous as at the Cape, but they include some very showy species of 
Kniphofia, Anemotheca, Tritonia and others. 

While most of the trees belong to tropical genera, there are a 
few related to northern ones, such as species of sumac (Rhus), 
Celtis, and Vernonia, a shrubby composite of the same genus as 
the iron weed of the eastern United States. 

On the drier hills are xerophytic forms, related to those of the 
arid parts of Africa. Especially conspicuous are the great can- 
delabra Euphorbias (E. grandidens), recalling the giant Cacti of 
Arizona and Mexico. Aloes, some of them almost trees, much 
resemble in appearance the century-plants of the American south- 
west. The flowers of some of the Aloes are extremely showy, great 
spikes of flaming scarlet or orange bloom. Another showy flower 
of this region is Haemanthus, which sends up from a bulb a short 
stalk crowned by a dense head of scarlet flowers, with a fringe of 
long stamens. Of the Liliaceae with less showy flowers, are many 
species of Asparagus, one of which, A. plumosus, is common in 
cultivation under the name " Asparagus fern." 

Among the most interesting botanical features of Natal are the 
cycads. Two genera are found, Encephalartos, with several spe- 
cies, and Stangeria paradoxa, the most fern-like of all the cycads, 
and when first discovered, mistaken for a genuine fern. 

The sub-tropical type of vegetation in Natal reaches from the 
coast to about 1,500 feet elevation, above which, is a temperate 
belt extending to the foot of the Drakensberg, the mountains 
separating Natal from the Orange State and Transvaal. 

The railway from the coast ascends through a fertile and 
picturesque country, which in places is broken by bold ravines or 
"kloofs," in which there is a fine growth of timber. Plantations of 
Eucalyptus and Acacia are frequent, these Australian immigrants 
appearing to be as much at home in Natal as they are in California. 
Peach trees apparently have become naturalized in many places 
in the higher parts of Natal, and in the spring (October) were in full 
flower, presenting a beautiful sight. A stop at Ladysmith, gave 
opportunity to examine the very typical formation of this region, 
flat-topped " Kopjes" rising from the plateau. The slopes of these 
rugged hills were clothed with a variety of more or less xerophytic 
plants, among which the Aloes were conspicuous, being in full- 



Till: SOUTH TEMPERATE ZONE 317 

bloom, the great candelabra flower spikes a blaze of orange and 

scarlet, a truly splendid sight. 

The Drakensberg has peaks 10,000-11,000 feet high, the loftt 
mountains in Africa south of Kilimanjaro, and in winter, .-now- 
clad. The valleys of the streams flowing to the sea are often deep 
and abrupt, and are clothed with heavy forest, but the open coun- 
try is mostly grass-land or savannas. 

Among the most valuable timber-trees are Podocarpus and 
mountain cypress (Callitris cupressoides) . 




*& ■£*■ 










Fig. 86.— High Veldt, Transvaal. 

Passing the barrier of the Drakensberg, one enters the extensive 
table land of the Orange State and Transvaal, the "High Veldt" 
of the Boers, a plateau with an average elevation of 4,000-5,000 
feet. The mountains intercept much of the moisture from the 
Indian Ocean and the climate is a relatively dry one. with an 
annual precipitation of 20-25 inches (53 64 cm.). As the rain falls 
mostly in the hot weather, and often in violent thunder storms, 
much moisture is losl by evaporation, and the country for the 
most part, is treeless, except in sheltered places or along the 
streams. 



318 OUTLINE OF PLANT GEOGRAPHY 

The high veldt reminds one of our own western plains, but the 
climate is much milder in winter. About Johannesburg one may 
see orchards of oranges and other vegetation which show that 
the cold is never severe, a great contrast to the arctic winters of 
Wyoming and Montana. 

The writer's acquaintance with this region is confined to a brief 
visit in the early spring (September) before the summer rains had 
started the dormant vegetation, and the monotonous veldt was an 
almost unbroken expanse of dead grass, with only here and there 
an occasional low bush or stunted tree. 

In summer there is a vigorous growth of tall grasses which 
furnished feed for the hosts of antelopes and other big game that 
once roamed these great natural pastures, much like the buffalo and 
antelopes of our western plains. 

According to Engler x the predominant grass is Antistheria 
imberbis associated with species of Andropogon, Panicum and 
several others. The bulbous plants, so abundant in the Cape 
region and Natal, are much less common, but on the slopes of the 
hills and in the moist depressions, are showy species of Crinum, 
Gladiolus, Ornithogalum and others. Dicotyledonous herbs are 
abundant and include representatives of many families. 2 While 
many of these belong to wide-spread genera, like Lepidium, 
Cassia, Indigofera, Polygala, Heliotropium, Lobelia, etc., a large 
number represent genera unknown in the northern hemisphere. 

On the rocky slopes of the kopjes, one may see such conspicuous 
plants as the flesr^-leaved Aloes and Euphorbias, stone-crops, and 
the showy Mesembryanthemums. 

The most abundant trees of the veldt are the thorny Acacias, 
especially the " Kameel-dorn " (Acacia giraffae) which grows 
mainty along the stream-banks together with several other species 
of small trees, among which is an olive (Olea chrysophylla) , sumacs, 
a willow (Salix Capensis) and several others. 

While the high veldt is mostly a pastoral region, one may also 
see orchards of oranges and peaches, the latter in full bloom in 
September and presenting a beautiful sight, especially when, as 
was often the case, they were associated with weeping willows 
just bursting into leaf, a tree which is very often seen about the 
farms in the neighborhood of Johannesburg and Pretoria. 

1 hoc. cit., p. 458. 2 Engler, loc. cit. 



THE SOUTH TEMPERATE ZONE 319 

Successful experiments have been carried out on field and orchard 
crops in this region where climatic conditions are comparable to 

those of California, and the orchards are cultivated in much the 
same way. Maize is a staple crop in South Africa, and in pla< 
alfalfa is also proving profitable. 

North of Johannesburg is Pretoria, and not far away from the 
latter is a range of low mountains, the Magalisberg, a region with 
a flora quite different from that of the open high veldt. This 
marks the beginning of the " bush-veldt," a savanna region with 
an open growth of trees, sometimes becoming a continuous thin 
dry forest. 

The trees of the bush-veldt are mostly deciduous, and in Sep- 
tember looked much like the leafless winter forests of the north. 
There is, however, a considerable number of evergreen species, 
notably the figs, which remind one how near this region is to the 
tropics. 

Near Pretoria a small stream breaks through the range of hills, 
and along its banks is a thin growth of small trees and shrubs. 
Among these were noted two sumacs, a hackberry (Celtis) jusl 
unfolding its leaves, and several unfamiliar species. Close to the 
water was a willow, and tall reeds (Phragmites communis) and 
sedges grew in the moist sand. 

In the clefts of the rocks were various succulents, Aloes and 
stone-crops; and a club-moss (Selaginella Dregei) not unlike the 
American S. rupestris, was quite common. Two xerophytic fern-. 
Notochlaena lanuginosa and Pdlaea calomelanos, were also noted. 
Another interesting fern was Mohria Caffrorum, of the family 
Schizaeaceae. 

Of the various shrubs growing on the rocky banks, one in partic- 
ular attracted attention by its .profusion of pretty white flower-. 
This shrub, Dombeya Natalensis, is occasionally grown in California. 

To the northwest of the Magalisburg, the bush-veldt is continued 
and the trees sometimes reach quite respectable size, indeed one 
of these, a banyan fig, may become quite an imposing tree. A 
specially fine example of this species (Ficus cordala) known locally 
as the "wonder-boom," is one of the sights of this region. The 
great dome of foliage was said to be 1G0 feet in diameter. Other 
trees and shrubs of this neighborhood noted were species of Acacia, 
the scarlet-flowered Erythrina Caffra, Strychnos pungens, Bwrhea 



320 OUTLINE OF PLANT GEOGRAPHY 

Africana, and a poisonous plant, Dichapetalum toxicarium belong- 
ing to the predominantly African family Dichapetalaceae. 

West of Transvaal and Rhodesia the precipitation falls off, 
and along the Atlantic coast true desert conditions prevail. The 
bush-veldt gives place to open formations with a fairly extensive 
vegetation in the less arid portions, but over much of the region 
the vegetation is extremely scanty. This great arid region is the 
Kalahari Desert, and occupies most of the table land west of the 
Transvaal and Rhodesia. The whole region has a scanty rainfall, 
in some places an annual precipitation of only about four inches. 

At the extreme north there are a good many species of tropical 
origin, but on the whole the species are the same as those of the 
adjacent regions, and there are few peculiar to the Kalahari. 
The grasses are thin and scattered, and there are scrubby bushes 
and stunted trees in many places, the commonest being the wide- 
spread Acacia giraffae. 

Among the herbaceous plants of the Kalahari are several of the 
melon family, including, according to Engler, true water melons 
(Citrullus vulgaris), which are highly prized by man and beast. 

Travelling southward from the Orange State one descends from 
the high table land toward the lower arid region of the Karroo. 
This has a very dry climate, sometimes almost rainless for periods 
of a year or more. When, however, the rains come, there is a 
surprising amount of vegetation developed, many species having 
underground tubers or bulbs which may remain dormant indefi- 
nitely, only waiting for sufficient moisture to put forth leaves and 
flowers. Shrubs and trees quickly unfold fresh green leaves which 
are destined soon to wither away. 

Trees are scarce, but there are many low shrubs scattered over 
the landscape, which is not unlike that of parts of Nevada or Ari- 
zona. As in the southern American deserts, there is a marked 
development of succulents, but the place of the American Cacti 
and Agaves is taken by cactus-like Euphorbias and Aloes. In 
some places, however, true Cacti (Opuntia spp.) may be seen, but 
these prickly-pears, although completely naturalized, are escapes 
from cultivation. 

As in the Cape region, there are many showy species of Mesem- 
bryanthemum, and the curious Stapelias, members of the milk- 
weed family are characteristic of the Karroo. The latter have 



THE SOUTH TEMPERATE ZONE 321 

fleshy leaves and dull purplish flowers, with a most evil scent of 
carrion, which attract flies and other insects that doubtless play 
their part in pollination of the flowers. 

The writer travelled through this region in September, 1905, 
a season of unusually abundant rains, so that the Karroo was seen 
in its most attractive aspect. While the low bushes, looking like 
sage-brush were perhaps the most obvious feature of the landscape, 
there were also many bright flowers, the most conspicuous a 
pink Mesembryanthemum which occurred in large masses, and in 
the distance reminded one of the heather on Scottish moorlands. 1 

The railway through the Karroo ascends to a height of about 
3,500 feet (1,150 m.) and then descends through picturesque scenery 
to the beautiful valley of the Hexe River, one of the most attrac- 
tive regions in South Africa. The vegetation of the Hexe valley 
is a combination of that of the Karoo and the true Cape flora. 
In September, the height of the spring season, the wonderful 
Cape flora was in its glory, and is unsurpassed by anything the 
writer has seen unless, perhaps, the somewhat similar floral dis- 
play in West Australia. 

On the rocky hillsides were masses of beautiful heaths and other 
showy shrubs, and along the railway were millions of exquisite 
flowers of every shade and color: white, yellow, pink, vivid orange, 
scarlet, blue and purple. Particularly abundant were the Babian 
beautiful plants of the Iris family, sometimes seen in Calfornian 
gardens. These have all shades of blue, purple and crimson, 
and in mass are extraordinarily effective. This region is also the 
home of many species of Freesia, Ixia, Sparaxis and Gladiolus, 
all garden favorites. 

Australasia 

Australia and New Zealand, isolated as they are, show a very 
high degree of endemism both among plants and animals. The 
outlying islands share in this, and the great island of Papua, or 
New Guinea, and the adjacent islands to the west, are to a cer- 
tain extent Australian in their vegetation, and connect the Austral- 
asian floras with the more strictly Malayan vegetation of the 
large western islands of the Archipelago. 

1 For details of the flora of the Karroo, Engler, loc. cit., pp. 1 • i ^ 177. 

Cannon, W. A., Carnegie Institution of Washington, Publication 354; 1924. 




Plate XLI. — Bunya pine (Araucaria Bidwillii), Queensland Australia. 



322 



THE SOUTH TKMI'EKATi; ZONK 323 

Australia 

Australia comprises much the greater part of Australasia, 
equalling in area the whole United States exclusive of Alaska. 
The northern portion lies within the tropics, while its southern- 
most part corresponds in latitude to New York City. The climate, 
therefore, ranges from a true tropical one at the north, to a warm 
temperate one in the south, comparable to that of the Mediter- 
ranean, or southern California. 

Australia is lacking in high mountains and there is a dearth of 
large rivers and lakes, and much of the country is occupied by 
monotonous plains of great extent, and largely arid. The highest 
elevations are near the eastern coast, where a succession of high- 
lands and mountain ranges extends from the York Peninsula to 
Victoria and Tasmania. Along the coast of North Queensland are 
some definite mountain ranges, but for the most part the high- 
land is a plateau sloping westward to the interior with more or less 
definite escarpments near the coast. These escarpments are some- 
times deeply indented by abrupt gorges, such as may be seen in the 
Blue Mountains west of Sydney. The highest point in Australia, 
Mt. Kosciusco (7,300 ft.) is in New South Wales near the Victoria 
border. The eastern highlands and the coastal strip, have, as a 
rule, a good rainfall, but there are no large rivers. The heaviest 
rainfall in Australia is in the coastal region of North Queensland, 
at the foot of the Bellenden-Ker range. At one station, Babinda, 
visited by the writer, the annual precipitation sometimes exceeds 
200 inches. 

Inland, however, the rainfall diminishes rapidly, and a third of 
the continent, some 1,000,000 square miles, is said to receive 1. 38 
than ten inches annually, while another third has less t han t unity. 
This means that a large part of Australia must be considered as 
too arid for most agricultural purposes except under irrigation. 
Vast areas, however, are adapted to grazing, and sheep raising is 
at present the most important industry of the commonwealth. 
There is a more or less pronounced wet and dry season in most 
parts of Australia. In the south, the rains come mostly in the 
winter months — May-September, — while at the north, summer Is 
the rainiest period. 

The rain-forests of North Queensland contain many wide- 




Plate XLII. — Eucalyptus forest, Victoria, Australia. 



324 



THE SOUTH TEMPERATE ZONE 

spread Malayan types, like the figs, Bcrew-pines, palm-, arums, 
and many epiphytic ferns and orchids. The Malayan character 
of the flora is especially marked in the northernmost region, the 
York Peninsula, which has many genera absent from the rest of 
Australia, like the pitcher plants (Nepenthes), and palms of the 
genera Caryota, Borassus and Areca. 

As one travels southward, beyond the tropics, one still meet 
considerable number of the Malayan rain-forest species where the 
conditions of soil and moisture are favorable, but these gradually 
disappear, and are replaced by more strictly Australian typ< 9. 

Among the most notable of Australian trees arc the conifers of 
the genus Araucaria. The finest is A. Bidwittii, the "Bunya- 
pine," of southeastern Queensland, where in one district it form- 
forests of considerable extent. A more wide-spread species is .1 
Cunninghamii, which is very abundant along parts of the Queens- 
land coast, forming pure stands, like some of the pines and spruces 
of the Pacific coast of North America. 

Other species occur in some of the adjacent islands, New Cale- 
donia and Norfolk Island. The Norfolk Island pine (A. excel 
is the most familiar. Two South American species are the only 
others known to science. 

The coastal region of New South Wales shows much the same 
type of vegetation as southern Queensland; but the tropical types 
become less abundant and there is an increasing number of such 
true Australian genera as Acacia and Eucalyptus. The rain-forest , 
however, still has a decidedly tropical aspect, with tall palms, 
tree-ferns, and lianas. 

Away from the coast, and wherever the soil is poor, the dense 
rain-forest is replaced by open Eucalpytus-foresl with an under- 
growth composed of a great variety of smaller trees and shrubs, 
all more or less decidedly xerophytic in character. Herbaceous 
plants are not very abundant, but there are a good many grass - 
and sedges, and numerous bulbous and tuberous species including 
many showy orchids and Liliaceae, which with the profusion of 
showy flowered shrubs, make a magnificent show in the spring. 
Many species of Eucalyptus, Leptospermum, Melaleuca. ( al- 
listemon, often seen in cultivation, as well as other- [ess familiar, 
represent the myrtle family; while the Leguminosae are even 
more abundant, and comprise a host of showy species. Of th< 










X>. 



o 







Plate XLIII. — Giant Eucalyptus (E. regnans), Victoria, Australia. 



326 



THE SOUTH TEMPERATE ZONE 327 

Acacia leads in number of species, but the pea-family is also ex- 
tremely abundant. About Sydney several species of Boronia and 
Eriostemon (Rutaceae), are common and beautiful Bhrubs, and 

many other unfamiliar flowers abound. 

As elsewhere in Australia, New South Wales has many Pro- 
teaceae, a family which reaches its maximum development in 
Australia. The commonest genera are Grevillea, Banksia and 
Hakea. To this family belongs also the "Waratah " (Telapea 
speciosissima) one of the most gorgeous of Australian flowers, 
whose magnificent clusters of scarlet are the pride of New South 




.Uf 



Fig. 87. — Desert vegetation, Transcontinental Railway. Australia. 

Wales. Another very splendid plant, common near Sydney is 
the giant torch-lily {Doryanlhes exceha) which bears aloft on a 
stout stem, 10-15 feet high, a huge cluster of immense scarlet lilii 

The southeastern part of Australia is occupied by Victoria, 
the smallest stale in the commonwealth, being about the size of 
Kansas. Much of Victoria has a temperate climate, adapted to 
the staple crops of the temperate zones, and better suited to Euro- 
pean settlers than the hotter parts of Australia. 

Its smaller size and more uniform climate resull in a lesser 
variety of vegetation than in the larger states; but in the well 
watered mountains of the east are found magnificent forests of 
giant gums (Eucalyptus regnans), dose rivals in height of the 



328 



OUTLINE OF PLANT GEOGRAPHY 



Californian redwoods. The forests of giant gums, with their un- 
dergrowth of tree-ferns and other luxuriant vegetation, are among 
the finest in the world. 

Travelling overland from Victoria to the west coast of Australia, 
one traverses, for the most part a region of deserts, or dry steppes 
comparable to those of Arizona or southern California. Extensive 
tracts show only a sparse growth of salt-bush (Atriplex, Kochia, 
etc.) reminding one of the sage-brush desert of Nevada and Utah; 
but for the most part there is a growth of stunted trees and shrubs, 



•••■-. • ■ 




Fig. 88. — Sandy desert near Oodnadatta, South Australia. Eucalyptus sp. Photo., 

Dr. W. A. Cannon. 

with scattered bunch-grasses, and sometimes a few showy her- 
baceous plants. 

The commonest trees are gums of several species, the shrubby 
ones known locally as "Mallee." Other common trees noted were 
species of Casuarina, whose thin leafless twigs simulate pine- 
needles, and the tree suggests a scrubby straggling pine. Cas- 
uarina is essentially an Australian genus, although a few species, 
especially as strand-forms, reach the western Malayan region. 

Of the shrubs, several species of Acacia and a sandal-wood 
(Santalum), may be mentioned. In October, the golden flowers 
of the wattles relieved the monotony of the prevailing dull green 



THE SOUTH TEMPERATE ZONE 



329 



of the foliage of most of the desert shrubs. Showy flowers wen- n< »t 
abundant, but here and there masses of pink and white everla 
ings were seen, and the splendid scarlet flowered "Sturt-pea," 
(Clianthus Dampieri), is abundant in some localities. 

As the west coast is approached the country becomes less arid, 
and presently the increasing moisture is evident in the more luxuri- 
ant vegetation and the profusion of showy flowers which in the 
spring adorn the country. The train passes through a veritable 
garden of brilliant bloom. The variety and beauty of this floral 




F IG# 89.— Coastal vegetation, Perth, West Australia. 

calophylla), Banksia grandis. 



Red gum (Eucalyptus 



show must be seen to be appreciated. While some of the flowers, 
especially the many Papilionaceae and lilies, seem more or less 
familiar, most of them are quite strange to the northern botanist, 
many belonging to families entirely wanting in the northern hemi- 
sphere. The family Goodeniaceae includes many species of yell* m 
Goodenia, and blue Dampiera and Leschenaultia, one of the latter, 
L. formosa of a blue so magnificent, that once seen, can never be 

forgotten. 

