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During the last decade many have been interested in the study of the flora of Nepal. There have been those who have carried their investigations over years and others who have visited only once, but all have brought valuable information about the distribution of plants in the area. In recent years, Nepal has proved to be rich in new taxa and particularly in the new species of Meconopsis, of Primula and of Pedicularis. Based on the published data, some deductions can be made about the phytogeography of Nepal. Information is gradually accumulating and becoming available as to the range of extension of the widely accepted East Himalayan elements and the West Himalyan elements. It is here in Nepal that the differing floras of the Eastern and Western Himalayas merge. The outstanding result is an expression of the eastern-ness of the vegetation of East Nepal, while in West Nepal the West Himalayan elements abound; thus botanically Nepal is of particular interest. Because of Nepal's importance as an area of “transition” or as we may also call it as an area of “merging”, the geographical subdivisions of Nepal are discussed in the paper. Further, the data at hand is now much more than what was available to Hooker and Chatterjee. The author, in complete agreement with Stearn, proposes that lang: 83°E. may be taken as the boundary between the botanical provinces of Eastern Himalaya and Western Himalaya. It is also pointed out that in the study of the vegetation of such areas where differing floras meet, plotting of geographical positions is a necessity.

The broad geographical range of thermophilous calcareous grass lands in the British Isles affords an excellent subject for research in both phytogeography and phytosociology. The grasslands of the chalk downlands of southern England are quite well-known ecolo gically (Tansley 1939), but the lack of comparative data from the grasslands of the older limestones prevents a detailed phytogeo graphical comparison of component communities of the Class Festuco-Brometea in western Europe. Over a period of four years the regions shown in Figure i were visited and sampled and the results are presented here and in two subsequent papers. Over 500 grassland Aufnahmen were collected and from these, Associations erected, characterised and classified accordingly to the Z?rich-Montpellier School of phytosociology and the system of vegetation classification for central and north-west Europe advocated by Lohmeyer et al. (1962). These Associations have been related to one of the predominant measurable factors which influences plant geography, namely that of climate. For this purpose, modified climate-type diagrams of Walter & Lieth (1967) have been used to illustrate the main climatic trends which are reflected by the floristic composition and structure of the limestone grassland communities.

The high-altitude bogs of Lesotho or "Mokhoabo" are situated in the riverheads of the Orange River system in the eastern escarpment of Southern Africa (Fig. 1). The mountain ranges of Lesotho, the Maluti Mts and the Drakensberg range (highest mountain Thabana Ntlenyana 3484 m) are covered by up to 1500 m thick, early Jurassic, amygdaloidal basalts, in which the tribu taries of the Orange River have cut deep valleys.

Eleven species of the genera Omphalodiscus and Umbilicaria in the lichen family Umbilicariaceae are reported from a 13 400-km2 area in the mountains and foothills of southwestern Alberta. Previous reports of Umbilicaria arctica and U. cylindrica are, or are felt to be, in error. Umbilicaria cinereorufescens is reported as new to Alberta. The distribution and habitats occupied by each of the taxa are described and a key to all species is provided. All taxa obligately occur on rock and in most cases are only on silicate rocks. Ten of the species are Circumpolar, Arctic–Boreal Alpine–Montane, and one is American, Cordilleran.

A sample of the flora of the Cape Peninsula is analysed phytogeographically. The flora is divisible into that of the mountains and that of the Cape Flats. In distribution of the species the mountain flora shows signs of great age. In part it is related to a climate moister than that existing. The Flats flora is more modern.

Our knowledge of the existence of Ice Ages in the Northern Hemisphere is not very old. It dates from about the middle of the nineteenth century. Scientists in various parts of Europe found that the extensive masses of unsorted loose deposits, and the striated and polished rocks could not be explained in any other way than by assuming that a large ice sheet had existed which overrode the country, polishing the rocks and depositing moraine gravel. The signs of glaciation are so abundantly present in almost all parts of Scandinavia that it very soon led to the supposition that the ice mass had covered the whole country and destroyed all plant and animal life. This was the 'tabula rasa' theory. As a consequence of the theory the present flora and fauna of Scandinavia were held to have immigrated after the Ice Age from the south and east. Further indication of this was found in I870 by Nathorst who succeeded in discovering remnants of an arctic flora in southern Sweden in layers deposited just after the ice had retreated. Later many scientists found similar remnants in various places in southern Sweden, Denmark and southern and western Norway. It is remarkable that the frequency of these arctic floras in southern Scandinavia seems to decline towards the north. The remnants of arctic plants are much more scarce in middle Sweden and in the Oslo region in Norway than in southern Sweden and in Denmark. One of the consequences of the 'tabula rasa' theory must be that since the Scandinavian flora is recruited from the south and east, all relationships of that flora must be to the south and east, and hence the Scandinavian flora must be a province of the middle or eastern European. This, however, is not the fact, as far as the Scandinavian arctic and alpine flora is concerned. A strong relationship exists with areas west of the Atlantic, with Greenland and Labrador. Even Blytt, who otherwise accepted the 'tabula rasa' theory, felt uncomfortable about this fact; and after him Sernander (I896), Wille (see e.g. Wille, I915) and Andreas M. Hansen, in the last decade of the nineteenth and the first of the twentieth centuries, advocated the view that the whole Scandinavian flora was not destroyed by the ice during the last Ice Age. Refuges must have existed along the Scandinavian coast where an arctic-alpine flora might have persisted during the Ice Age. The existence of unglaciated areas during the last Ice Age was first confirmed geologically by Vogt (19I3), who on geomorphological ground found that the outer part of the

The purpose of phytogeography is of the simplest. This branch of botany studies dispersal not only in order to learn how plants migrate, but ultimately to ascertain how they evolve while migrating. The why of this double purpose is self-evident, considering that there is no possibility of following plants in their dispersal without coming sooner or later to a region of the earth, where old affinities yield place to new. If phylogeny is not necessarily an integral part of phytogeography, still phylogeny and phytogeography work together so closely that their aims and doings cannot be dissociated.