Ground orchids are remarkably abundant in West Australia, 
mostly characteristic Australian genera, e. g., Caladenia, Diuris, 
Thelymitra, and others quite si range to the European or American 
botanist. Many of these are very beautiful. Another striking 



330 



OUTLINE OF PLANT GEOGRAPHY 



feature of this region are the many species of sundews which 
abound in the sandy moorlands, some of them slender, half -climb- 
ing plants four or five feet high, with pink flowers like small single 
roses, while others are tiny rosettes of leaves lying close to the 
ground. Yellow Hibbertias (Dilleniaceae), several pretty Lil- 
iaceae (e. g., Thysonotus, Burchardia), and species of Pattersonia, 
of the Iris family; Boronias and many species of the curious "trig- 




A B 

Fig. 90. — A. Wild flowers, Perth. At extreme left, "Kangaroo paws" (Anigozan- 

thus Manglesii); B. Banksia grandis. 

ger-flowers," Candollea, are common and characteristic. Among 
the many strange and showy flowers peculiar to West Australia 
none are more remarkable than the " Kangaroo-paws" of the genus 
Anigozanthus (Amaryllidaceae). These flowers show the most 
bizarre coloring— green and scarlet, yellow and black, red and 
yellow, or pure green. 

Besides the many species of Eucalyptus, Acacia and Casuarina, 
the smaller trees and shrubs include many Proteaceae, of which 
Grevillea, Banksia and Hakea are the most abundant; Myrtaceae, 



THE SOUTH TEMPERATE ZONE 



331 



with numerous species of Leptospermum, Melaleuca and Cal- 
listemon, and many others less common. 

The only gymnosperm seen by the writer in Western Australia 
was a cycad, Macrozamia Fraseri, which was very common and 
a serious pest, as animals are often poisoned by eating the young 
foliage in times of drought. 

Especially abundant in West Australia, but found also in the 







-< 7" 




*■{*$- 



->. 




Fig. 91. — Cycad {Macrozamia Fraseri), West Australia. Phuto., courtesy of 

Mr. C. E. Lane-Poole. 

other states, are the " grass-trees " (Xanthorrhoca), striking if 
not beautiful features of the vegetation. The larger species have 
a stout trunk and recall in habit the tree- Yuccas of Southern 
California and Mexico; but the numerous drooping leaves are 
much more slender and the innumerable flowers, borne on a tall 
club-like spike, are insignificant and quite lacking in the beauty of 
the Yucca. 

Throughout the less arid parts of West Australia, the spring 
display of flowers from August to November, is quite unrivalled 
elsewhere, and perhaps culminates in the Albany district, to which 
are confined many species, among them the curious pitcher plant, 



332 OUTLINE OF PLANT GEOGRAPHY 

(Cephalotus). In variety and beauty, the flowers of the Albany 
district surpass anything the writer has ever seen. 

The visitor to Australia is at once impressed by the dominance 
of the gum forests. Although the prevailing dry open forest is 
very monotonous, one must remember that some of the species of 
Eucalyptus are among the stateliest and most striking of trees. 
The Karri (E. diversicolor) of West Australia, and the giant gums 
of Victoria, as well as other species of the moister regions of New 
South Wales and Queensland, are among the finest of all trees. 
Many species show beautiful golden or ruddy tints in the young 
leaves, contrasting beautifully with the gray-green of the adult 
foliage, and the flowers are often very showy, especially in some 
of the species of West Australia. The best known of these is the 
scarlet flowered E. fici folia, which is often cultivated. 

The Myrtaceae, which include Eucalyptus, number about 800 
Australian species, among which are other fine trees, related to 
Eucalyptus. Among these are Tristanea, Angophora and Syn- 
carpia. In the moister and warmer regions, are also found species 
of Myrtus and Eugenia, both wide-spread genera. 

Even more numerous than the Myrtaceae are the Leguminosae, 
with over 1,000 species. First in importance is Acacia, with over 
400 species, everywhere abundant, and ranging from tiny shrubs, 
a few inches high, to trees of large size. They are generally known 
as " wattle," and the masses of golden flowers of many species are 
a feature of the spring landscape all over Australia. Many of them 
are favorities in the gardens of California and the Riviera, where 
they often go by the name of " mimosa." 

The pea family, or Papilionaceae, contributes a host of showy 
flowers to the spring show. Their colors are extremely brilliant — 
pink, scarlet, orange, yellow, blue and purple, and the flowers 
are borne in great profusion. Many of the genera, e. g., Chorizema, 
Gastrolobium, Jacksonia, etc., are strictly Australian, but only 
a few of them are in cultivation. 

The Proteaceae, which have no representatives in the United 
States, and are almost entirely wanting north of the equator, 
are third in number in the Australian flora. They are mostly 
shrubs, but some are trees of considerable size, the latter 
most abundant in the rain-forests of Queensland and New 
South Wales. Of these, the silk-oak (Grevillea robusta) is often 




Plate XLIV.— 



Grass-trees (X anthorrhoea Preterit), West Australia. 

courtesy of Mr. C. E. Lane-Poole. 



Photo., 



333 



334 OUTLINE OF PLANT GEOGRAPHY 

cultivated, and less frequently others are seen, e. g., Stenocarpus, 
Macadamia. 

Few Australian trees are more characteristic than some species 
of Banksia, whose stiff serrate leaves, and big oblong heads of 
flowers are very striking. Except for a few trees of the northern 
rain-forests, most of the Proteaceae are xerophytic in habit. 

Other characteristic Australian families with few or no repre- 
sentatives elsewhere are the Tremandraceae, Goodeniaceae, 
( andolleaceae and Casuarinaceae. 

The gymnosperms of Australia, apart from the cycads, Kauri, 
and Araucarias, are mostly of the yew family, the most important 
being species of Podocarpus. Most nearly related to the northern 
conifers are several species of Callitris, much resembling cypresses. 

Tasmania has a number of peculiar Taxaceae, absent from the 
mainland, but also found in New Zealand. The most important 
of these are Dacrydium and Phyllocladus. 

Ferns and their relatives are scarce, or wanting in much of 
Australia, owing to the prevalence of arid or semi-arid conditions. 
Where there is sufficient moisture, however, as in the mountain 
forests of Victoria, New South Wales and Tasmania, they are 
abundant and luxuriant, and form an important element of the 
vegetation. 

Tree-ferns are abundant in these regions, especially species of 
Alsophila and Dicksonia, and in the wetter districts, filmy- 
ferns, and other epiphytic species abound. Among these the 
extraordinary stag-horn ferns (Platycerium), are common and 
conspicuous. 

Club-mosses (Lycopodineae) and the curious Psilotum and 
Tmesipteris, are sometimes seen, and many interesting liverworts 
and mosses may be found by the student of these plants. 

Tasmania, unlike most of the Australian mainland, is extremely 
mountainous, and in the west especially, has a heavy rainfall. 
Both in topography and climate it has much in common with New 
Zealand, and like the latter there is an important element in the 
flora closely related to that of Patagonia and the Chilean Andes. 
Some of these " Fuegian " plants occur also in southern Victoria and 
the higher mountains of New South Wales and Queensland. The 
most important of the Fuegian types are the antarctic beeches (No- 
thofagus), the sole representatives of the oak family in Australia. 




Plate XLV. — Interior of Kauri forest, North Island, New Zealand. 



335 



336 OUTLINE OF PLANT GEOGRAPHY 

New Zealand 

New Zealand, lying over 1000 miles from Australia, and like it, 
completely isolated, consists of two main islands of about equal 
size, and a number of small outlying ones. The two principal 
islands lie between 34° and 47° S. lat., and the total area is a little 
more than 100,000 square miles. 

New Zealand presents a strong contrast to Australia, both in 
topography and climate. Its relatively small area results in a 
decidedly insular climate with very much less range of precipita- 
tion and temperature than is found in continental Australia. 
Owing to the higher latitude, the climate as a whole is rather cool, 
but severe frost is rare in the lowlands, and the effect of the sur- 
rounding ocean is seen in the relatively small range of temperature 
due to latitude. Thus between Auckland in the North Island, 
and Invercargill, ten degrees further south, there is less than 10°F. 
difference in the mean annual temperatures. 

For the most part, rain is abundant and well distributed, and 
originally extensive forests covered much of the country. Most 
of the forest has disappeared, especially in the North Island. 
There are, however, in the South Island, areas of light rainfall, 
which are natural grass-lands, and may be compared to the Amer- 
ican prairies. The most important of these is the Canterbury 
Plain. 

New Zealand is very mountainous, and there are extensive 
volcanic formations especially in the North Island. The Rotorua 
district, familiar to tourists, recalls the Yellowstone Park, with 
its geysers and thermal springs. 

The lofty snow-clad Southern Alps parallelling the west coast of 
the South Island, culminate in Mt. Cook, over 12,000 feet high, 
from which extensive glaciers descend, almost to its base. These 
mountains greatly influence the climate of the South Island, 
intercepting a large part of the moisture from the ocean, so that 
in the narrow strip of territory, Westland, between the mountains 
and the coast, there are stations with as much as 200 inches of 
annual rainfall; while Christchurch, on the east coast has only 
about 25 inches, and some eastern stations even less. 

This eastern dry region is mostly treeless, the ground covered 
with coarse tussock-grasses, especially Festuca N ovae-Zeylandeae, 




Plate XL VI.— Giant Kauri (Ayuthis Australia), New Zealand. 



337 



338 



OUTLINE OF PLANT GEOGRAPHY 



and Poa caespitosa. The contrast between this region and the 
dense evergreen rain-forest of Westland, is very marked. 

The most important tree of the great forest which once covered 
most of the North Island, is the Kauri (Agathis Australis). Very 
little remains of this primitive forest, and the Kauri is almost 
extinct except in a few reservations. This magnificent tree is very 
different in appearance from any northern conifer. While the 
young tree has the same symmetrical pyramidal form, this is 




Fig. 92. — Cabbage-trees (Cordyline Australis) and native flax {Phormium tenax), 
North Island, New Zealand. Photo., Mr. W. D. Reid. 



later lost, and the mature tree has an almost perfectly cylindrical 
bole, 60-80 ft. high, sometimes 8-10 feet in diameter, or even 
more, which divides abruptly into several widely divergent 
branches, supporting an immense spreading crown, which over- 
tops all the other trees. 

The interior of the Kauri forest with its huge smooth gray pillars 
is most impressive. Associated with the Kauri are other char- 
acteristic trees. Among these are several members of the yew 
family, e. g., "Totara" {Podocarpus Totara); "Rimu" (Dacrydium 



THE SOUTH TEMPERATE ZONE 



339 



cupressinum) , both valuable timber-trees, and the curious Phylr 

locladus trichomanaides whose flattened leaf-like .-hoots, or "clado- 
des" look like fern leaves. Other common trees are H'< inmannia 
sylvicola (Saxifragaceae), and BeiUchmiedia taraire, of the laurel 
family. Weinmannia is said to be the commonest tree of New 
Zealand. 

Many very ornamental evergreen shrubs are common, e. g., 
Coprosma, Pittosporum, Nothopanax, and as everywhere in 




Fig. 93. — Todea (Leptopteris) superba. Tree-ferns in background. 



New Zealand, ferns are much in evidence. The tree-ferns of New 

Zealand are especially beautiful and abundant. Cyathea medtd- 
lan's, sometimes upwards of 50 feet high, is probably unsurpassed 
in beauty by any tree-fern. 

In the wet forests lianas and epiphytes are abundant, the latter 

including many bryophytes and ferns, as well as a g 1 many 

flowering plants, among which several orchids may be noted; 
but these are much inferior in beauty to those of northern Aus- 
tralia. A very common epiphyte, belonging to the lily family is 
Astelia Solandcri whose great bunches of sword-shaped 1< 




Plate XLVII— Tree-ferns (Cyathea medullaris), North Island, New Zealand. 



340 



THE SOUTH TEMPERATE ZONE 341 

cling to the trunks and branches of the trees. It is often found 
attached to the slender trunk of the "Nikau" {Rhopalostylis 
sapida), very common in the North Island, and the only palm 
native to New Zealand. 

Where the cleared land has been abandoned, it is often invaded 
b}' the ubiquitous bracken (Pteridium aquilinum), and another 
plant which quickly takes possession is the " Manuka" (Lepto- 
spermum scoparium), a shrub closely resembling some of the Aus- 
tralian species. When in bloom, the profusion of pretty white 
flowers is quite ornamental. 

In open moist places, all over New Zealand, two characteristic 
plants at once attract attention. The native flax (Phormium 
tenax) and the " cabbage-tree" (Cordyline Anstralis), both hand- 
some plants, are often seen in cultivation. The latter, sometimes 
in California known as " Yucca-palm," is not very distantly 
related to our native Yuccas. The flax yields an abundant strong 
fibre which is manufactured on a large scale and is one of the most 
important products of the country. In November, when these 
two plants are in bloom, they present a fine picture. The flax 
sends up from its great tufts of broad leaves, four or five feet high, 
flower stalks of twice that height, bearing racemes of dark red 
flowers, which are frequented by the honey-sucking birds. The 
stately cabbage-trees have big clusters of small white, very fra- 
grant flowers. 

Among the common trees of New Zealand are several species of 
Metrosideros (Myrtaceae), a genus distributed over Polynesia and 
Australasia. M. robusta, the "Rata," is a handsome tree with 
glossy foliage, and a profusion of bright red flowers, the si aniens, 
as in many other Myrtaceae, being the showy part, of the flower. 
M. tomentosa is very common about Auckland, and M. lucida in 
the South Island. Some of the species are climbers, and M. robusta 
begins life as an epiphyte behaving like many of the tropical ban- 
yan figs. 

Further south the forest is of much the same type, but the 
Kauri is entirely absent, and finally the Nikau-palm disappears. 
In the extreme southern part of the North Island, near Wellington, 
one first encounters the evergreen beeches, which are very char- 
acteristic of many districts in the South Island. 

The predominant forest near Wellington is a mixed one. Fine 




Plate XLVIII.— Nikau-palm (Rhopalostylis sapida), North Island, New Zealand. 



342 



THE SOUTH TEMPERATE ZONE 343 

specimens of Knightia cxcelsa, one of the two specie- of Proteao 
found in New Zealand, were seen about Wellington. This is a hand- 
some tree somewhat resembling the Ausl ralian Banksias. Another 
interesting small tree, is a species of Fuchsia (F. excorticata). New 
Zealand has three species of this otherwise American genu-. 

The beech forest near Wellington is composed exclusively of two 
species, Nothofagus fasca and N. Menziesii. The forest is more 
open than the mixed forests of the North Island. Except for 
their very small leaves, they are not unlike the beeches of the noil h- 
ern forests, and also remind one of the alders of the northern Pacific 
coast. 

Cook's Strait separating the North and South Islands seems to 
afford no appreciable barrier to plant migration, there being little 
difference in the vegetation on the two sides of the strait, indicating 
that the separation of the islands is too recent for any marked 
changes in the vegetation. 

The eastern part of the South Island is largely occupied by open 
grass-land, the Canterbury Plain, in which is situated the impor- 
tant city of Christchurch, being the most extensive. This is a 
rich agricultural and pastoral region. Where it has not been cul- 
tivated it is covered by coarse tussock-grasses, and this is also true 
of the eastern foot-hills of the mountains. In a few localitii 
where the ground is low and moist, and in some sheltered ravines 
in the coastal hills, there are patches of forest. 

Crossing the South Island from Christchurch to the west coast . 
one traverses a great variety of country, with a correspondingly 
varied vegetation. 

The tussock grass-land of the Centerbury Plain extends over 
the lower slopes of the mountains but gives place, very abruptly, 
to dense woods of the mountain beech (Nothofagus Cliffortioidi 
marking the beginning of the western rainy district. 

Al Arthur's Pass, about 3,000 feet elevation, the increasing 
moisture is still more evident. The country is an open rocky 
moorland, with a great variety of herbaceous plants and low shrubs. 
Preeminent among the flowers is the superb giant buttercup 
(Ranunculus Lyallii), with great clusters of big snow-white blos- 
soms, and immense almost circular entire leaves. Another com- 
mon and beautiful flower is Ourisia jnacroairpn, BOmewhat like 
a white Mimulus. 



344 



OUTLINE OF PLANT GEOGRAPHY 




Fia. 94. — Beech forest (X oth of agas fused), South Island, New Zealand. The fern 
is Polystichum vestitum. Photo., Mr. W. D. Reid. 

There is a very characteristic sub-alpine scrub, including several 
species of Veronica, a genus remarkably developed in New Zea- 



THE SOUTH TEMPERATE ZONK 



345 



land, as well as many others. Among the latter are various woody 
Compositae (Olearia, Celmisia, Senecio); a leafless leguminous 
shrub (Carmichaelia) ; Gaultheria, Pseudopanax, and most gf lik- 
ing of all the conspicuous Dracaena-like Draco phyllum Travcrsii 
low tree with bunches of long reddish leaves at the tips of the 
straggling branches. In spite of the Yucca-like aspect, it is a 
heath, of the family Epacridaceae, especially developed in Aus- 




; 



Wmm ***** 




*« **•» 




M'- 






mF* 




Fig. 95.— Tussock grass-land (Poa caespitosa), South Island. New Zealand. Photo., 

Mr. W. D. Reid. 



tralia. A second species of flax (Phormium Coloisoi) is common 
in this district. 

The descent toward the west coast through the magnificent 
Otira Gorge, is one of the finest pieces of scenery in New Zealand. 
Luxuriant forest completely covers the precipitous walls of the 
canyon, and testifies to the heavy rainfall of the western slopes of 

the mountains. 

The beech forest of the higher elevations gradually gives way 

to the typical West-land rain-forest, and there is an increasing 



346 OUTLINE OF PLANT GEOGRAPHY 

luxuriance in the roadside vegetation, where there is a profusion 
of moisture-loving plants like liverworts and ferns, and such her- 
baceous flowers as violets and the interesting genus Gunnera, 
which is especially developed in New Zealand. Tree-ferns become 
more and more abundant as one descends, and in the typical 
West land forest are developed in magnificent profusion. 

The Westland rain-forest is one of extraordinary luxuriance. 
The very heavy precipitation and mild temperature result in a rich 
vegetation that recalls the Malayan jungle. Composed entirely 
of evergreen trees and shrubs, draped with giant creepers and 
epiphytes, and with groves of tall tree-ferns, it is hard to realize 
that this forest, in S. lat. 43°, corresponds in latitude to Buffalo 
or Milwaukee. 

This forest is dominated by two trees of the yew family, Po- 
et oca r pus dacrydioides and Dacrydium cupressinum, and has been 
called a "Taxad" forest for this reason. However, other trees 
are also common, especially Weinmannia, already referred to in 
connection with the forest of the North Island. Related to this 
is another abundant species, Quinquinia acutifolia. A very com- 
mon shrub is Aristotelia racemosa, with rather pretty pinkish 
flowers; other abundant shrubs and small trees are species of 
Coprosma, Metrosideros and Pseudopanax. 

Ferns, mosses and liverworts luxuriate in these wet forests, and 
club-mosses are abundant, both terrestrial and epiphytic species. 
The interesting Tmesipteris, formerly associated with the ly- 
copods, but now assigned to a class of its own (Psilotineae) is 
common as an epiphyte in many places. 

Of the tree-ferns the commonest is Dicksonia squarrosa, some- 
times 20-30 feet high. Less abundant is Hemitelia Smithii. Of 
the epiphytic ferns, the beautiful filmy-ferns are especially abun- 
dant and luxuriant. Of these the very characteristic kidney-fern 
{Trichomanes reniforme), with vivid green, rather leathery leaves 
is peculiar to New Zealand, as are several other species of Hy- 
menophyllum and Trichomanes. Another abundant and beauti- 
ful fern, confined to New Zealand is Todea (Leptopteris) superba, 
belonging to the same family, Osmunclaceae, as the royal fern and 
cinnamon fern of the United States. 

As might be expected, these saturated forests are a veritable 
garden of mosses and liverworts which drape the trunks and 



the south ti:mim;hate zone 



347 



branches of the trees, and form thick carpets on the forest floor, 
and great cushions over every stump and fallen log. Big tussocks 
of Sphagnum grow in the forest pools, and here and there are 
colonies of the giant Dawsonia superba, the last word in moss- 
evolution. 

The abundance and luxuriance of the liverworts is astounding; 
it is doubtful if anywhere else in the world is a richer growth of 




Fig. 96.— Giant moss (Dawsonia superba), Kauri forest, North Island, New Zea- 
land. Photo., Dr. L. Cockayne. 

these interesting forms. They include some of the giants of the 
class, one in particular, Monodea Forsteri, being the largest liver- 
wort that the writer has ever seen. 

The New Zealand rain-forests are rich in climbing plants and 
epiphytes. Of the latter some are permanent epiphytes, others 
begin life as epiphytes but later send roots downward and assume 
a terrestrial habit. The permanent epiphytes include many m< — », 
liverworts, lycopods and ferns, as well as a good many flowering 
plants like orchids, Peperomia, Astelia and others. Several New 
Zealand trees begin life as epiphytes. The seeds germinate on 



348 



OUTLINE OF PLANT GEOGRAPHY 



the branches of trees, and presently the young plant sends down 
roots which descend along the trunk of the host until they reach 




Fig. 97.— Sub-alpine scrub, Arthur's Pass, South Island, New Zealand. Dra- 
cophyllum Traversii; in front, Suttonia divaricata. Photo., Dr. L. Cockayne. 

the ground. Sometimes these roots coalesce into a more or less 
solid trunk, and the host may be completely strangled. The 
"rata" is the most conspicuous of these temporary epiphytes. 
Other species are Dracophyllum arboreum and Griselinea littoralis. 



THE SOUTH TEMPERATE ZONE 349 

Compared with Australia, New Zealand has few showy flowers, a 
remarkable number of the plants having white or greenish flowers. 
There is, however, a considerable number of marked exceptions 

to this, like the scarlet flowers of the rata and native flax; the bright 
yellow of Sophora tetraptera, and the showy blue or purple of many 
species of Veronica and various Compositae, like Celmisia. 

When the floras of New Zealand and Australia arc compared, 
there are fewer correspondences than might be anticipated, and 
these are largely of northern genera which are also common to the 
Malayan flora. The Malayan element, however, is relatively 
of much greater importance in New Zealand, where in spite of the 
much cooler climate, a large proportion of the trees and shrub- 
are more or less evidently related to Malayan types. There is 
very strong evidence of former land extensions to the north of 
New Zealand, and it is quite likely that the Malayan genera which 
New Zealand shares with Australia, have reached the former 
country quite independently. 

The distinctly Australian genera are relatively few in New 
Zealand, some of the most important like Eucalyptus, Acacia and 
Grevillea, being totally absent. The myrtle family, with over 
800 species in Australia has a scant 20 in New Zealand, and the 
Proteaceae, with approximately 650 in Australia, have but two 
species in New Zealand. The characteristic Australian family 
Epacridaceae is well represented in New Zealand, as well as sev- 
eral Australian genera of Orchidaceae, Leguminosae and Composi- 
tae; but it has been suggested that some of these may have origi- 
nated in New Zealand, and later migrated to Australia. 

The Sub-antarctic Flora 

Reference has already been made to the presence in southeast 
Australia and Tasmania of certain plants which are evidently 
related to species found in sub-antarctic South America. This 
"Fuegian" flora is much more evident in New Zealand, and has 
been the subject of many careful investigations. In one of the 
more recent of these publications 1 it is stated that 47 families 

1 Seottsburg, K., "Notes on the Relation between the Floras of Sub-antarctio 
South America and New Zealand," Plant World, May. 1915. 

Cockayne, L., New Zealand Plants and Their Story, Wellington, 1919. 



350 



OUTLINE OF PLANT GEOGRAPHY 



and 68 genera are common to the two regions, and there are even 
several identical species. The southern beeches (Nothofagus) 
have already been mentioned, but there are other more or less 
familiar genera, like Fuchsia, Geranium, Myosotis, Veronica, Ra- 
nunculus, etc., as well as others, e. g., Ourisia, Drimys, Pernettya, 
Libertia, Laurelia, Astelia, Miihlenbeckia, etc. 

So difficult is it to explain the transport of so many forms across 
the immense stretch of ocean between New Zealand and South 




Fig. 98. — Westland rain-forest, South Island, New Zealand. Photo., 

Dr. L. Cockayne 

America, that one is compelled to assume some former land con- 
nections, probably via some northern extension of the present 
antarctic regions. Such fossil evidence as is available shows that 
some of these common types formerly existed in the Antarctic. 
Further investigation may show that there was a northward 
extension of the antarctic regions, with climatic conditions suit- 
able for vegetation. If further discoveries of fossils should indicate, 
as in the northern hemisphere, that a uniform vegetation existed 
in Tertiary time throughout what is now the antarctic regions, 
it would explain much of the present plant distribution in the 



THE SOUTH TEMPERATE ZONE 361 

southern hemisphere. Migrants from such a common temperate 
flora, shut off in the at present widely sundered regions, would 
in course of time show greater or less divergence, depending upon 
the difference in environment. The cool humid climates of Fuegia, 

Tasmania and southern New Zealand would be more likely to 
preserve these ancient forms with little change, than the hoi 
arid climate of most of Australia and South Africa. 

There is sufficient similarity in the floras of South Africa and 
Australia to warrant the assumption of some former land connec- 
tions ; but such, if they did exist, were severed at a very remote 
period. The high degree of endemism in the two regions, points 
to a long period of isolation; and while, for example, such a pecu- 
liarly southern family as the Proteaceae, is abundantly represented 
in both regions, there is not a single genus common to the two. 

The rain-forests of Queensland and New South Wales are prob- 
ably the remnants of a once much more extensive flora of Malayan 
type. It is certain that at no very remote period, geologically 
speaking, northeastern Australia and Papua were united, and this 
is amply shown by both the floras and faunas of the two regions. 

Western Australia, however, is supposed to be part of a very 
ancient continent which was at one time completely separated 
from what is now eastern Australia. In this ancient western con- 
tinent it has been thought that most of the peculiar autochtho- 
nous Australian types originated. The typical Australian flora 
shows a very high degree of endemism, this reaching its maximum 
in Western Australia. The proportion of both endemic genera 
and species is very high, but the number of families represented 
is relatively small. The large number of species in certain genera 
is notable. Thus the genus Eucalyptus has over 200 species, 
and of the Leguminosae, the largest family in the Australian 
flora, over 400 species, or approximately one third of the total 
number, belong to the single genus Acacia. The Myrtaceae, the 
second largest Australian family, has over 800 species and the 
Proteaceae more than 650. 1 Several families, e. g., Candol- 
leaceae, Goodeniaceae, are almost exclusively Australian, and 
especially developed in West Australia. 

The typical Australian types are largely adapted to dry condi- 
tions, and after the union of eastern and western Australia, it may 

1 Maiden, loc. cit., p. LI 



352 



OUTLINE OF PLANT GEOGRAPHY 




Fig. 99. — Vegetation of coastal cliff, southern part of South Island, New Zea- 
land. At center, Celmisia Lindsayi; foreground, Poa Astoni. Photo., Dr. 
L. Cockayne. 



THE SOUTH TEMPERATE ZONE 



363 



be assumed that the extreme aridity and poor soils of the centra] 
part of the continent would be much better adapted to the xero- 
phytes from the west than to the Malayan rain-foresi types, which 
seem to have been to a great extent evicted by the drought- 
resistant western immigrants, and are now restricted i<> compar- 
atively limited areas of good soil and adequate moisture. 




Fig. 100. — Alpine grass-land, elevation 4.500 feet. Gcntiana corymbifera in flower. 
South Island, New Zealand. Photo., Mr. W. D. Re id. 

The autochthonous types have for the most part remained in 
Australia. Eucalyptus, Acacia, and a few Proteaceae, and a few 
others are found in the savannas of southern Papua, and some 
even reach the drier parts of the Philippines, and range through 
Polynesia; but the great majority of the true Australian types 
are unknown beyond the Australian continent. 

Agriculture and Horticulture in Australasia 

The cooler parts of Australia and all of New Zealand are adapted 
to the usual crops of the temperate zones. In Australia wheat i< 



354 OUTLINE OF PLANT GEOGRAPHY 

grown on a large .scale and is much the most important agricultural 
product. Corn, oats, and barley are grown in considerable quan- 
tities, and alfalfa is an important forage crop in many places. 
Fruits and vegetables of many kinds thrive, and some fruit is ex- 
ported, especially apples from Tasmania. Grapes, figs, passion- 
fruit and oranges thrive in southern Australia, and wine of excel- 
lent quality is an important product, especially in South Australia. 
Dried fruits are made under much the same conditions as in 
California, but as yet the industry is still on a relatively small 

scale. 

In Queensland sugar is grown in considerable quantities, and 
tropical fruits, pineapples, bananas and papayas, are produced on 
a commercial scale. 

The climate of New Zealand is too cool for tropical fruits, and 
the cultivated fruits and vegetables are all the familiar ones of 
the temperate zone. 

Weeds 

As in all other lands settled by Europeans, there have also 
come many plant immigrants, not always welcome. These weeds 
hail from many countries. In the hotter and dryer parts of Aus- 
tralia, many of the weeds have come from India, Brazil or Africa, 
while in the temperate parts of Australia and New Zealand, they 
are the familiar European and American weeds, like sorrel, dock, 
thistles, plantain, etc. 

Parts of Australia, especially Queensland, have been invaded 
by the American prickly-pears (Opuntia spp.) which have proved 
a very serious pest. It is said that in Queensland, 30,000,000 
acres have been overrun by one species, causing immense damage. 
America has also contributed the cockle-bur (Xanthium), Stramo- 
nium and some other troublesome weeds. In the cooler and moister 
parts of Australia and New Zealand, European blackberries, 
sweet-brier, gorse and broom, have escaped from cultivation and 
become very difficult to eradicate. 

South Africa, whose climate is so like that of Australia, has 
contributed a number of plants which have become more or less 
completely naturalized. The common calla lily may often be 
seen growing in ditches in southern Australia, and several hand- 
some South African Iridaceae, Ixia, Sparaxis, Watsonia and 



THE SOUTH TEMPERATE ZOM. 355 

Homeria, are sometimes seen growing along the railway embank- 
ments and elsewhere. Homeria is said to be poisonous, and may 
be ranked as a weed. A showy yellow Oxalis (0. cernua) has also 
run wild, and the "Cape-weed" {Cryptostemma calendulacea) 
covers acres with its light yellow daisy flowers. 1 

Temperate South America 

The transition from the tropical regions of Brazil to temper 
Argentina and Uruguay is very gradual. Southern Brazil extends 
beyond the Tropic of Capricorn, and the highlands have a climate 
not unlike that of parts of South Africa. Like the South African 
plateau, the rain, which is much heavier than in central Africa. 
falls mostly in summer, and very hot summers contrast with 
relatively cold winters. 

Much of the country is open grass-land, but the valleys show a 
luxuriant sub-tropical vegetation, and there are many beautiful 
flowering trees, shrubs and creepers, some of which are not rare in 
cultivation. Among these may be mentioned, the beautiful Jac- 
aranda, with its masses of blue flowers, and graceful foliage; the 
gorgeous orange Bignonia venusta, and the purple Bougainvillea. 

Southern Brazil is also the home of an Araucaria (A. Brazilimm), 
a very peculiar genus of conifers, confined to South America 
and the Australian region. This tree forms pure stands, like the 
northern pines, and associated with it is an undergrowth of "mal 
{Ilex Paraguayensis), a shrub of the holly family, whose lea\ 
yield the mate tea, extensively used by the natives, and now- 
beginning to be an article of export. 

Among the sub-tropical types of southern Brazil and northern 
Argentina, are various palms, some of which are in cultivation, 
like Cocos plumosa and C. datil, often seen in southern California. 

Paraguay, like southern Brazil, has a sub-tropical climate with 
abundant precipitation especially in the eastern portion, so that 
there are luxuriant forests mainly of evergreen trees, but with 
predominantly deciduous species on the drier soils. Westward 
the forest becomes more restricted in its range and is interspersed 
with open prairies, with some palms and scattered thickets.'- The 

1 For a fuller :u-oount of tin- Australasian vegetation, Bee the writer's pa] 
in the American Journal of Botany, Vol. X, January, April. December, 192 

2 Hardy, M. E., Geography of Plants, < Oxford, 1920, p. 1 5 












356 



THE SOUTH TEMPERATE ZONE 3o7 

Paraguay tea, or mate*, is abundant in tin's region and collected 

in great quantities. 

The Paraguay river is subject to greal floods, and the low count ry 
is then inundated so that the land adjacent to the river becomes 
an immense swamp. 

South of Brazil and Paraguay, and east of the Andes lies the 
great plain of Argentina, the pampas, covering thousands of 
miles with a sea of grass, like the North American prairies. As in 
North America, the western portions of these plains are arid and 
broken, and sparsely covered with bunch-grasses, interspersed 
with tufts of dry thorny shrubs and Cacti, much like the deserts of 
Arizona and southern California. Salt pans, where the barren 
ground is covered with a film of white alkali are also reminiscent of 
our own southwest. 

The pampa proper extends from Uruguay to the Rio Colorado 
near the northern boundary of Patagonia. The general aspect of 
the pampas must be much like the plains of the central United 
States. The grasses are mostly bunch-grasses belonging to several 
genera — Stipa, Aristida, Andropogon, Paspalum, Panicum and 
others, and these completely dominate the landscape. Where 
water settles in the hollows of the rolling prairie, there may be a 
continuous turf of finer grasses, and flowering herbs. Originally 
great numbers of ostriches, guanacos, and many small rodents 
inhabited these grass-lands; but with the coming of the white man. 
these have become greatly reduced in numbers, and now t he pampas 
furnish pasturage for vast herds of cattle and horses. With the 
rapid settlement of the Argentine, vast areas have gone under the 
plow, and the Argentine wheat and corn compete in world markets 
with the grain of North America, Australia, India and Russia. 

As in all newly settled countries, plant immigrants have come, 
and European weeds have invaded the cull ivated areas. Especially 
notable is the cardoon-thistle (Cynara Carduncutus) which is said 
to cover extensive tracts of country almost to the exclusion of 
other vegetation. 

South America narrows rapidly southward and nowhere is tin 4 
climate of the pronounced continental type found in most parts of 
the northern hemisphere in corresponding latitude-, although 
there is a marked difference between winter and summer. 

Buenos Aires, in about the same latitude as Los Angeles, has 



358 OUTLINE OF PLANT GEOGRAPHY 

much the same range of temperature, viz., 104°-32°F., but the rain- 
fall is twice as great. The southern extremity of Patagonia, has 
a harsh, but not extreme climate, comparable with that of the 
extreme north of the British Islands. 

The greater part of Patagonia is a most forbidding semi-desert, 
a sandy or stony broken plain, with scanty vegetation comprising 
only the hardiest of plants. The scrubby bushes have small 
leathery leaves, and are often hairy or sticky. Showy flowers are 
almost wanting, weedy Compositae, plantain and verbenas being 
among the characteristic plants. 1 

The southernmost part of Patagonia has much more rain, and 
the climate is a moist, cloudy and windy one, with much less range 
of temperature than the drier region to the northeast. The 
stormy climate is not conducive to tree growth, but conditions 
favor the development of a moorland vegetation. Tussock- 
grasses (Poa fiabellata) form huge tufts over the dreary moorland, 
and prostrate evergreen shrubs cover the ground in places. 2 

The flora of the Falkland Islands whose climate is even less 
genial than that of the mainland, has been somewhat carefully 
studied. 3 130 species of flowering plants have been described, of 
which 26 are endemic. The ferns and mosses number 75, and the 
algae and fungi, 173. The most conspicuous plants are the 
tussock-grasses, and of the prostrate shrubs, two are notable, a 
peculiar umbellifer (Azorella glebaria) and a myrtle (Myrtus 
nummidaria). 

Fuegia 

The great Andean chain gradually diminishes in height as it 
approaches the extreme southern part of the continent. The lower 
slopes, and the adjacent coast receive much more rain than the 
east coast of Patagonia, and the climate is much milder, so that 
conditions are favorable for a relatively rich vegetation. The same 
conditions prevail in Tierra del Fuego, across the Straits of Magel- 
lan, and the Fuegian region develops a low scrub forest composed 
mainly of the southern beeches (Nothofagus antarctica and N. bet- 
uloides), with a dense undergrowth of shrubs and herbaceous 
flowering plants, and a rich growth of ferns, mosses and lichens. 
The Fuegian flora has a considerable number of species either 

1 Drude, loc. eit., 535. 2 Hardy, loc. cit., 162. 3 Drudc, loc. cit., 540. 



THE SOUTH TEMPERATE ZONE 3" 

identical with or related to forms found in New Zealand, Tasmania 
and parts of Australia. Anion*!; these are the species of < runnera, 
Astelia, Nertera, and Nothofagus. A single conifer, Libocedrus 
tetragona, is found in the Fuegian region, other species occur 

further north in the Chilean Andes, and another is L. decum 
the incense cedar of California. 

Hardy compares the climate and vegetation of Fuegia with 
that of the north of Great Britain. 

Chile 

Chile occupies the Pacific coastal strip of South America, be1 ween 
latitude 18° and 55°, corresponding in North America to the coasi 
from Central Mexico to southern Alaska, and there is a striking 
similarity in the climates of the two regions in corresponding 
latitudes, due to similar conditions. As in North America, the 
narrow coastal belt is bounded on the east by the great Cordillera, 
and the climate is a pronounced maritime one being dominated 
by the winds from the Pacific. 

Of course, as Chile lies in the southern hemisphere, the ons 
are reversed when compared with North America, and the northern 
regions are the hot ones. Like the west coast of the United State-. 
winter is the rainy season, and is associated with northerly winds 
corresponding to the rain-bringing south winds in California; 
while the summer fair-weather southwest winds correspond to 
the prevailing northwest summer winds along the Californian 
coast. 

All of northern Chile is extremely dry — practically rainless, in 
fact, and almost destitute of vegetation. This is the region of the 
famous nitrate deposits, the source of great wealth to the country. 
This long stretch of arid country extending into the tropics, forms 
an effectual barrier to the southward migration of tropical plants, 
which are almost entirely wanting in the temperate parts of ( Jhile. 

The scanty rainfall of all of northern and much of the coastal 
region of central Chile prevents the growth of any plants except 
those adapted to long periods of drought. It is not remarkable, 
therefore, that as in corresponding regions of North America, 
Cacti play a very important role in the flora. Other dry region 
plants like species of Euphorbia, Croton, Cassia, Ephedra, as well 



O -S fa Jb 

3 

J -^ T3 g -2 




360 



THE SOUTH TEMPERATE ZONE 361 

as a good many bulbous plants and short-lived annual-, arc also 
characteristic of the region. 
The country about Valparaiso, which in latitude and climate may 

be compared to southern California, has a flora which is decidedly 
reminiscent of the latter region. 1 

There are many genera familiar to the Californian botanist, 
e. g., Calandrinia, Baccharis, Gilia, Lupinus, Sisyrinchium, etc, 
but there are also many which are exclusively South American. 
Some of these are very showy, and are cultivated in our garden- 
and greenhouses. Calceolaria, Schizanthus, nasturtiums and 
Petunias, are familiar instances of these herbaceous plants, while 
in the moister localities like ravines and the higher mountains, 
are many trees and shrubs which are highly prized in cultivation. 

Some of the common weeds have come from the Mediterranean 
regions, and are also common in California. Among the earliest 
plants to respond to the first autumn rains are two common weeds, 
the bur-clover (Medicago denticulata) and the " Alfilaria" (Erodium 
cicutarium) both very common in California, where the seeds 
sprout within two or three days after the first good rain and soon 
cover the bare ground with a film of fresh green. 

Among the characteristic species of Valparaiso, a few may be 
mentioned. 2 Near the shore on granite banks are species of Bahia, 
Eupatorium, Leuceria, Senecio, Eryngium, Puja (Bromeliaceae), 
Lobelia. Of the herbaceous plants Calceolaria, various Crucif- 
erae, Sisyrinchium, Cerastium, and various grasses. 

On the mountain slopes and on the plateau back of Valparaiso 
Reiche mentions, among others, the following as character- 
istic. Low bushes and scrub included species of Baccharis, Muh- 
lenbeckia, Azara, Flourensia, Haplopappus, and several others; 
associated with these were many showy herbaceous plants, e. 
Sisyrinchium, Scilla, Stenandrium, Thecophilaea, while occasion- 
ally a Puja or Cereus was seen. A few climbing plants were also 
noted, especially a yam (Dioscorea), and Aristolochia ChtlensU. 

Near Valparaiso are numerous mountain gorges in which there 
is a dense growth of tall shrubs, including some showy forms like 
Fuchsia, Eupatorium and Lobelia, as well as others less familiar. 
Among the interesting herbaceous plant- is a wild potato, Soianum 

1 Reiche, K., PftanzenoerbreUung in Chile, Die Vegetation deb VIII, 196 

2 Reiche, loc. cit. 







362 



THE SOUTH TEMPERATE ZONE 

Maglia. In this region also, is a fine palm [Jubaea spedabil 
One of the largest groves of this palm occurs al Cocolan, m lat. 

34° 10'. In California, in almost the same latitude north, is the 
only native palm, Washingtonia filifera. 
South of 35° the rainfall increases and in favorable localities, 

true forests begin, increasing southward in extent and luxuriance 
with the rapidly augmented precipitation. 

Along the coast, opening to the sea, are protected valleys, re- 
calling the redwood canyons of central California, and harboring 
a fairly heavy forest in which the beeches, some evergreen, oth( 
deciduous, are the most important trees. These beeches are as 
has been pointed out, a prominent feature of the sub-antarctic 
forests of Fuegia, New Zealand, Tasmania, and associated with 
them are also other tree genera common to the southermost pa 
of South America and Australasia, e. g., Weinmannia, Podocarpu-. 
Drimys, as well as a good many shrubs and herbaceous speci< 
One in particular, Nertera depressa, sl pretty little evergreen t rail- 
ing plant, has an extraordinary range, being common in New 
Zealand and Tasmania, and also known from some of the moun- 
tains of western Malaya. 

Southward from Valparaiso there is a rapid increase in the rain- 
fall, and ferns, mosses and other moisture-loving plants become 
more and more abundant, and coniferous trees play a much more 
important role in the forest. The myrtle family is represented 
by species of Myrtus and Eugenia, both genera also abundantly 
represented in the Australasian and Malayan rain-forests. The 
myrtle family is largely developed in the tropical forests of South 
America, as it is in Australia, and another characteristic Australian 
family, the Proteaceae, has also a number of genera, two of which, 
Embothrium and Lomatia are shared with Australia. Another 
genus, Roupala is exclusively American. 

The Chilean Coniferae are mostly southern genera, Podocarpus, 
Libocedrus, Saxegothaea and Araucaria, the latter, as already 
mentioned, being another genus which South America shares with 
Australia. The Chilean species, A. imbricata, popularly known 
"monkey-puzzle," grows in the mountains of Chile at an altitude 
of 2,000-3,000 feet. 

Central Chile, both in climate and topography, much resembles 
the corresponding regions of California, and the central valley 



364 OUTLINE OF PLANT GEOGRAPHY 

between the Andes and the coastal hills has been compared with 
the great central valley of California. There is the same expanse 




Fig. 101.— Beech-forest, Western Argentina, elevation 4,000 feet. 

Photo., Dr. Bailey WiUis. 

of open grass-land, with an extensive development of evergreen, 
often thorny shrubs in the foot-hills, like the chaparral of the foot- 
hills of the Sacramento and San Joaquin Valleys. 



THE SOUTH TEMPERATE ZONE 56 

On the coast the rainfall becomes very heavy. Valdivia, lat. 
40°, has 100 inches annually, almost the same as on the coast of 
California in the same latitude north, and the heavy rain-forei 
of central Chile have their counterpart in the magnificent conif- 
erous forests of northern California, Oregon and Washington. 
In both regions the climate is a cool and uniform one, which with 
the abundant moisture results in evergreen forests of the great- 
luxuriance. 

The constituents of these forests in Chile and North America, 
however, are very different. While the northern forests are com- 
posed almost exclusively of conifers — redwood, spruce, fir, hemlock 
and cedar, etc., these play a very subordinate role in the Chilean 
coastal forest, where the prevailing trees are beeches and other 
broad-leaved evergreens, quite wanting in the northern forests. 
Among the most characteristic of these are the following -Drimys 
Winteri (Magnoliaceae), Laurelia aromatica (Monimiaceae), Myr- 
tus luma, Aextoxicum punctatum (Euphorbiaceae), Flotowia 
diacanthoides (Compositae), Weinmannia trichosperma (Cunonia- 
ceae), Cryptocarya peumus (Lauraceae). Species of Laurelia and 
Weinmannia are both important trees of New Zealand. Only 
a single conifer, Podocarpus Chilensis, is found in this forest, and 
this is not a dominant tree. Among the shrubs are species of 
Griselinea (Cornaceae), Lomatia and Embothrium (Proteaceae) ; 
Escallonia (Saxifragaceae) ; the latter with handsome glossy foliage 
and pretty white, pink or crimson flowers, often cultivated in 
California and other warm temperate regions. Fuchsias are also 
frequent, as well as evergreen barberries, myrtles, and the less 
familiar Baccharis, Aristotelia (Tiliaceae), and Pseudopanax. 
The two latter, with Fuchsia and Griselinia, are characteristic 
genera of New Zealand. 

These cool rain-forests abound in mosses, liverworts and ferns. 
among the latter a tree-fern (Alsopkila pruinata), and epiphytes 
abound, among which the filmy ferns are notable. 

Climbing plants are abundant including a scarlet nasturtium 
(Tropoeolum speciosum) and a beautiful climbing lily (Lapagma 
rosea), both occasionally seen in cultivation. Wild yams (Dios- 
corea), a vine, Cissus striata, and a number of less familiar genera 
occur/and several parasites of the mistletoe family arc common. 
Within the dark forest flowers arc scarce, but in clearings, and 



366 OUTLINE OF PLANT GEOGRAPHY 

at the edge of the forest are many shrubs and herbaceous plants 
of great beauty. Of the shrubs, the handsome Sophora tetraptera, 
with yellow pea-flowers is noteworthy, as the same species is wide- 
spread in New Zealand and also occurs in Lord Howe Island. 
Alstroemeria aurantiaca, sl showy lily sometimes seen in cultiva- 
tion, a raspberry (Rubus ulmifolius), sl violet, an orchid (Pogonia 
tetraphylla.). Calceolaria, Sisyrinchium, and Calandrinia are some 
of these flowers of the more open areas. Libertia, a liliaceous 
genus also found in Australasia, may also be cited. 

Ascending the mountains east of Valdivia, the rain-forest is 
replaced by one in which coniferous trees are more prominent. 
One of the most important commercially is the "Alerce" (Fit?- 
roya Patagonica) whose timber is highly esteemed and which has 
been pretty well exterminated in many places. Several other 
coniferous genera occur, viz., Saxegothaea, Podocarpus, Liboce- 
drus, the latter the only genus occurring in the United States. 
Of the lower shrubs, a species of Gaultheria recalls the "salal" 
of the Pacific coast, and the little wintergreen of Atlantic North 
America. 

Among the most remarkable of the Chilean plants is Gunnera 
Chilcnsis, sometimes seen in cultivation. It suggests a gigantic 
rhubarb with huge leaves 4-5 feet across. A still larger species, 
G. manicata is found in Brazil, and in Hawaii a very similar species, 
G. petaloidea lives in the mountain rain-forest. 

South of lat. 43°, there extends a chain of islands characterized 
by rain-forests in which mosses, liverworts and ferns are developed 
to an extraordinary degree, forming dense carpets on the forest 
floor, and covering the trunks and branches with a thick drapery. 
Tree-ferns, however, are apparently much less abundant than in 
the rain-forests in the same latitude in New Zealand. 

The rain-forest occupies the whole coast of southern Chile to 
the extreme tip of Fuegia; but with the decreasing temperature 
there is a marked falling off in the number of species, and the trees 
become more stunted; but the vegetation is still, for the most 
part, evergreen, for although the climate is raw and boisterous 
there is no excessive cold. 

The predominant trees are the same as in the forest further 
north, beeches, Libocedrus, Podocarpus, Weinmannia, Myrtus, 
Drimys, etc. There are extensive bogs with peat-mosses in which 



THE SOUTH TEMPERATE ZONE 367 

grow a good many plants closely related to the bogs of the far 
north, such as sundews, butter-wort (Pinguecula), marsh-marigold 

(Caltha), crowberry (Empetrum), and others. Of the lower ever- 
green growths are various ferns, including a Uleichenia. Dac- 
rydium and Orobolus are also characteristic genera. 

The Chilean flora, as might be expected from the great range of 
latitude, shows marked differences between the north and south. 
The extreme desert conditions of the north constitute an absolute 
barrier against invasion of plants from the moist tropics. This 
accounts for the complete absence in Chile of such striking families 
as the Araceae, Scitamineae, Bignoniaceae, Malpighiaceae, and 
the bamboos. The palms, so extensively developed in tropical 
America, are restricted to two species, one of which, Juania 
Australis, is confined to the island of Juan Fernandez. The 
Bromeliaceae, more xero phytic in habit, have a considerable 
number of representatives but are much less important than is 
the case in most other parts of South America. 

On the other hand, owing to the cool and moist coastal climate 
of central Chile, many sub-antarctic species extend far northward, 
a condition parallelled in California by the southward extension 
of many boreal species in the coastal redwood belt. In both regions 
there is also a migration southward along the higher parts of the 
great Cordillera. 

A comparison of the floras of California and Chile show upwards 
of 150 genera in common, and although a large part of these arc 
wide-spread in temperate climates, there are a good many strict ly 
American genera, and some confined to the Pacific slope. Such. 
for example, are many Cacti, the creosote-bush (Larrea), Bac- 
charis, Encelia, Grindelia, Orthocarpus, Mirabilis, and others. 

There has been probably a migration in both directions, as some 
genera are more characteristic of the north, others better developed 
in the southern hemisphere. Thus Calandrinia, which has sonic 
half dozen species in California, has many more in Chile, and also 
Australia, and is presumably of southern origin. On the other 
hand, Orthocarpus (Scrophulariaceae), with about 30 species in 
Pacific North America, is represented by a single species in the 

Andes. 

While the number of species common to Chile and the Pacific 
Coast of North America is small, there are several which could be 




368 



THE SOUTH TEMPERATE ZONE 3G9 

mentioned. Thus the Chilean strawberry (Fragaria club' 
is very common on the cliffs and sand dunes about San Francisco 

None of the Chilean conifers belong to northern types. Podo 
carpus is represented in the West Indies, but otherwise, except for 
Libocedrus with a solitary species in California, the Chilean co- 
nifers belong' to strictly austral genera, Araucaria and Fitzroya. 

Southern Chile has a flora which is unmistakably related to t hat 
of New Zealand and Southern Australia; indeed so intimate is this 
relationship, that it seems extremely likely that some sort of land 
connection must at one time have existed between these countries, 
now so widely severed. Not only are there many genera in com- 
mon, but some fifty species are cited as belonging to both regions. 

Many of the trees characteristic of the forests of sub-antarctic 
South America and New Zealand belong to the same genera. In 
both regions the antarctic beeches (Nothofagus) abound, and such 
genera as Weinmannia, Laurelia, Aristotelia and Drimys, char- 
acteristic of New Zealand, but quite unknown in America, except in 
the Chilean region, indicate that these have reached South America 
from some southern land which has disappeared, while the pres- 
ence in Chile of such a striking New Zealand species as Sophora 
tetraptera, already referred to, and the occurrence in New Zea- 
land of three species of the essentially South American genus 
Fuchsia, make it pretty certain that there must have been some 
much more intimate connection between South America and 
Australasia than now exists. So many are the corresponded 
between the Andean and sub-antarctic floras of South America 
and those of New Zealand, as to make it practically certain that 
these regions have been in connection at some former time. 
Presumably this connection was via some extension northward of 
the existing antarctic continent. 

Temperate South America has contributed many ornamental 
plants to our gardens. From South Brazil and Argentina come 
the Petunias, Verbenas, and Portulaca; from Chile the showy 
Calceolarias and Schizanthus of the greenhouses, Salpiglossifl and 
nasturtium-. 

The garden fuchsias are derived largely from Chilean species, 
while in milder climates the pepper tree (Schinus m<>ll<), the 
monkey-puzzle (Araucaria imbricata) evergreen barberries, espe- 
cially Berberis Dann'nii, Escallonias, the heath-like Fabiana, 



370 OUTLINE OF PLANT GEOGRAPHY 

passion-flowers, and the beautiful Lapageria rosea, are among a 
few of the notable horticultural contributions of Chile. 

More useful, if not ornamental, is the potato, several species of 
which are native to Chile and Peru. 

The Chilean Oceanic Islands 

Off the coast of Chile are two groups of volcanic islands said 
to be situated on a common submarine ridge. The southern 
group, Juan Fernandez, lies directly west of Valparaiso, the second, 
San Ambrosio and San Felix, further north, 900 km. from the 
coast. 

There are three islands in the Juan Fernandez group, two of 
them, Masatierra and Masafuera, having peaks respectively 1,000 
and 1,800 m. in elevation. There is an extensive evergreen forest 
developed over much of the two larger islands, but in the drier 
parts the vegetation is to a great extent herbaceous. In the driest 
districts, especially on rocky slopes and cliffs, are many xerophytes, 
among them a large bromeliad (Ochagavia elegans). 1 

The general character of the forest is much the same as that of 
the Chilean coast, but there is a very large proportion of endemic 
species. Perhaps the most notable is a palm (Juania Australis), 
with the exception of Jubaea spectabilis, the only Chilean palm. 

Ferns abound in the islands, many, like the filmy-ferns, being 
epiphytes, while tree ferns are also common. On Masafuera the 
elevated plateau of the interior is covered by an extensive growth 
of ferns, forming what has been called a " fern-steppe." 

According to Drude, 2 of the 102 species of flowering plants in 
Juan Fernandez, no less than 70 are endemic, and there are 10 
endemic genera. 

The archipelago of San Ambrosio and San Felix is very barren, 
and the flora extremely scanty. Professor Bailey Willis, of Stan- 
ford University, who recently visited San Felix, which formerly 
had extensive guano deposits, collected four species, one of which, 
Thamnoseris lacerata (Cichoraceae) is a monotypic species, endemic 
to the islands. 

1 Reicher, loc. cit., p. 267. 2 hoc. cit., p. 132, 



INDEX 



Abauria excelsa, 215 

Abies, see also Fir 

A. amabilis, 131 

A. concolor, 124, 127, Fig. 41 

A. grandis, 119, 131, 139 

A. lasiocarpa. 121-131, Fig. 30 

A. magnifica, 148 

A. pectinate, 40 

A. Pinsapo, 58, 62 

Abronia, 137 

Abyssinia, 170, 171 

Acacia, 52, 63, 169, 170, 171, 173, 181, 

189, 243, 257, 259, 316, 318, 332, 

349,351,353,357 
A. Arabica, 179 
A. giraffae, 173, 318, 320 
A. Greggii, 155, PI. XII 
A. horrida, 173 
A. Koa, 257 
Acanthus, 1S2 
Acer, see also Maple 
A. cireinnatum, 130 
A. glabrum, 120 
A. macrophvllum, 130 
A. Xegundo, 140, 144 
A. platanoides, 47 
A. pseudo-platanus, 47 
Aconitum, Aconite, see also Motik's- 

hood, 37 
Acrocomia, 269, 294, 295, 303 
A. sclerocarpa, 294, 295, Fig. 81 
Acrostichum aureum, 113, 159, 219 
Adansonia, see Baobab 
A. digitate, 164 
Adder-tongue, see Erijthronium, Ophi- 

oglossum 
Adenostoma, 141, 144 
Adhesive seeds and fruits, 16 
Adiantum pedatum, 140 
Aeschynanthus, 209, 212, 238 
Aesculus, see also Horse-chestnut 
Ae. Californica, 141 
Aetoxicum punctatum, 365 
Africa, 157 
Afzelia, 206 
Agapanthus, 30S, 311 
Agathis, see also Kauri, 24, 215, 223, 

248, 336, 338 
A. Australia, 336, 338 
A. Palmerstoni, 248 
Agave, 57, 112, 156,205,303 



Ailanthus, 76 

Alaria, 91, 128 

A. esculenta, 91 

Alaska, 2S, 33, 37-38. St. 128 

Albanv. West Australia, 331 

Alberta, 43 

Albizzia. 173,206,228,314 

A. stipulata. 233 

Aleppo Pine, see Pinus Halept 

Alerce, see Fitzroya 

Aleurites Moluccana, 249, 256, 257, 

PI. XXVI 
Alfalfa, Medicago sativa, 319 
Alfilaria, see Erodium 
Algae, 5, 6, 91-94 

Blue-green Algae, 4, 234 

Brown Algae, 56 

Calcareous Algae, 5 

Coralline Algae, 5 

Red Algae, 56 
Algaroba, see Prosopis 
Algeria, 60-63 
Allamanda, 292 
Allium, 49, 143 
Almond, 52 

Alnus, Alder, 35, 41, 47. 120, 140 
Alocasia, 238 
Aloe, 66, 165, 170, 171, 198, 308, 316, 

318.319. 320, PI. XI. 
A. Schlechteri. 308, Fig. 85 
Alpine vegetation 

Alps. 49 

Atlas, 62 

Carpathians. 49 

Pyrenees, ">ii, 49 

Mt. Rainier, 131 

Rooky Mountains, 31, 120 

Switzerland, 50 

Tyrol. 50 

White Mountains, 31 
Alsophila. 168, L85 
A. erinita, 193 
A. glauca, 206, 228, Fig. 60 
A. ECamarunensis, l( s 
A. pruinosa, 365 
Aistroemeria aurantiaca, ■ 
Altai Mountains. 37. 68 
Amaryllis, Amaryllidaceae, 308 
A. bella-donna. 308 
Amazon. 271, 273, 274, 275, 281 
Amecameca, Mexic 



371 



372 



INDEX 



Amelanehier, 41, 90 

Amorpha canescens, 108 

Ampelopsis, 70. S3 

Anioinum, 20S, 220. 233 

Amorphophallus, 207, 233 

A. Titanum, 207 

Andes, 282, 283, 284, 286 

Andromeda, 37, 95, 101 

Andiopogon, 163, 172. 243, 318, 357 

Anemia phvllitidis, 294 

Anemone, 30, 33, 37, 41, 45, 53, 80, 

87, 93, 108. 240 
A. nemorosa, 50 
Anemotheca, 316 
Angelica, 38 
Angiopteris, 216, 221, 244, 253, Fig. 

64 
Angiosperms, 9 
Angola, 165 
Angophora, 332 
Angraecum, 168, 195 
A. eburneum, 199 
Anigozanthus, 330, Fig. 90 
Annam, 196 
Anonaceae, see also Custard Apple, 

228 
Ansella Africana, 172 
Antarctic Continent, 13, 23 
Ant. beech, see Nothofagus 
Ant. fossils, 350 
Antiaria toxicaria, 228 
Anthurium, 278, 295, 298 
Antilles, 301 
Apocynaceae, 288, 292 
Aponogeton distachya, 313 
Appalachian Mountains, 84, 96 
Apricot, 197 

Aquilegia, see also Columbine 
A. formosa, 42 
A. coerulea, 115 
Araceae, Arum, Aroid, 1, 72, 113, 

162, 185, 207, 214, 215, 219, 220, 

228, 244, 258, 277, 278, 290, 298, 

303, 365, 367 
Aralia, 72, 176, 177 
Aral Sea, 37 
Arakan Mountains, 94 
Araucaria, 9, 24, 51, 322, 325, 333, 

339 
A. Bidwillii, 322, PI. XLI 
A. Cunninghamii, 325 
A. excelsa, 325 
A. imbricata, 363, 369 
Arbutus, 53, 56 
A. Menziesii, 132 
Arbor Vitae, see also Thuya, 90, Fig. 

17 
Giant A., 119, 130, Fig. 29 



Archangelica, 33 

Archontophoenix, 244, 245, PI. XII, 

Fig. 60 
A. Cunninghamiana, 244 
A. Alexandrae, 245 
Arctic Zone, 23, 26, 27 
Arcto-Tertiary Flora, 27 
Arctotis, 309 
Arctostaphylos, see also Menzanita, 

138, 146 
A. Uva-ursi, 90 
Areca, 182, 192, 196, 201, 228, 237, 

246, 325 
A. Catechu, PI. XVII 
Arenga, 201, 237 
Arenaria, 42 
Arethusa, 95 
Argentina, 274, 355, 356, 357, 358, 

369 
Aristida stipoides, 172, 174 
Aristotelia, 346, 365, 369 
A. racemosa, 346 
Aristolochia, 361 
A. Chilensis, 361 
Arizona, 85, 153-156, 263 
Arrow-head, see Sagittaria 
Arrow-root, (Maranta, Marantaceae,) 

277 292 
Artemisia, 68, 108, 122, 124 
A. frigida, 41 
Artocarpus, Artocarpaceae, 206, 215, 

218, 237, 279 
Arundina speciosa, 215, 220 
Asclepiadaceae, see also Milkweed, 

314, 320 
Asclepias, 108 
Ascophyllum nodosum, 91 
Ash, see also Fraxinus, 47, 49, 62, 70, 

92, 103, 269 
Asia, 157, 176 
Asia Minor, 52, 66, 67 
Asparagus, 1, 170, 316 
A. plumosa, 316 
Aspen, see also Poplar, 41, 43, 106, 

109 
Aspidium munitum, 140 
Asplenium, 120, 205, 229 
A. filix-foemina, 120 
A. Nidus, 205, 229 
Aster, 41,94, 109-115, 120 
Astelia, 339, 347, 350, 359 
A. Solanderi, 339 
Astragalus, 42, 64, 108, 109 
Astrocaryum, 288 
Athabaska, Lake, 43 
Atlantic Islands, 65 
Atlantic North America, 84 
Atlas Mountains, 60, 61, 62 



INDIA 



37 ! 



Atlas cedar, G2, 63, Fig. 11 

Atlin, Lake, 42, 43 

Atriplex, 144, 300, 32S 

Attalea, 288, 294, 296, Fig. SO 

Aucuba, 74 

Australia, 13, 14, 213, 242, 320, 351, 

354 
Australasia, 349 
Austria, 47 

Avicennia, 159, 182, 288, 300, 314 
A. nitida, 159, 188 
A. officinalis, 182, 300, 314 
Azara, 361 
Azalea, see also Rhododendron, 68, 76, 

78,83,90,98,101, 145,240 
A. calendulacea, 98 

A. occidentalis, 145, Fig. 40 
Azederachta Indica, 181 
Azorella glebaria, 358 
Azores, 52, 65 

Babiana, 307, 308, 321 

Babinda, Australia, 323 

Baccharis, 266, 361, 365 

Diiotfri^ 4 

Bactris, 269, 280, 288, 303 

Bacularia, 245 

Baguio, Philippine Islands, 239 

Bahia, 361 

Baikal, Lake, 37 

Baikeaea plurijuga, 174 

Balanophora elongata, 231 

Balata, see Mimusops 

Balanocarpus, 206 

Bald cypress, see Taxodium 

Balearic Islands, 59 

Bali, 234 

Balkans, 48, 67 

Balsamodendron, 177 

Balsam fir, see also Abies, 89 

Bamboo, 72, 81, 163, 190, 268, 286, 

PI. XVI 
Banana, see also Musa, 58, 72, 79, 

197, 208 
Banajao Mt., Philippine Islands, 236, 

238 
Bandar Baroe, Sumatra, 219 
Banksia, 327, 329, 330, 333 

B. grandis, 329, 330, Figs. 89, 90 
Banksia rose, 78 

Banyan, see also Ficus, 181, 229 
Baobab, see also Adansonio, 164, 169, 

173, Fig. 50 
Barley, 67 

Barringtonia, 217, 234, 236, 314 
B. speciosa, 217, 234 
Basswood, see Tilia 
Batavia, Java, 226 



Bates. H. W .-no 

Bauhinia, 173, 17 1, 204, 206, 287, -'7'' 

Bay, sec I 'lulu Uularia 
Beach morning-glory, Bee / pnmoea 
Beach pea, see Lathyrus 
Bear-berry, Bee .1 n tostaphylos 

Beccari, 21 1 
Beckera, 163 

Beech, see also Fagtu, Nothofag 
11, 26, 35, 15, 17. is. 59, 81, * 

89, 93, 96, 99, PI. IX 
Begonia, 168, 209, 214, 221, 223, 2:38, 

239,240 
Behring Sea, 32 
Bella Sombra, 57 
Bellenden Ker Mountains, Australia, 

243, 323 
Bengal, Bay of, 70 
Berberis-Barberry, 48 
B. repens, 119 
B. Darwinii, 369 

Bertholletia excelsa, see Brazil-nut 
Betel palm, see Areca 
Bigelovia, 123 
Bignonia, Bignoniaceae, 100, 185, 

275, 282, 37,7,. 356, 367 
B. venusta, 355, 367 
Birch, Betula, 23, 28, 30, 35, 37, 41, 

45, 70, 72, 90, 92, 96, 106, 120 
Canoe, B., 106 
Birch steppe, 37 
Yellow B., B. lutea, 89 
Birds, agents in distribution, 16, 

255 
Bird-cherry, see Prunus 
Black Alder, see Ilex 
Black Forest, 47 
Black Walnut, see Juglans 
Bladder Kelp, see MaarocyatiSi -V- 

ocystis 
Bleeding heart, see Dieentra 
Blister rust, 21 
Bloodroot, see also Sanguinarui, 87, 

93 
Bloomeria, 141 
Bluebell, Scilla nutans, 7.1 
Blue Mountains, Jamaica, 301, 304, 

307 
Blue Nile, 169 

Blue Valerian. Bee Pol* monivm 
Bombax, Bombacaceae, L62, 191,24 

276,280, 282, 303 
B. Malabaricum, 191 
Borassus. 169. L95, 2 17, 
B. flabelliformis, 169, 182, 1'ig 
Boron ia, .127. ;!■!<» 
Borneo, 210 218 
Boswellia, 177 



374 



INDEX 



Botanical Gardens 

Buitenzorg, Java, 226 

Calcutta, 181 

Singapore, 206 

Peradeniya, Ceylon, 191 

Trinidad, 294 
Bougainvillea, 52, 283, 355 
Bouteloa oligostachya, 108 
Bowenia, 249 

Bracken, see also Pteridium, 47, 290 
Bramble, see also Raspberry, Rubus, 

98 286 
Brazil, 271-283, 355, 357, 369 
Brazil Nut, 274, 275, 276, 280 
Brevoortia, 141 
British Columbia, 41, 121, 130 
British Islands, 51 

Broom, see also Cytisus, 20, 45, 48, 53, 
59, 66, 349 

Spanish B., see Spartium 
Brugmansia, 223 
Bryanthus, 131 

Bryophyte, see Liverwort, Moss 
Buckbean, see Menyanthes 
Buckeye, see Aesculus 
Buck-thorn, see Rhamnus 
Buddleia, 72 

Buffalo berry, see Shepherdia 
Buffalo grass, Buchloe dactyloides, 

108 
Bugamia, 274 
Bunch grass, see also Tussock grass, 

106, 108 
Burkea, 173, 319 

B. Africana, 319 
Burma, 185, 194 

Buttercup, see also Ranunculus, 24 

28, 45, 50, 93, 240, 343 
Butterfly pea, see Clitoria 
Butterfly tulip, see Calochortus 
Butterwort, see Pinguicula 
Button-bush, see Cephalanthus 

Caatinga, 273, 274, 282 
Cabbage-Palmetto, see Sabal 

C. palm, see Oreodoxa 
C. tree, see Cordyline 
Cacoucia coccinea, 275 

Cacti, 52, 106, 112, 152, 156, 198, 264, 
265, 267, 283, 300, 303, 320, 357, 
359, 367 

Caesalpinia bonducella, 159 

Caesalpineae, 279 

Cakile maritima, 94 

Caladenia, 329 

Caladium, 282 

Calamus, 202 

Calandrinia, 361, 366, 367 



Calceolaria, 286, 361, 369 
Calcutta, 181 

California, 85, 132, 139, 142, 263 
Calla, Calla-lily, 52, 307, 313, 354 
Callistemon, 331 
Callitris, 61, 313, 334 
C. cupressoides, 317 
C. quadrivalvis, 61 
Calluna vulgaris, 47 
Calochortus, 123, 143 
Calophyllum, 206, 236, 257 
Calopogon, 95 

Caltha palustris, see also Marsh- 
marigold, 36, 143, 367 
Calycanthus, 146 
Calypso borealis, 36 
Calystegia, 300 
Camassia esculenta, 109, 148 
Camellia, 73, 74, 185 
Campanula, 50, 109, 170 
C. rotundifolia, 109 
Canada, 29, 33, 84, 85, 88, 89, 116 
Canary Islands, 52, 65, 66 
Canary Is. date, 66 
Canary nut, Canarium, 228 
Candollea, Candolleaceae, 329, 334, 
351 

Canna, 113, 162, 270, 278, 282, 290 
C. Indica, 162, 292 

Cannon-ball tree, see Couropita 

Canterbury Plain, New Zealand, 336, 
343 

Caper, Capparis, 64 

Cape Region, South Africa, 307, 308- 
312 

Cape-weed, see Cryptostemma 

Carapa, 182 

Carboniferous, 3, 8 

Carcross, British Columbia, 42 

Cardamine, 140 

Cardoon, see Cynara 

Carissa, 172, 307, 314 

C. edulis, 172 

C. ferox, 307, Fig. 83 

Carlinia, 49 

Carludovica, 277 

Carmichaelia, 345 

Carob, see Ceratonia 

Carpathian Mountains, 46, 48 

Carpentaria, 144, 146 

C. Calif ornica, 146 

Carya, see also Hickory 

C. microcarpa, 106 

C. alba, 106 

Caryota, 202, 205, 207, 221, 228, 245, 
325, Fig. 59 

C. urens, 202, 325 

Cascade Mountains, 123, 124, 132 



INDEX 



375 



Cascara, Bee Rkammu 

Caspian Sea, 37, 68 

Cassia, 64, L72, 174, 189, 228, 233, 

275, 279, 281, 318, 359 
C. fistula, 172 
( Sassiope, 30 
C. tetragona, 30 
Castanea, Bee also Chestnut 
C. vesca, 47 
C. dentata, 91 
Castanopsis, 146 

Castilleia, 109, 115, 120. 131, 138, 286 
Cassytha filiformis, 159, 310 
Casuarina, 16, 24, 198, 217, 234, 235, 

257, 328, 330, 334 
C. equisetifolia, 234 
Catalpa, 74 
Catha, 170 
Cat-tail, see Typha 
Cattleya, 286 

Ceanothus, 137, 138, 146, 150 
Cedar, see Cedrus, Juniperus, Cham- 

aecyparis, Thuya 
Cecropia, 280, 287, 288 
C. palmata, PL XXXI 
Cedrus Atlantica, 62, 63, Fig. 11 
C. Deodara, 70 
C. Libani, 51 
Cedar swamps, 101 
Cedrela, 184, 230, 280, 303 
C. odorata, 295 

C. Toona, 184, 247, 248, PI. XXIII 
Cereus, 155, 361 
C. giganteus, PI. XII 
Ceiba, 162, 290, 303, 380 
C. pentandra, 290, 299, PI. XXXVI 
Celastrus, 76 
Celmisia, 345, 349, 352 
C. Lindsayi, 352, Fig. 99 
Celtis, see also Hackberry, 93, 230, 316 
Centaurea, 48 
Central Africa, 171 
Central America, 269, 286 
Central Europe, 46 
Century plant, see also Agave, 52 
Cephalanthera, 150 
Cephalanthus, 144 
Cephalotaxus, 76 
Cephalotus, 332 
Ceratopteris, 113 
Ceropegia, 193 
Cetraria, 33 
C. cucullata, 33 
C. Islandica, 33 
Ceylon, 178-190, 193 
Chaetobromus, 163 
Chamaebatia, 144 
Chamaecyparis, 101, 128, 150 



Chamaecyparia Lawsoniana, 150 
( '. Nootkatensis, 128 

< '. thuyoides, Ml 
( ihamaedoria, 268 
Chamaerops, "»:;, 61 
C. humilis, 53, 61, Fig 

Chaparral, 116, 117, lis, 125, 146 
Characeae, •"», 94 
Cheilanthes, 172 

( Jhenopodium, 2S6 
Cheripunji, India, 178 
Christchurch, New Zealand 343 

Cherry, see also Primus, 43, 47, 48, 

72, 81, 90, 93, 98 
Chestnut, 21, 35, 47, 48, 56, 91, 96, 
230 

C. blight, 21 
Chicago, 22, 106 

Climate of, 22 

Prairies of, 106 
Chickweed, 72, 386 
Chicl, 288 
Chile, 259-367 

Oceanic islands of, 370 
Chimaphila, 36, 119 
Chinquapin, 146 
China, 74, 76 
Chrysophyllum, 113 
Chlorogalum, 143 
Chorizema, 332 
Chuzenji, Japan, 81 
Cinchona, 224, 279, 284, 286 
C. succirubra, 284 
Cinnamomum, 78, 237 
C. camphora, 78 
Cinnamon fern, see Osmunda 
Cinquefoil, see Potent ilia 
Cissus, 168 
Cistus, 53, 59, 60 
C. Monspeliensis, Fig. 10 
Citrullus, 64, 320 
C. colocynthus, 64 
C. vulgaris, 320 
Cladium effusum, 110 
Clark ia. 14 2 
Claytonia, 32, 150 
Clematis, 49, 93. 100, 168. 170 
Clerodendron, 161, 168, 172, 221 
C. splendens, 161 
Clethra, 101. 303 
C. alnifolia, 101 
Cliathus Dampieri, 329 
Clitoria. 292 
Clove, 197,235 
Clover, 1 
Club-moss, see also bycopod, Li/copo- 

dineae, 8, 35, 24 
Clusia, 296 



376 



IXDEX 



Coastal Plain. Eastern United States, 

90. 100. 102 
Coconut. Cocos. 16. 113. 164. 1S9. 

211.234.23.5. 253. 313.355 
C. datil. 335 
C. plumosa. 335 
Coelogyne. 193. 220 
Coffee. Coffea. 172. 224 
C. Arabica. 177 
C. Engleri. 172 
Colchicum. 64 
Coleus. II - 

Colocasia antiquorum, 25S 
Colocvnth. see Citrul. 
Colombia. 283, 28 
Colombo. IS 
Colorado. 115. 116 
Colorado Desert. 144. 154. Fig. 48 
Colpoon. 172 
Columbia River. 123 
Columbine, see also Aquilegiu, 42. 49. 

115. 150 
Combretum, Combretaceae. 159. 269. 

275. 314 
Comianthus. 274 
Compositae. 49. 59. 105. 222. 234. 25 - 

266, 269. 292. 307. 311. 349, 358 
Comptonia. 101 
Congo, 165 
Conifer. Coniferae. 9. 10. 74. 119. 138. 

215. 325. 359. 363 
Conocarpus erectus. 159 
Continental Divide. 116 
Convolvulus. 64. 70 
C. Mauretanicus, 64 
Cook's Strait. 343 
Copaifera. 173. 174 
C. coleosperma. 173 
Coprosma. 339. 346 
Coral Islands. 249. 2.50 
Coral-root, Corallorrhiza, 36, 119 
Corallines, see Algae 
Cordaitales, 8 
Cordillera. So 
Cordyline, 338, 341 
Corea. 74 
Coreopsis. 108 
Cork oak, see also Quercus suber, 57. 

59.64 
Cotyledon. 42, 309, 311 
C. haemisphericum. Fig. 5S 
Cornel, Cornus, 36. 41. 119. 128, 130, 

14 
C. Canadensis. 90. 41 
C. Florida. 98 
C. Xuttallii, 130. 1 
C. Suecica. 36 
Corn-flower, see Centaurea 



Corsica. 59 

Corypha, 191, 192 

C. umbra culif era. PI. XVII 

Costa Rica. 269 

Costus. 208, 220. 275. 292 

Cotoneaster. 72 

Cotopaxi. Mt.. 254 

Cotton. 55. 157 

Cotton-grass, see also Eriophorum, 

30. 42. 50 
Cotton-wood, see also Poplar, Popu- 

lus. 109. 116. US. 140 
Couropita Guianensi-. 296, Fig. 92 
Cranberry, see also Yaccinium, 2S. 95 
Crataegus, see also Hawthorn. [ v 
Creosote bush, see Larrea 
Cretaceous. 6. 9. 10 
Crete, 59 
Crinum. 113. 166 
Croton. 170 
Cryptomeria. 76, SI. 52 
C. Japonica. PI. VII 
Crypt ostemma calendulaeea. 355 
Cucumber tree, see Magnolia 
Cunonia. Cunoniaceae, 311 
C. Capensis. 311 
Cupr ess a 13S. 313 
C. macrocarpa, 13S. 316 
Curcuma. 233 

Currant, see also Ribes. 92, 118 
Custard Apple, see also Sapotaceae 
Cyanea. 252. 258 
C. coriacea. Fig. 72 
Cvcad, Cvcadales, 9, 10, 110, 249 
Cycas. 78, 249. 331 
Cyclanthaceae. 277 
Cynara cardunculus. 357 
Cynoglossum. 140, 169 
Cvperus, 162 
C. Papyrus. 162 
Caress, see also Cupressus, Taxo- 

diunu 53. 103. 112. 139 
Cyprus, 69 

Cvpripedium. 42. 50. 95. 239 
C.Argus. Fig. -i _ 
C. calceolus. 50 

C. spectabile, 95 
Cyrtostachys lacca, 202 
Cytisus, see also Broom, 48, 59 

Dacrvdium, 207. 215, 238, 334, 366 

D. cupressinum. 338, 346 
Dakota. 108 
Dalbergia. 154 
Dammar gum, 222 
Dampiera. 329 
Danaea, 296 
Dandelion, 49 



IND] 



377 



Danthonia, 142 

Daphne. 51, 

D. cneorum. .51 

Darlingtonia, 146, 151 

D. Californica. Fiji. 45 

Darjiling. 7' 72 

Date palm, see al- 57. 58, 

64, 65, 66, 67, 160, Fig. 12 
Dawsonia superba. 347. Fig. 96 
Death Valley, 135. 143. 144. Fig. 39 
Deecan. India. 178> 1S6 
Dempo. Mt.. Sumatra. 223 
Dendrobium. 72, 80. 193. 216. 231, 

240 
D. crumenatum. 216 
D. secundum. 223 
Dendroealamus. 190. 2_^ 
D. giganteus. 190. 191. 207. PI. XVI 
Dendromecon, 141 
Dentaria. 92 

Deodar cedar, see also Cedrus, 70 
Deserts. 
Arabia. 177 

Australia. 327. 32S. 329 
Colorado. 152 
Mojave, 12-5. 134. 144 
Mesopotamia. 66 
Mongolia. 7 

25. 65. L58 
S nora, _ 
Utah. 121 
Desmodium. 108 
Desmoncus. 277. 281 
Deutzia. 74. 81 
Devil's club, see also Echinopanax, 

40. 120. 129, Fig. 6 
Devonian. 7, v 
Dhak. see Butea 
Dianthus. 48, 170 
Diapensia Lapponica, 31 
Diatoms. 6 
Dicentra. 78 2. 1.50 
Dicksonia. 3 
Dicotyledons, 49 
Didymocarpus. 214. 221 
Disser-pine. Pinus Sabiniana. 146 
Digitalis, see Foxglove 
Dillenia. Dilleniaceae. 218, 230 
Dimorphotheca, 209 
Dionaea muscipula. 101 
Di< 

Dipteri<. 216 
Dipterocarp, Dipterocarpaceae. 1 - 

_ 5, 214. 21s. 222. 228, 235,243 
Dipterocarpu- _ 
Disa. 17 
Disperis. 30S 
Distribution. Factors in. 15 



Diun 

Dock. Bee also Rum* 
Dodecatheon. 32, 33, 92, 1 I 
Dogwood, see also Benthamw, Cornus 

'--'- 100, 130 

Dolomites, 50 
Dombeva. 170. 172. 17 
D. Natali 

Dom-palm. see Hyphaene 
Doryanthes excelsa. 327 
Douglas fir. see aN tsuga, 51. 

115. 117. 119, 129, 130, 139, 

1.50 
Draba. 30 
Dracaena, 66. 257 
D. draco. 66 
Dracophyllum. 345. 1 
D. arboreum. 3 

D. Traversii. 345. | 97 

Drepaninidae. 257 
Drimvs. 3-50. 365. 366, 369 
D. Winteri 
Drosera. see also Sundew, 36, 96, 290, 

307 
Dryas. 31. 

D. octopetala. 31. 120 
Duabonea sonneratioides. 71. PI. Ill 
Dune-. 105. 137 
Durban. 312. 313 
Durian. Dur: 1 201, 204 

D. zibethinus. 204 

East Asia, 74 

Canada and United States. 88 
•• Central Africa. 169 
• Java. 233 
Ebony, Ebenaceae _ _ 
Echinopanax. see also Deiii's club, 
40 

E. horrida. 40. Fig. 6 

Edelw j Leontopodium 

E iible frui* - 

-etia. 
Elaeis. see also Oil palm, 160 
E. Guieneen<:-. 160 
Elaeocarpu- 198,2 
Elder, see also <S 

11 
Eletteria. 220. ] _ 
Elm. see - ' " 70, 8 

85, 89 I . ' _ 

renari - 
bothriur. _ - 
Empetrur: 
Enceh 
Encephalartos. 316 



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LIBRARY 









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378 



INDEX 



Endemism, 
Hawaii, 257 
Juan Fernandez, 370 
Engelmann Spruce, see Picea 
Englcr. A., 318 
Enkianthus, 74 
Eocene, 3, 10 
Epacridaceae, 344, 349 
Ephedra, 156 
Epidendrum, 113 
Epigaea. 7, 83, 90 
E. Asiatica, 83 
E. repens, 83, 90 
Epilobium, 41, 42 
E. angustifolium, 41 
E. latifolium, 120 
Epipactis, 151 

Epiphytes, 212, 214, 228, 230, 249, 
277, 300, 347 
Ferns, Fig. 80 
Figs, 161, 207 
Rhododendron, 209 
Equatorial West Africa, 159 
Equisetum, 35, 40, 129, 284 
E. giganteum, 305 
E. telmateia, 129 

Erica, Ericaceae, see also Heath, 59, 
90, 98, 223, 266 

Erigeron, 49, 120, 138 

Eriocaulaceae, 290 

Eriodictvon, 146 

Erodium, 21, 361 

E. cicutarium, 361 

Ervthrina, 168, 172, 313, 319 

E. Caffra, 313, 319 

E. excelsa, 168 

Erythronium, 116, 131, 140 

E. grandiflorum, 116 

E. montanum, 131, Fig. 35 

Erythroxylon, 187 

Escallonia, 365, 369 

Eschscholtzia, 138, 142, 144 

E. Californica, 142 

Eucalyptus, 24, 25, 57, 235, 326, 327, 
330,332,349,351,353 

E. diversicolor, 332 

E. ficifolia, 332 

E. regnans, 326, 327, PI. XLIII 

Eucalysta, 274 

Eucharidium, 144 

Eugenia, 113, 189, 206, 228, 239, 249, 
257, 280, 363 

E. Malaccensis, 257 

Eupatorium, 94, 266, 361 

Euphorbia, 66, 144, 165, 171, 172, 174, 
180, 181, 198. 266, 308, 312, 318, 
320. PI. XXXIX 

E. fulya, Fig. 77 



Euphorbia grandidens, 316 

E. Mauretanica, 307 
Euphorbiaceae, 162, 218, 280, 365 
Everglades, 110 

Exacum, 193 

Fabiana, 369 
Fagus, see also Beech 

F. sylvatica, 47 
Falkland Islands, 358 

False Hellebore, see Veratrum 
Ferns, 9, 15, 72, 73, 76, 113, 168, 198, 

203, 207, 228, 230, 234, 237, 

260, 284, 294, 334, 339, 346, 365, 

370 
Fern steppe, 370 

Filmy ferns, see Hymenophyllaceae 
Tree-ferns, see Tree-fern 
Festuca Novae Zevlandeae, 336 
Ficus, Fig, 113, 170, 172, 175, 181, 

182, 206, 230, 233, 237, 243, 277, 

279, 314 
F. Bengalensis, Fig. 54 
F. Benjamina, PI. XX 
F. cordata, 319 
F. religiosa, 182 
F. sycamora, 64, 170, 172 
Fiji, 249 

Filaree, see Erodium 
Fir, see also Abies, 9, 24, 26, 34, 43, 45, 

46, 58, 67, 70, 81, 89, 92, 115, 119, 

122, 147, 266 
Fire-weed, see Epilobium 
Fitzroya, 360, 366, 369, PI. L 
F. Patagonica, 366 
Flacourtia, 187, 206, 230 
Flagellaria, 159 
Flagellata, 5 

Flame Azalea, see A. calendulacea 
Flax, see also Phormium, 65, 108 
Flindersia, 248 
Florida, 84, 86, 102, 103, 110, 111, 

112,301 
Flotowia, 365 
Flourensia, 261 
Forbes, H. O., 222 
Forget-me-not, 50 
Formosa, 241 
Forsythia, 76 
Fossils, 2, 3 
Fouquiera, 152, 156 
F. splendens, Fig. 46 
Foxglove, 20, 45 
Fragaria, 138, 191, 369 
F. Chilensis, 138, 369 
Franseria dumosa, 144 
Franz Josef Land, 28 
Fraxinus, see also Ash, 47, 103 



INDEX 



379 



Fraxinus elatior, 47 

F. ornus, 49 

F. platvcarpa, 103 

Frcesia, 321 

Fremont iaCalifornica, 146 

Fresno, SS 

Frevcinetia, 221, 257 

F. Arnottii, 257 

Fritillaria, Fritillary, 68, 109, 116, 

140 
F. pudica, 116 
Fuchsia, 286, 343, 350, 361, 365, 369 

F. excorticata, 343 
Fucus, 91 
Fuegia, 358, 359 

Fuegian flora, 334, 349, 351, 359 
Fungi, 7, 21 

Gaillardia, 109, 150 

G. aristata, 109 
Galapagos Islands, 300 
Galium, 169 
Gangetic Plain, 181 
Ganges, 178 

Gapo, 271, 273, 275, 288 

Garcinia, 204 

G. mangostana, 204 

Gardenia, 81, 257, 314 

Garrya, 141 

Gastrolobium, 332 

Gaultheria, 90, 191, 232, 240, 345, 

366 
G. procumbens, 90, 232 
Gazania, 307, 309, 314 
Gedeh, Mt., Java, 231, 232 
Gelsemium, 99 
Genista, 59 
Gentian, Gentiana, 42, 49, 50, 51, 

116, 120, 191,353 
G. acaulis, 49, 51 
G. corymbifera, 353, Fig. 100 
G. verna, 49 
Geological climates, 3, 4 
Geonoma, 269 

Geranium, 37, 48, 52, 72, 93, 170, 286 
Gerbera, 170 
Gesneraceae, 214, 277 
Geum, 31, 42 
Ghats, India, 178, 186 
Giant arbor vitae, see Thuya plicata 
Giant bamboo, see Dendrocalamus 
Giant gum, see Eucalyptus 
Giant Kelps, 39, 128 
Gigantochloa, 228 
Gigartina, 136 
Gilia, 144 
Ginger, see also Zingiber acme, 1, 233, 

270 



Ginkgo, 9, 76, 77, Fig. If; 

( rlaciers, 1. 8 

( rlacial epoch, 11, 27 

Glacial lake 94, 95, Fig. I 

Glacier National Park, 109, 1 17 

Gladiolus, 53, 64, 170. 307, 308, 117, 

323 
Gleditschia, 68, 76, 
Gleichenia, 202, 207, 209, 212, 232, 

239,311,367 
G. arachnoides, 232 
G. dichotoma (linearis), 202, Fig. 57 
G. polypodioides, 311 
Globba, 208 
Glossopteris, 8 
Gnaphalium, 191, 240 
Gnetaceae, 166 
Godetia, 142 
Goldenrod, see also Solidago, 42, 93, 

109 
Golden shower, see Cassia fistu'a 
Gondwana Land, 8, 15 
Goodenia, Goodeniaceae, 329, 334, 

351 
Goodyera, 36 

Gooseberry, see also Ribes, 93 
Gordonia, 72. 184, 203, 230 
G. excelsa, 203, 330 
G. Wallichii, 184 
Gorse, 47, 354 
Gouldia, 258 

Grama grass, see Bouteloa 
Gramineae, see Grass 
Grape, see also Vine, Vilis, 67, 83, 

93, 100 
Grasses, 63, 108, 123, 142. 163, 234, 

243, 266, 276, 2st>, 290, 301), 309, 

318, 327, 389 
Grass of Parnassus, sec ParnaMSia 
Grass tree, see Xanthorrhoea 
Great Basin, 121, 122 
Great Kamerun, Mt., 166 
Great Lakes, 84, 85, 88, 92 
Great Salt Lake, 85 
Great Valley of California, 112 
Grease-wood, see Sarcobattu 
Greenland, 28, 29, 33 
Grevillea, 25, 248, 326, 330, 332, 349 
G. robust a, 248, 332 
Grewia cana, 317, Fig. 33 
( rrindelia, 366 
( Iriselinia Littoralis, :; is 
Groo-groo, sec Acrocomia dderocarpa 
Grubbia,311 
Guayacum, 113 
( riiatemala, 20'.' 
( luava, sec Pndiwn 
Guianas, 283, 286 



:;so 



INDEX 



Gulf of Mexico, Gulf region, 84, 102, 

103 
Gulielma speciosa, 280 
Gum, see also Eucalyptus, Liquidam- 

bar, Nyssa, 27, 87, 313 
Gunnera, 25S. 346, 365, 366 
G. Chilensis, 366 
G. manieata, 366 
G. petaloidea, 258, Fig. 73 
Gymnosperms, 9 
Gynerium, 286 
G. saccharoides, 286 
Gypsophila, 57 

Habenaria, 148, 170 

H. leucostachys, 148 

Hackberry, see Celtis 

Haemanthus, 170, 316 

Haematoxvlon, 303 

Haiti, 301 

Hakea, 330 

Haifa grass, see Stipa 

Halophytes, 300 

Hamamelis, 76, 98 

H. Virginica, 98 

Hammock (Florida), 112, 113, PI. X 

Harz Mountains, 46 

Hau, see Hibiscus tiliaceus 

Hawaii, Hawaiian Islands, 249, 250, 

252, 255, 260, 261 
Endemism, 258 
Origin of flora, 261 
Hawkweed, see Hieracium 
Hawthorn, see also Crataegus, 47, 48, 

51 
Hazel, 48 
Heath, Heath family, see also 

Ericaceae, 45, 47, 66, 90, 310, 

311,321 
Hedyotis, 193 
Helichrysum, 311 
Heliconia, 282, 285, 291, 296, 303, 

PI. XXX 
H. bihai, 296 
Heliotropium, 318 
Helminthostachys Zeylanica, 189 
Hemerocallis, 37 
Hemitelia, 311,314,346 
H. Capensis, 311, 314 
H. Smithii, 346 
Hemizonia, 144 
Hemlock, see also Tsuga, 83, 92, 

139 
Hepatica, 36, 50, 93 
Hepaticae, see Liverwort 
Heracleum, 37, 38, 119 
H. barbatum, 37 
H. lanatum, 37 



Hevea Braziliensis, 201, 205, 280, 

Fig. 59 
Hexe Valley, South Africa, 321 
Hibiscus, 94, 95, 217, 233, 253 
H. moscheutos, 95 
H. tiliaceus, 217, 233, 253 
Hickory, see also Carya, 11, 87, 92, 

103, 105, 106 
Hieracium, 34, 50 
High Veldt, South Africa, 317, 318, 

Fig. 86 
Himalaya Mountains, Himalayan 

region, 68-75, 184, 185 
Hokkaido, Japan, 78, 83 
Holarctic, 26 
Holly, see also Ilex, 62 
Honduras, 269 
Honey-locust, see Gleditschia 
Honeysuckle, 43, 45, 98 
Hood, Mt, 85 
Hopea, 222 

H. dryobalanoides, 222 
Hornbeam, see also Carpinus, Ostrya, 

106 
Horse-chestnut, 70 
Horse-mint, see Monarda 
Horse-tail, see Equisetum 
Houstonia, 279 
Houttuynia, 80 
Huckleberry, see also V actinium, 39, 

47, 87, 90, 101, 129, 286 
Hungarian Plain, 48 
Hunnemannia, 172 
Hura crepitans, 280, 290, 275 
Hydrangea, 72, 76 
Hymenocallis, 103, 113 
Hymenophvllaceae, 193, 207, 221, 

238,296,311,334,346 
Hypericum, 169, 170, 187, 191 
Hyphaene, 169, 174, 314 
H. crinita, 314 
H. Thebaica, 169 

Iberian Peninsula, 54-57 

Iceland, 28, 29, 46 

Iceland poppy, see Papaver-nudicaule 

Idaho, 121 

Idria columnaris, 267, PL XXVIII 

Ilex, 101, 355 

I. Paraguayensis, 355 

I. verticillata, 101 

Ilex-oak, see Quercus Ilex 

Illinois, 93 ' 

Impatiens, 221, 230 

Imperata arundinacea, 221, 243 

Imperial Valley, 151 

Incense-cedar, see Libocedrus 

India, 177-188 



INDEX 



.,-1 



Indian-pipe, sop Monotropa 
Indigo, 181 

Indigofera, 318 

Indo-China, 195-197 

Inga, 274, 275, 279, 288 

Iowa, 108 

Ipomoea, 112, 168, 185, 204, 218, 

300 
I. pes-caprae, 112, 216, 236, 267 
Irrawadday River, 194, 196 
Iriartia ventricosa, 269, 284 
Iridaceae, 143, 316, 354 
Iridea, 136 

Iris, 53, 64, 68, 103, 143 
I. cuprea, 103 
I. hexagona, 103 
Iron-weed, see Vernonia 
Italy, 53 
Ixia, 321, 354 
Ixora, 191,214 
I. coccinea, 191 

Jacaranda, 355 

Jack-fruit, Artocarpus integrifolia, 

215 
Jacksonia, 332 
Japan, 78-83 

Gardens, 81 
Java, 25, 224-234, 241 

East Java, 233 
Juana Australis, 370 
Juan Fernandez, 370 
Jubaea spectabilis, 363, 370 
Juglans, see also Walnut, 53, 68, 

106 
J. cinerea, 108 
J. nigra, 53, 106 
J. regia, 68 

Jujube, see also Zizyphus, 171 
Juniper, Juniperus, 30, 44, 93, 122, 

171 
J. nanus, 41 
J. occidentalis, 149 
J. Virginiana, 90 

Kadiak Island, 38 

Kaffir-boom, see Erythrina Caflra 

Kalahari desert, 306, 307, 320 

Kalmia, 45, 90, 98 

K. glauca, 33 

K. latifolia, 98 

Kameel-dorn, see Acacia giraffae 

Kamerun, 165 

Kamtchatka, 37, 38, 80 

Kangaroo-paws, see Anigozanthus 

Kansas, 108 

Kapok, 280 

Karroo, 306, 307, 320 



Kan Hills, India, 178 
Kauai, Hawaii, 267 
ECaulfussia-Christensenia, 216 

Kauri. :]><> Agatl ■ 2 

248,341 
Kelp, 39, mi. 128 
Keys [Florida), 301 
Kidney-fern, see Trichomanea reni- 

forme 
Kigelia, 16 

Kina-balu, Mount, Borneo, 210 
King-cup, see Troll in* 
Kinsgley, Mary, 161 
Kingston, Jamaica, 301, 302 
Knightia excelsa, 342 
Kniphofia, 316 

Knysna Forest, South Africa, 306 
Kochia, 328 

Kohala Mountains, Hawaii, 259 
Koeleria, 108 
Krakatau, 233, 234, 260 
Kuching, Borneo, 212 
Kukui, see Aleurites 

Labiatae, 59, 269 
Labrador, 43, 44 
Lady-fern, see Asplenium filii-joe- 

mina 
Lady's slipper, see Cypripedium 
Ladysmith, South Africa, 315 
Lagerstroemia, 198, 204 
Laguncularia racemosa, 159 
Lalang grass, 221, 238 
Laminaria, Laminariaceae, 91 
Landolphia, 161 

Lanuto, Lake, Samoa, 251, PI. XXIV 
Lapageria rosea, 370 
Laportea, 249 
L. gigas, 249 
L. moroides, 24!) 
Larch, Larix, 33, 37, 45, 70, 71. 

117,119 
L. Americana, 43, 92 
L. occidentalis. 117, 119, Fig. 27 
Larkspur, 37, 108, 116, 120, 140 
Larrea, 144, 151, 156,367 
L. Mexicana, 144 
Lathyrus, 95 
L. maritimus, 95 
Lauraceae, Laurel, Lauras, 27, 

56,62,66, 113, 269, 365 
Laurelia, 349, 365 
L. aromatica, 365 
Laurestinus, Bee Viburnum (inus 
Lavatera, 57 
Lavender, Lavandula. .">'.» 
Lawson Cypress, see Chnmaccyparia 

Lebanon Mountains, 67, 68 



:\s-2 



INDEX 



Lecythis, Lecvthidaceae, 276, 280, 
282 

Ledum, 37 

Leguminosae, 108, 185, 215, 218, 228, 

233, 275, 279, 286, 288, 292, 309, 

332, 349, 351 
Lemon, 52 

Loontopodium alpinum, 49 
Lepidium, 57, 144 
Leptospermum, 232, 331, 341 
L. floribundum, 232 
L. scoparium, 341 
Leptopteris, see Todea 
Leschenaultia, 329 
L. formosa, 329 
Lettuce, 1 
Leuceria, 361 
Leucodendron, 310 
L. argenteum, 310 
Leucothoe, 101 
Liana, 160, 161, 175, 185, 206, 207, 

214, 220, 228, 237, 244, 273, 275, 

276, 288, 296, 339, 346 
Liatris, 107 
Libertia, 349, 366 
Libocedrus, 124, 360, 363, 369 
L. decurrens, 124, 359 
L. tetragona, 359 
Licuala, 203, 237, 246 
L. Mulleri, 246 
Lichens, 33, 50, 223, 231, 239, 269, 

297 
Lichen tundra, 33 
Lilac, 49 
Liliaceae, Lilium, Lily, 50, 78, 79, 81, 

143, 240, 241, 316, 325, 330, 366 
L. auratum, 79, Fig. 16 
L. bulbiferum, 50 
L. Humboldtii,143 
L. martagon, 50 
L. parvum, 150 
L. Philippinense, 240 
L. rubescens, 143 
L. Washingtonianum, 143 
Lily of the Valley, 50 
Limber pine, see Pinus flexilis 
Limnanthes, 143 
Linden, see also Tilia, 47, 48 
Lindera, 230 
Linnaea borealis, 37, 39, 41, 90, 128, 

151 
Liquidambar, 10, 11, 91, 96 
L. Styraciflua, 96 
Liriodendron tulipifera, see also 

Tulip-tree, 11, 74 
Listera, 36, 193 

Liverworts, 7, 194, 210, 228, 232, 237, 
238, 239, 284, 292, 346, 347 



Live oak, see also Quercus, 113, 141 

Livingstone Island, Zambesi, 174 

Lizard-tail, see Saururus 

Llanos, 274 

Lobelia, Lobeliaceae, 103, 170, 239, 

252, 258, 318, 361 
Locust, see also Robinia, 47, 96, 101 
Lodge-pole pine, see also Pinus 

Murrayana, 43, 115, 116, 148 
Lodoicea Seychellarum, 199 
Loganiaceae, 274 
Long's Peak, 114 
Lomatia, 363, 365 
Lonicera involucrata, 120 
Loose strife, Ly thrum, 94 
Loranthus, 172, 268 
Lotus, see also Nelumbo, Nymphaea, 

50, 64, 81, 94 
Lupin, Lupinus, 42, 93, 109 
L. Nutkanus, 120, 131, 137, 142, 286, 

361 
Luzon, Philippine Islands, 236, 239 
Lychnis, 48 
Lycium, 307, Fig. 83 
Lycopod, Lycopodineae, see also 

Club-moss, 35, 39, 113, 193, 295, 

334, 347 
Lycopodium, 35, 39, 113, 128, 193, 

216, 230, 232, 240, 295 
L. Carolinianum, 193, 295 
L. cernuum, 113, 295 
L. clavatum, 193, 240, 272 
L. complanatum, 232, 240 
L. Phlegmaria, 216, 230 
L. volubile, 232 
Lygodium, 189, 203, 212, 293 
Lysichiton, 40, 129 

Macadamia, 334 

Macchie, 53, 61, 66, 306 

MacDonald, Lake, 118, 119 

Mackenzie River, 43 

Macrocystis, 39, 128, 136 

M. pyrifera, 128 

Macroglossum Alidae, 213 

Macrozamia, 249, 331 

M. Fraseri, Fig. 91 

Madagascar, 197, 198 

Madeira, 52 

Madras, 186 

Madrono, see also Arbutus, 141, 266 

Magalisberg, Transvaal, 319 

Magnolia, 11, 27, 70, 72, 74, 80, 83, 

100, 101, 240 
M. acuminata, 98 
M. glauca, 90, 98 
M. grandiflora, 98 
M. macrophylla, 98 



INDEX 



383 



Maguey, see Agave 

Mahogany, see also Swietenia, 181, 

301,303 
Maiden-hair, see Adiantum 
Maine, 89. 90 
Maize, 319 
Majorca, 58, 61 

Malaya, Malay Archipelago, 200-243 
Mallee, see Eucalyptus 
Mallow, 286 
Malpighiaceae, 268, 274, 282, 286, 

288, 292, 367 
Malus, see also Crab-apple 
M. coronaria, 93 
Malvaceae, see Mallow 
Man, agent in distribution, 17 
Mandrake, see also Podophyllum 
Mango, 197 

Mangosteen, see also Garcinia, 197 
Mangrove, 112, 159, 160, 163, 164, 

171, 182, 211, 224, 236, 275, 288, 

314, Figs. 26, 68 
Manila, 236 

Manuka, see Leptospermum 
Manzanita, see also Arctostaphylos 

141, 146 
Maple, see also Acer, 11, 26, 39, 47, 

48, 62, 70, 81, 83, 87, 89, 92, 101, 

103, 119, 130, 230 
Marattia, Marattiales, 168, 296 
M. fraxinea, 168 
Mariposa, see Calochortus 
Maquiling, Mount, Philippine Islands, 

236 
Marsilea, 236 
M. crinita, 236 

Marsh marigold, see also Caltha, 36 
Martha's Vineyard, 100 
Massachusetts, 90 
Mascarene Islands, 198 
Matabele Plateau, 171 
Mate, see Ilex Paraguay ensis 
Mattang, Mount, Borneo, 211, 214, 

216 
Matonia, 209, 210, 213 
M. pectinata, 209 
M. sarmentosa, 213 
Matoppos, Rhodesia, 172 
Maui, Hawaii, 268 
Mauritia, 281, 292, 293, 296 
M.flexuosa, PI. XXXIV 
M. sctigera, 296 

Maximiliana regia, 274, 281, 288, 296 
Medan, Sumatra, 21'.) 
Medicago denticulata, 361 
Medinilla, 209, 238 
Mediterranean region, 52 66 
Melaleuca, 203, 2:;.'), 239. 240, 331 



Melastoma, Melastom 121, 

274.2SS, 292 
Melbourne, 22 
Meliaceae, 245 
Menispermum. 76 
Merapi, Mi ., Java, 226 
Mertensia, 42 
M. paniculata, 42 
Mescal, 265 
Mesembrvanthemum, 52, 63, 137, 

307,309,318,320,321 
M. calamaeforme, Fig. S5 
Mesopotamia, 66 
Mesozoic, 70 

Mesquit, see also Pmsopis, 265, 303 
Metrosideros, 252, 341 
M. lucida, 341 
M. polymorpha, 252 
M. robust a, 341 
M. tomentosa, 341 
Mexico, 84, 156, 263-266, 269 
Michelia, 230 
Michigan, 91, 92, 93 
Michigan, Lake, 105 
Milkweed, see also Asclepias, 93, 94, 

108, 320 
Millet, 186 
Mimosa, see Acacia 
Mimoseae, 279 
Mimulus, 115, 120, 143, 148 
Mimusops, 113, 374 
Minnesota, 91 
Mirabilis, 267 
Mississippi Valley, 84 
Mistletoe, see also Loranthus, Phorar 

dendron, Viscum, 268 
Mohria Caffroruin, 319 
Mojave Desert, 126, 144 
Molucca Islands, 235 
Monarda, '.»! 
Moneses, 36 
Mongolia, 37, 74 
Monimiaceae, 365 
Monkshood, 148 
Monkey-flower, see Mimulus 
Monkey-pod, see Pithecolobium 
Monoclea Forsteri, 347 
Monotropa uniflora, 1 19 
Monstera, 27s, 290 
M. deliciosa, 278 
Montana, 86, 117 
Montana de Canelos. An les, 284 
Mont. 'ivy Cypress, Cupressua macro- 

carpa, L37j 313 
Monterey Peninsula, 1">7 
Monterey Pine, Pinus radiata, 137, 

L38 
Montrichardia arborescens, 278, 288 



384 



INDEX 



Moon-seed, see Menispermum 

Moor, Moorland, 47, 51, 83, 90 
Moraceae, see also Fig, 279 
Moraea, 170, 307, 308 
Morning glory, see also Ipomoea, 

•27 'A, 274 
Morocco, 57, 60, 63 
Morus, 106 
M. rubra, 106 
Moss, 7, 31, 32, 194, 230, 231, 269, 

284, 347 
Moss-forest, 209 
Moss-tundra, 31, 32 
Mountain-ash, 39, 129 
Mountain-laurel, see Kalmia 
Mucima, 185 
Muehlenbeckia, 350, 361 
Mulatto tree, see Eucalysta 
Mulberry, see Morus 
Musa, Musaceae, see also Banana, 

162, 208, 220 
M. Malaccensis, 208 
M. violacea, 208 
Myrica Caroliniana, 90 
Myristica, Myristicaceae, 162, 280 
Myrcia, 280 
Mvrsine, 230 
Myrtle, Mvrtaceae, 24, 27, 60, 223, 

228, 230, 239, 274, 280, 286, 314, 

332,341,351,363 
Myrtus, 60, 332, 358, 365, 366 
M. communis, 60 
M. luma, 365, 366 
M. nummularia, 358, 363 

Nantucket, 90, 100 

Narcissus, 45, 53, 64 

Nasturtium, see Tropoeolum 

Natal, 313-316 

Natal plum, see Carissa 

Nebraska, 106, 108 

Needles, California, 126 

Neem, see Azaderachta 

Negro, Rio, 274, 282 

Nelumbo, 94 

Nemophila, 142 

Neotropics, Neotropical regions, 262 

Nepenthes, see also Pitcher-plant, 

199, 206, 208, 213, 216, 220, 

325, Fig. 61 
N. Rajah, 213 
N. Veitchii, 216 
Nephelium, 215 
Ncreocystis, 39, 128, 136 
N. Lutkeana, 136 
NVrine, 308 

Nertera depressa, 332, 359, 363 
Nevada, 121, 123 



New Brunswick, 88, 89, 100 

Newfoundland, 44, 89 

New Guinea, see also Papua, 25, 235, 

321 
New Hampshire, 89 
New Jersey, 88, 96, 100, 101 
New South Wales, 325, 326, 334, 363 
New York, 91 

New World Tropics, see Neotropics 
New Zealand, 14, 321, 333, 335-352, 

354 
Nibong, see Oncosperma 
Nikau palm see also Rhopalostijlis, 

341,344 
Nikko, Japan, 81, 82 
Nile delta, 64 

Nilgiri Hills, India, 179, 187 
Nipa, 182, 183, 201, 211, 219, 224, 226 
N. fruticans, 201 
Nolina, 154, Fig. 48 
North Africa, 60 
North Carolina, 98, 101 
North Queensland, Australia, 243, 

244, 245, 248, 249 
North Temperate Zone, 26, 45, 84 
Northea Seychellarum, 199 
Norway Pine, Pinus resinosa, 92 
Norway Spruce, Picea excelsa, 58 
Nothofagus, 342, 343, 350, 358, 362, 

364, Figs. 94, 101, PL LI 
N. antarctica, 358 
N. betuloides, 358 
N. Cliff ortioides, 343 
N. fusca, 343 
N. Menziesii, 343 
Nothopanax, 339 
Nuphar, 44 
Nutmeg, see also Myristica, 235, 237 

Oahu, Hawaii, 255 
Oak, see also Quercus, 10, 23, 45, 46, 
52, 57, 59, 72, 78, 81, 85, 89, 91, 
95, 103, 106, 223, 266, 268, 270 

Cork oak, 57, 59, 65 

Ilex oak, 52, 58 

Live oak, 113, 141 

Red oak, 85 

Scarlet oak, 96 

Tanbark oak, 140 

White oak, 85, 96, 141 
Oak openings, 92, 105 
Oases, 63 

Oats, see also Arena, 142 
Oberonia, 193 
Ocatilla, see Fouquiera 
Ocean currents, agents in distribu- 
tion, 16 
Oceanic Islands, Chile, 370 



INDEX 



385 



Ochagavia elegans, 370 
Odontoglossum, 386 
Ohio, 96 

Oil-palm, see also Elaeis, 168 

Old World Tropics, see Palaeotropics 

Olea, Olive, 53, 55, 60, 318, Fig. 8 

O. chrysophylla, 318 

O. svlvestris, 60 

Oleander, 59, 81 

Oncidium, 286 

Oncosperma, 202, 211, 219, 228, 237, 
Fig. 57 

O. horrida, 202, 211,228 

Onoclea sensibilis, 83 

Ontario, Canada, 91 

Oodnadatta, Australia, 328 

Ophioglossum, 113, 189, 193, 230 

O. palmatum, 113 

O. pendulum, 189, 230 

O. reticulatum, 193 

Opuntia, 144, 320, 354 

Orchid, Orchidaceae, 35, 42, 48, 50, 
53, 80, 90, 95, 113, 129, 151, 174, 
189, 193, 198, 199, 218, 220, 230, 
238, 277, 295, 301, 307, 308, 325, 
249 

Orchis rotundifolia, 42 

Oreodaphne, 66 

Oreodoxa, 113, 269, 295, 298 

O. oleracea, 295, 298, Fig. 62 

O. regia, 113,295 

Oregon, 123 

Orinoco, River, 274, 283 

Orizaba, Mt., 264, 269 

Ornithogalum, 64, 318 

Orobolus, 367 

Orthocarpus, 367 

Osmunda, Osmundaceae, 83, 101, 
346 

O. cinnamomea, 83, 101 

O. regalis, 101 

Ostrya, 48, 106 

Otira Gorge, New Zealand, 345 

Ourisia, 343, 350 

O. macrocarpa, 343 

Ouvinandra fenestralis, 198 

Oxalis, 108, 308, 309, 355 

O. cernua, 309, 355 

Oxydendron, 98 

Oxytropia, 31 

Pachycereus Pringlei, 270, Fig. 79 
Pacific Coast, P. Slope, United States, 

85,86-114 
Pacific Slope of Andes, 286 
Padang Highlands, Sumatra, 221 
Padina, 101 
Pahang Gap, Malay Peninsula, 206 



Palms, 1, 11, 27, 72, 81, 198, 201, 
206, J<)7, 21 I, 215, 228, 237, 260, 
268, 269, 280, 284, '-"'I. 370 

Palaeotropics, 157, 200 

Palawan, Philippine Island- 2 

Palestine, 66, 68 

Palmetto, see also Sabal, 100, 101, 

103, 110, 303 
Palmiste, see Oreodoxa oh- r area 
Palo-verde, Parkinsonia, 152 
Pandanus, see also Screw-qrine, 1»'»<). 

185, 188, 209, 217, 221, 230, 236, 

243,257, Fig. 62, PI. XV 
P. candelabrum, 160 
P. obeliscus, 198 
P. tectorius, 236 
Pangerango, Mount, Java, 230 
Panicum, 108, 163, 318 
Papilionaceae, 50, 57, 279, 329. 332 
Papua, see also New Guinea, 243, 321, 

351 
Papvrus, see also Cyperus, 162, 169, 

*174 
Para, 275, 276 
Para rubber, see Hevea 
Paramaribo, 290 
Parks, Colorado, 115 
Parnassia, 36, 42, 50, 120 
Pasania densiflora, 132 
Paspalum, 163 
Passion-flower, Passiflora, Passiflora- 

ceae, 100, 273, 275, 283, 370 
Pat ana, Cevlon, 191 
Patagonia, 14, 358, 368 
Pattersonia, 330 
Peach, 197, 316 
Pear, 46 
Peat-bogs, 95 
Peat-moss, see Sphagiiwn 
Pedicularis, 31, 49, 120 
P. Groenlandioa, 31, 120 
Pelagophycus, 136 
Pelargonium, 170, 307 
Pellaea, 172, 319 
P. calomelanoe, 319 
Peltophorum Africanum, 173 
Pentstemon, 45, 120, 121, 143, 149 
Pennisetum, 166, 243 
P. purpureum, L t * * > 
Peony, 76 

Peperomia, 113. 244, 277, 300, 347 
Pepper, Piper, Piperaeeae, 72, v ". 

185, 1«>7.2K> 
P. Mestoni, 244 
Pepper-tree, ~>7, 369 
Pepperidge, Bee also Nysaa, 9 
Perfume, extraction from flown- "> » 
Permian, 3, 4 



3SG 



INDEX 



Perot is, 163 

Persimmon, see also Diospyros, 96 

Persian Gulf, 67 

Petunia, 361, 369 
Phacelia, 142 

Phajus, 232 

Phaseolus, 170 

Philadelphia, climate of, 22, 86 

Philadelphia, 83, 146, 189 

P. Lewisii, 149 

Philippines, 235-240 

Phlox, 93, 103, 109, 121 

Phoenix, see also Date, 170, 174, 181, 

314 
P. reclinata, 170, 314 
P. sylvestris, 181 
Phoradendron, 127, 268 
P. flavescens, Fig. 34 
Phormium, 338, 341, 345 
P. Colensoi, 345 
P. tenax, 338, 341, Fig. 92 
Phragmites, 163, 319 
P. communis, 319 
P. vulgaris, 163 
Phyleria angustifolia, 60, Fig. 8 
Phyllocladus, 334, 339 
P. trichomanioides, 339 
Phytelephas, 284 
Picea, see also Spruce, 32, 38, 43, 46, 

115 
P. alba, 32 
P. Canadensis, 43 
P. Englemanni, 115 
P. excelsa, 46 
P. Sitchensis, 38 
Pickerel-weed, see Pontederia 
Pickeringia, 144 
Pinanga, 201 
Pine, Pinus, 11, 24, 26, 34, 37, 41, 43, 

45, 46, 52, 56, 58, 61, 70, 91, 92, 

101, 102, 109, 110, 123, 223, 241, 

264, 266 
P. albicaulis, 131, 149 
P. Banksiana, 43, 45, 92 
P. Caribaea, 102, 110, Fig. 25 
P. cembra, 38 
P. densiflora, 81 
P. excelsa, 70 
P. flexilis, 115 

P. Halepensis, 58, 60, 61, Fig. 10 
P. insularis, 239, Fig. 67 
P. Lambertiana, 148, Fig. 42 
P. laricio, 56 
P. longifolia, 70, 184 
P. Mercusii, 223 
P. monticola, 130, 149 
P. Murrayana, 125 
P. palustris, 102 



Pinus Parryana, 138 

P. Pinaster, 52, 58 

P. Pinea, 52 

P. ponderosa, 115, 124, 147, 148, 

Figs. 33, 41 
P. radiata, 137, Fig. 37 
P. resinosa, 92 
P. rigida, 90, 101 
P. Sabiniana, 146 
P. Strobus, 91 
P. sylvestris, 46, 52 
P. taeda, 101 
Pine-barrens, 96, 100 
Pipsissewa, see Chimaphila 
Pipul, see Ficus religiosa 
Pistacia, 60 
P. Lentiscus, Fig. 8 
Pitch-pine, see P. taeda 
Pitcher-plant, see also Darlingtonia, 

Nepenthes, Sarracenia, 101, 146, 

213 331 
Pithecol'obium, 206, 237, 275, 279, 295 
P. saman, 295 

Pittosporum, 80, 170, 257, 339 
P. tobira, 80 

Plane, Platanus, 68, 70, 96, 144 
P. occidentalis, 96 
P. orientalis, 68 
P. racemosa, 144 
Plantain, (Plantago,) 57, 191 
Plantain, (Musa,) 197 
Platanthera, 170 
Platycerium, 248. 334 
P. grande, 248 
Platydesma, 258 
Platystemon, 143 
Pleistocene, 4, 6 

P. glaciation, 6, 13 
Pliocene, 3, 11 
Plum, 48, 78, 93 
Pneumatophore, 103, 183 
Poa, 338, 345, 352 
P. Astoni, 352, Fig. 99 
P. caespitosa, 338, 345, Fig. 95 
Podalyria, 311 
Podocarpus, 24, 171, 215, 230, 238, 

239, 249, 303, 317, 363, 365, 366 
P. Chilensis, 365 
P. dacrydioides, 346 
P. elongata, 313 
P. gracilior, 171 
P. Totara, 338 
Podophyllum, 76 
Podostemon, 174 
Pogonia, 45, 366 
P. tetraphylla, 366 
Poinciana regia, 148 
Poison ivy, 83, 93 



l\di:\ 



387 



Polemonium, 42 
Polygala, 170, 311, 318 
Polygonum, Polygonaceae, 33, GG 

Polvgonatum, see Solomon's seal 

Pofvpodium, 230, 290 

Polynesia, 200, 249, 259 

Polytrichum, 31 

Polystichum vestitum, 342, Fig. 94 

Pomegranate. G7 

Pontederia, Pontederiaceae, 94, 278 

Poplar, Populus, 10, 11, 23, 26, 35, 

41, 43, 47, 53, 90, 118, 129, 179, 

26G 
P. balsamifera, 41 
P. Euphratica, 179 
P. trichocarpa, 118, Fig. 28 
Poppy, Papaver, 28, 30, 47, 120 
P. nudicaule, 30, 120 
Port Antonio, Jamaica, 301 
Portugal, 54 

Portuguese West Africa, 165 
Portulaca, 369 

Postelsia palmaeformis, 136, Fig. 36 
Pothos, 220, 244 
P. longipes, 244 
Potomogeton, 94 

Prairies, 85, 92, 106, 109, 110, 130 
Pre-Cambrian, 5 
Pretoria, 319 
Pricklv-pear, see also Opuntia, 57, 

100, 354 
Primrose, Primula, Primulaceae, 30, 

48, 49, 51, 170, 232 
P. auricula, 49 
P. imperialis, 232 
Prince's Pine, see Chimaphila 
Pritchardia, 258 
Prosopis, 156, 257 
Pro tea, Proteaceae, 170, 174, 243, 248, 

307, 310 
P. cynaroides, 310 
P. mellifera, 174 
Prunus, see also Cherry, Plum 
P. avium, 62 

Pseudopanax, 345, 346, 365 
Psilotum, Psilotineae, 113, 216, 334, 

346 
P. flaccidum, 216 
P. triquetrum, 113 
Psilophyta, 8 

Pteridophyte, see also Fern, Horse- 
tail, Lycopod, 8 
Pterocarpus, 172, 206, 224, 237 
Pterocarya, 68 
Pterospermum, 187 
Pueraria, 185 
Puget Sound, 130 
Punica, see Pomegranate 



Pyrenees, 16, 5 1 

Pyrola, Pyrolaceae, 36, 39, 11. 119, 

127 

Quamash, aee ( 'amassia 

Queensland, Australia, 243-249, 325, 
351,354 

Querous, sec also Oak 

(.). agrifolia, 141 

Q. alba, 106 

Q. cerris, 48 

Q. chrysolepis, 140 

Q. cocci nea, 106 

Q. Douglasii, 141 

Q. Garryana, 130 

Q. Ilex, 52, 58, 59, Fig. 7 

Q. Kelloggii, 140, 141 

Q. lobata, 141 

Q. Marylandica, 106 

Q. pedunculata, 46 

Q. robur, 313 

Q. rubra, 106 

Q. sessiliflora, 46 

Q. suber, 57, 59 

Q. velutina, 106 

Quinquinia acutifolia, 346 

Quisqualis Indica, 160 

Rafflesia, 223, 238 

R. Arnoldi, 223 

Raillardia, 258 

Rainier, Mt., 130 

Rajputana, 181 

Rambutan, see Nephelium 

Rangoon, 195 

Ranunculus, see also Buttercup, 49, 

343, 350 
R. Lyallii, 343 
Raphia, 160, 198 
R. ruffia, 198 
R. vinifera, 160 

Rasamala, Altingia exeelsa, 230 
Rata, see Metrosideros 
Rattan, see also Calamus, 185, 203, 

207,215,237,243,246 
Rattlesnake plantain. Bee Goodyera 
Rattle-weed, Bee Astragal 
Ravenala, 198,278,291,292 
R. Madagascariensis, L98 
R. Guianensis, 278, 291, 292, PI. 

XXXIII 
Red Algae, 5 
Red bark, see Cinchona 
Red bud, see also Cere is, 98, 100 
Red bay, see Per sea 
Red oedar, Juniperua Virginiana, 90 
Red maple. Acer rubrum, 101 
Red oak, Quercua rubra, s "> 



bSS 



INDEX 



Red River, 93 

Red spruce, Picea rubra, 89 

Redwood, see also Sequoia, 127, 132, 

133, 138, 139, PI. XI 
Reed, see Phragmites 
Reiche, K., 361 
Reindeer moss, see Cetraria 
Reseda, 64 
Restionaceae, 310 
Rhamnus, 48, 146 
Rhapidophora Australasica, 244 
Rhizophora, see also Mangrove, 112, 

134, 164, 182, 288 
R. mangle, 112, 134,288 
R. mucronata, 164, 182 
Rhodesia, 163, 171, 172, 320 
Rhododendron, 1, 28, 30, 37, 38, 68, 

70, 76, 209, 216, 223, 230, 232 
R. arboreum, 191 
R. Californicum, 130, 140 
R. Javanicum, 230, 232 
R. Lapponicum, 30 
R. retusum, 232 
R. salicifolium, 214 
Rhodophyceae, see Red Algae 
Rhopalostylis sapida, see also Nikau, 

341, 344, PI. XLVIII 
Rhus, see also Sumac, 49, 83, 146, 

170, 310 
R. cotinus, 49 
R. diversiloba, 141 
R. toxicodendron, 83 
Rhyniaceae, 8 
Ribes, 41, 146 
Rice, 53, 57, 197, 224 

Wild rice, see Zizania 
Rio Colorado, Argentina, 357 
Rio Negro, 274, 282 
Robinia, see also Locust 
R. pseudacacia, 96 
Robinson, B. L., 300 
Rochea, 311 
Rock-rose, see Cistus 
Rocky Mountains, 15, 31, 85, 114, 

116 
Romneya, 143 
Romulea, 308 

Rose, Rosa, 41, 42, 45, 48, 76, 78, 90, 
98, 129 
Banksia R., 78 
Cherokee R., 78 
Fortune's Yellow R., 78 
R. Arkansana, 108, 109 
R. Chinensis, 76 
R. Nutkana, 41 
Rosaceae, 266, 269 
Roupala, 363 
Royal palm, see Oreodoxa 



Rubber, 161, 189, 197, 198, 201, 222, 

224 
Rubiaceae, 172, 218, 258, 274, 279, 

284, 286, 292 
Rubus, see also Bramble, Raspberry, 

39, 45, 118, 129, 170, 222, 232 
R. Nutkanus, 120, 140, 150 
R. spectabilis, 129 
R. ulmifolius, 366 
Rumex, 116 
R. maritima, 116 
Russia, 29 
Rutaceae, 258, 327 

Sabal, 101, 103, 111,269 

S. Adansonii, 103 

S. palmetto, 101, 111, PI. X 

Saccharum spontaneum, 163, 222 

Sachalien, 83 

Sacramento Vallev, 134, 145 

Sage-brush, 66, 122, 124 

Sagittaria, 94 

Sago-palm, 211, 235 

Sahara, 25, 65, 67, Figs. 13, 14 

St. Lawrence, 91 

Sal, see Shorea 

Salak, Mount, Java, 225, 226 

Salal, see Gaultheria 

Salicornia, 116 

S. herbacea, 116 

Salix, see also Willow, 279, 318 

S. Capensis, 318 

S. Humboldtii, 279 

Salmon-berry, see Rubus spectabilis 

Sal sola, 57 

Salt-bush, see also Atriplex, Salsola, 

57, 66, 68, 328 
Salvia, 48 
Sal ween River, 195 
Samoa, 249, 250, 251 
San Ambrosio Island, 370 
San Bernardino Mountains, 134 
Sandalwood, see Santalum 
Sand verbena, see Abronia 
San Francisco, 

Climate, 88, 126 
Sanguinaria, 45 
Sanicula, 138 

San Jacinto Mountains, 134, 152 
San Joaquin Valley, 134, 145 
Sanseviera cylindrica, 165 
Santalum, Santalaceae, 172, 257, 328 
Santubong, Mount, Borneo, 211, 214 
Sarawak, Borneo, 210, 211 
Sarawak River, 211 
Sarcobatus, 122 
Sardinia, 59 
Sargassum, 101 



INDEX 



389 



Sarracenia, 96, 101 

Sassafras, 11, 72, 76, 96 

Satyrium, 170, 193, 308 

Savanna, 173, 290, 292, 293, 296, 

Fig. 52 
Saw-palmetto, Serenoa serrulata, 102, 

110,112 
Saxifrage, Saxifraga, 28, 30, 31, 50, 

151,339,365 
S.peltata, 151, Fig. 45 
Scaevola, 159 
Scandinavia, 29, 37 
Scarlet flax, Linum grandiflorum, 65 
Scarlet maple, see Red maple 
Schellia splendens, 276 
Schinus molle, see Pepper-tree 
Schizaea, Schizaeaceae, 88, 101, 216, 

296, 319 
S. pennula, 296 
S. pusilla, 88, 101 
Schizanthus, 361, 369 
Schmidtea, 163 
Schneeberg, Austria, 49 
Sciadopitys, 76 
Scilla, 361 
Scindapsus, 220 
Scirpus, 44, 94, 145 
Scitamineae, 80, 162, 276, 277, 367 
Sclerolobium, 281 
Scotch pine, see Pinus sylvestris 
Scotland, 51 
Screw-pine, see also Pandanus, 16, 

182, 214, 217, 228, 234, 236, 246, 

249, 253, 325, Fig. 62 
Scrophulariaceae, 367 
Sea-palm, see Postelsia 
Sea-rocket, see Cakile 
Sealingwax palm, see Cyrtostachys 
Seed-plants, 8, 9, 10 
Sego-lily, see Calochortus, 123 
Selaginella, 113, 172, 230, 276, 319 
S. Dregii, 172, 319 
Senecio, 109, 120, 314, 361 
Senegal, 165 

Sensitive fern, see Onoclea 
Sequoia, see also Redwood 
S. gigantea, 147 
S. sempervirens, 132 
Service berry, see Amelanchier 
Seymour Island, 13 
Seychelles Islands, 199 
Shasta, Mount, 85, 186 
Shepherdia, 41, 43 
Shooting star, see also Dodecatheon, 

107 
Shorea robusta, 184 
Siam, 195, 196 
Siberia, 28, 29, 36, 37 



Sicily, 52 

Sideroxylon, 113, 249 

Sierra Nevada, 15, 31, 145 

Sikkim, India, 72 

Silene, 48, 50 

Silk-cotton, see Bombax, Ceiba 

Silk-oak, see Grevillea 

Silurian, 5 

Silver fir, see Abies pectinata 

Silver linden, see Tilia argentea 

Silver maple, Acer saccharinum, 106 

Singapore, 204, 206 

Sisal hemp, Agave rigida, var. Sisilan, 

265 
Sisvrinchium, 108, 143, 361 
S. bellum, 143 
Sitka, 86, 128 

Sitka spruce, see Picea Sitchensis 
Skagway, 40 
Skimmia, 74 

Skunk-cabbage, see Lysichiton, 
Smoke-bush, see Rhus cotinus 
Snowberry, Symphoricarpus, 120 
Snow-plant, Sarcodes sanguinea, 148 
Solanum, 161, 275 
Soldanella, 49 

Solidago, see also Goldenrod, 115 
Solomon's Seal, Polygonatum, 50 
Sonchus, 57 
Sonneratia, 182 
Sonoran Desert, 267 
Sophora tetraptera, 349, 366, 369 
Sorrel tree, see Oxydendron 
South Africa, 13, 14, 306, 351 
South America, 13, 14, 269, 271-300, 

349 
South Australia, 328, 329 
South Carolina, 101, 102 
South Germany, 47 
South Temperate Zone, 306 
Southern Alps, New Zealand, 336 
Spain, 52, 53, 54-59 
Spanish Cedar, see Cedrela 
Spanish Moss, see Tillandsia 
Sparganium, 44 
Sparmannia, 170 
Spartium junceum, 59 
Spathodea campanulata, 162 
Spathiphyllum cannaefolium, 295 
Spathoglottis, 204, 220 
Spermatophyte, see Seed-plant 
Sphagnum, 31, 209, 238, 290, 347 
Spice Islands, see Molucca 
Spiraea, 39, 41, 72, 78, 90, 93, 98, 120 
Spitzbergen, 27, 28, 29 
Spraguea, 148 
Spring beauty, see also Claytonia, 

87 



390 



INDEX 



Spruce, see also Picea, 32, 38, 40. 42. 
43. 45. 46. 58, 67, 70. 74. 92, 128, 

130. 139 
Spruce, R., 271, 276, 281, 283 

Stachys. 169 

Staghorn fern, see Platycerium 

Stanley Park. Vancouver. 130 

Stapelia. 320 

Star of Bethlehem, see also Ornitho- 

galum, 64 
Stenandrium, 361 
Stenocarpus. 24S. 334 
Sterculia. 165. 184 
S. tomentosa, 165 
Steppes. Mongolia. 76 

-outhwest United States. S6. 106 
Stipa, 63, 10S. 142, 357 
S. tenacissima, 63 

Stone-crop, see also Crass ula. Cotyle- 
don, 50, 120 
Stone-pine, see Pinus Pinea 
Stonewort. see Characeae 
Stramonium, 354 
Strand floras. 
Borneo, 217 
New Jersey. 100 
Strangling figs, 161 
Strawberrv, see also Fragaria, 138, 

369 
Strawberry-tree, see Arbutus 
Strelitzia Augusta, 314 
Strobilanthus, 193 
Strongvlodon, 237 
Strychnos, 172. 173, 314 
S. pungens. 319 
Suarro. see Cereus giganteus 
Sub-alpine floras, 50. 122. Fig. 31 
Sub-alpine scrub. New Zealand. 343. 

347 
Sub-Antarctic flora, 349, 365 
Sub-Arctic Zone, 34 
Sudd, 169 
Sueda, 123 

Sugar cane, 163, 222, 253 
Sugar maple, Acer saccharum, 87, 

92 
Sugar palm, see Arenga 
Sugar pine, see also Pinus Lamberti- 

ana, 148, 150 
Sumac, see also Rhus, 83, 90, 98, 118 
Sundarbuns, India, 182 
Sundew, see also Drosera, 93, 101, 

193, 296, 309, 330, 367 
Sunflower, 93. 106 

Surinam, 285. 287, 288, 289, 292, 294 
Sutherlandia frutescens. 309 
Suttonia divaricata, 347. Fig. 97 
Sweet bay, see Magnolia glauca 



Sweet briar. 20, 354 
Sweet fern, see Comptonia 
Sweet gum, see Liquidambar 
Swietenia. 303 
Switzerland. 49. 50 
Sycamore, see Platanus 
Sycamore fig, see Ficus sycamora 
Sycamore maple, see Acer pseudo- 
platan us 
Syngonium. 290 
Syringa. see Philadelphia 
Syzygium, 175. 314 
S. cordatum, 314 

Table Mountain, South Africa, 210, 

311 
Tahiti. 249, 253 
Taiping Hills, Malav Peninsula, 203, 

207 
Talipot palm see also Corypha, 191, 

192, PI. XVII 
Tamarack, see Larix Americana, 

Pinus Murrayana 
Tamarind, Tamarindus, 170, 228 
Tamarisk, Tamarix, 63 
Tanbark oak, see Pasania 
Tapang, see Abauria 
Tarairi, see Beilschrniedia 
Tasmania. 14. 334. 349. 351, 354, 359 
Taxodium, 11. 102. 103 
T. distichum. 102. 103, Fig. 21 
Taxus, Taxaceae, 46, 119, 140, 238, 

241, 334, 346 
T. baccata, 46 
T. brevifolia, 119, 140 
Tea, see Thea 
Teak, Tectona, 186, 233 
T. grandis, 186 
Tecoma, 100, 282, 314 
T. Capensis. 314 

Tehachapi Mountains, California, 134 
Tell. Algeria, 61 
Telopea speciosissima, 327 
Tennessee, 96 
Terai, India, 183 
Terebinthaceae, 269 
Terminalia, 113. 172. 173, 181, 184, 

206. 234. 236 
T. Catappa, 181, 217, Fig. 72 
T. sericea. 173 
Tertiary, 6 
T. climate, 12 
T. flora, 27. 68 
Texas, 102. 103, 106 
Thalictrum, 168 
Thamnoseris lacerata, 370 
Thea, Theaceae, 72 
Thecophilaea, 361 



INDEX 



391 



Theobroma cacao, 296 

Thimbleberry, see Rubus Nutkanus 

Thistle, 48 

Thrinax, 303 

Thuya, 89, 92, 119 

T. occidentalis, 89, 92 

T. plicata, 119 

Tibet, 70 

Tideland spruce, see Picea Sitchensis 

Tierra caliente, Mexico, 265, 266 

Tierra del Fuego, see also Fuegia, 14 

Tierra templada, Mexico, 266 

Tiger orchid, Grammatophvllum, 216 

Tilia, Tiliaceae, 48, 92, 96, 106, 365 

T. argentea, 48 

T. Americana, 92, 96, 101 

Tillandsia, 103, 111, 269, 290, 300, 

PL X 
Timor, Island, 234 
Tjibodas, Java, 230 
Tmesipteris, 334, 346 
Tobacco, 186, 219 
Todea, 314, 339, 346 
T. barbara, 314 
T. superba, 339, 346, Fig. 93 
Torre va, 76, 113, 140 
T. Calif ornica, 113, 140 
T. taxifolia, 113 

Totara, see Podocarpus 

Trailing arbutus, see Epigaea 

Transvaal, 163, 316, 317, 320 

Traveller's Tree, see Ravenala 

Tree-fern, 72, 73, 185, 206, 222, 228, 
242, 259, 270, 296, 340, Fig. 60, 
Pis. IV, XXI, XXVII 

Trema, 230 

Treub, M.,233,234 

Trichomanes, see also Hymenophyl- 
luceae, 346 

T. reniforme, 346 

Trillium, 45. 72 

Trinidad, 283, 286, 294, 295, 296, 299 

Tripoli, 63 

Tristanea, 332 

Tritonia, 316 

Trollius, 49, 50 

Tropical Africa, 157-175 

Tropical East Africa, 163 

Tropoeolum, 361, 365, 369 

T. speciosum, 365 

Trumpet creeper, see Tecoma 

Tsuga, 38, 39, 83, 128 

T. heterophvlla, 39 

T. Mertensiana, 128 

Tucuchi, Mt., Trinidad, 296, 298 

Tule, see Stir pus 

Tulip-tree, see also Liriodendron, 11, 
53, 74, 96 



Tumboa, see Welwitschia 

Tundra, 27, 31, 32, 43 

Turkestan, 37 

Tussock grass, see also Bunch grass, 

336, 343, 345, 358 
Tway-blade, see Listera 
Twin-berry, see Lonicera involucrata 
Twin-flower, see Linnaea 
Tvpha, 44 
Tyrol, 50 

LTex, 47 

Ulmus, see also Elm, 91, 92 

U. Americana, 91, 92, Fig. 18 

Ulva, 91 

Umbelliferae, 38, 48, 50, 109, 266 

Upas, see Antiaria 

Uruguay, 282 

Usnea, 194 

Utah, 123 

Utricularia, 174, 193, 290, 296, 298 

U. montana, 297 

Vaccinium, 113, 230, 232, 240 

(see also Cranberry, Huckleberry) 
Vahea, 198 
Valdivia, Chile, 366 
Valeriana, 286 
Vallisneria, 94 
Valparaiso, 361 
Vanda, 196, 215 
V. coerulea, 196 
V. teres, 215 
V. tricolor, 215 
Vanilla, 199, 238, 253 
Vegetable ivory, see also Phytelephas, 

284 
Venezuela, 283 
Venus's fly-trap, see Dionaea 
Veratrum, 49, T20, 149, 150 
V. viride, 120 

V. Californicum, 149, 150, Fig. 43 
Verbena, Verbenaceae, 108, 292, 300, 

358, 369 
Vermont, 89 
Vernonia, 168, 230, 316 
V. amvgdalina, 168 
Veronica, 169, 345, 349, 350 
Vetch, 42, 50 

Viburnum, 43, 56, 93, 98, 120, 187, 230 
V. tinus, 56 

Victoria, Australia, 327, 328, 332, 334 
Victoria Falls, South Africa, 174, 175, 

Fig. 53 
Vine, see also Grape, Vitis, 57 
Viola, Violet, 72, 87, 93, 106, 168, 191 
V. pedata, 106 
Virginia, 101 



392 



INDEX 



Virginia creeper, see also Ampelopsis, 

70 
Vitis, 83, 185, 234, 244 
V. labrusca, 83 
V. trifolia, 234 
Vittaria, 113,230,290 
Vosges, Mts., 46 

Wallace, A. W., 205, 234 

Wallace's line, 235, 240 

Walnut, see also Juglans, 53, 85, 92, 

144, 266 
Waratah, see Telopea 
Warczewiczia coccinea, 296 
Washington, D. C, 126 
Washington, Mt., 84 
Washington, State of, 85, 123 
Washingtonia, 152, 153, 363 
W. filifera, 153, Fig. 47 
Water, agent in distribution, 16 
Watermelon, see Citrullus 
Watsonia, 308, 354 
Wattle, see Acacia 
Waxberry, see Myrica 
Weber's line, 235 
Weeds, 20, 21, 354, 357 
Weigela, 83 
Weinmannia, 198, 346, 363, 365, 

366 
W. sylvicola, 339 
W. trichosperma, 365 
Wellington, New Zealand, 22, 341 
Welwitschia mirabilis, 166, 167, PI. 

XIII 
West Australia, 329-333, 351 

Wild flowers, 331 
Western Europe, 46 
Western Ghats, India, 186 
West Indies, 101, 263 
Westland, New Zealand, 336, 346, 

347, 350 
Wettinia, 284 
White cedar, see Thuya, Chamaecy- 

paris 
White Mountains, 31 
White oak, see Quercus alba, Q. lobata 



White pine, see Pinus Strobus, P. 

monticola 
Whitlow grass, see Draba 
Whitney, Mt., 135 
Willis, Bailey, 370 
Willow, see also Salix, 26, 32, 35, 

41, 45, 47, 108, 279, 318 
Willow-herb, see Epilobium 
Wine palm, see also Caryota, Raphia, 

160, 163, 168, 202 
Wintergreen, see Gaultheria 
Wisconsin, 85, 91, 93 
Wistaria, 81 
Witch hazel, see also Hamamelis, 

76, 98 
Wonder-boom, see Ficus cordata 
Wormia, 199, 217 
W. ferruginea, 199 
Wormwood, see Artemisia 
Wyethia, 149 
Wyoming, 116 

Xanthium, 354 
Xanthorrhoea, 331, 333 
X. Preissii, 333, PI. XLIV 
Xerophytes, 264, 265, 266, 300 
Xyridaceae, 290 

Yam, see Dioscorea 

Yangtse-Kiang River, 74, 79, PI. V 

Yellowstone Park, 116 

Yosemite Valley, 146, 147 

York Peninsula, Australia, 243, 246, 

325 
Yucca, 106, 108, 154, 156, 265, Fig. 48 
Yukon Territory, 40 

Zamia, 9, 109 
Z. Floridana, 109 
Zambesi River, 174 
Zingiber, Zingiberaceae, see also Gin- 
ger, 162, 208, 278 
Zizania aquatica, 94 
Zizyphus, 171, 179 
Zones of vegetation, Mt. Orizaba, 269 
Zygadenus, 143