Our knowledge of the vegetation of the Himalaya is derived mainly from the numerous botanical explorations during the past one hundred and fifty years. The observations of members of some of the mountaineering expeditions have also added materially to our knowledge, not only of the prevailing vegetation but also other aspects like climate, topography, soils, glaciers, etc., with which the plant life is closely correlated. In spite of these many adventurous incursions into the inner ranges, there are still numerous gaps in our knowledge and many remote valleys are, as yet, botanically not very well known. It is proposed to give in this chapter a broad survey of the vegetational types found in the various sectors of this vast mountain system and also attempt a discussion of the phytogeographical affinities of its flora.

Unlike the Western Ghats, the Eastern Ghats are not by any means a range of mountains or escarpment, but represent the much broken and weathered relicts of the Peninsular Plateau, marked by a series of isolated ‘hills’. The Eastern Ghats mark the eastern borders of the Peninsular Plateau and thus extend from the extreme northeast to the south of the Chota-Nagpur Plateau, to the extreme southwest corner of the Peninsula. The eastern edge of the Nilgiri, Anamalai, and Palni Hills are also parts of the Eastern Ghats. The geology and general climatic conditions of this region have been outlined in foregoing chapters. An attempt is made here to present a broad picture of the characteristic vegetation and phytogeographical peculiarities of the Eastern Ghats.

Assam and Burma are parts of the Eastern Borderlands (see Chapters II & XX), a region largely of Tertiary mountains, characterized by highly humid tropical climate and remarkable for the wealth and diversity of vegetation and flora. Indeed over half the total number of Phanerogams, described so far from India, occur in Assam. Biogeographically, Assam and north Burma represent a highly transitional region, where large-scale commingling of the Asiatic and Indian Peninsular Floras has occurred.

The most characteristic feature of present day Australian climatology is the arid centre surrounded by belts of progressively wetter country. The arid zone, bioclimatically determined, is bounded approximately by the 10 inch annual rainfall isohyet in the south, the 25 inch isohyet in the north, the 15 inch isohyet in New South Wales and the 20 inch isohyet in Queensland; it occupies about four-fifths of the Continent.

As delimited by Polunin (1951), the Arctic is situated on the Northern hemisphere North of (1) a line 50 miles North of the coniferous forest line, (2) the Northern limit of microphanerophytic growth, or (3) the Nordenskjold line, according to the formula V = 9-0,1K. According to this delimination the whole of Greenland belongs to the arctic region. Within the Arctic a subdivision in low- and high-arctic regions is usually recognized. Larsen (1960) marks this transition on the East coast of Greenland near Cape Dalton. Low-arctic East Greenland thus stretches from 60° to 69°30' N. lat. The Angmagssalik area in Southeast Greenland ranges from circa 65° to 67°20' N. lat. Between the Sermilik and the Kangerdlugssuatsiak fjords to the West and East, Denmark Strait to the South and the extensive nunatak area Schweitzerland, merging into the central Greenland ice-cap to the North, the Angmagssalik area in stricter sense (35°45' – 38° W. long., 65°30'-66°20' N. lat.) is the largest ice-free region of low-arctic East Greenland and must therefore, and for its isolated and central situation, be regarded as highly representative.

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The pteridophytes of Thailand have recently been studied intensively in the course of the Flora of Thailand project. I have participated in this project and have enumerated some 620 species of pteridophytes from this country. Concerning the phytogeography of Thailand, I have already discussed the species known from the northern part of this country, with special reference to the pteridophytes (Iwatsuki, 1972). It was concluded in that paper that northern Thailand belongs to the extreme southernmost part of the Sino-Himalayan region; the pteridophytes of peninsular Thailand, on the contrary, belong to the Malaysian phytogeographical element. At the beginning of this century, Ridley in 1913 and in several other papers published on the phytogeography of northern Malaya and lower Siam, chiefly based upon his own field observations; his data, however, are insufficient to compare with those available at present. In his comprehensive book on Malayan ferns, Holttum (1954) noted the distribution of Malayan ferns in lower Siam.

In order that we may clearly understand all of the steps that have led up to the interesting development of the flood plain of the Coeur d'Alene Basin it is necessary to recall the geology of the region, for the indications are convincing that the Coeur d'Alene Basin of to-day differs markedly from that of premiocene times. According to Ransome and Calkins (i908), Coeur d'Alene Lake, along with Hayden Lake and Lake Pend d'Oreille of northern Idaho, and Kootenai Lake of southern British Columbia, lies in what is known as the Purcell Trench, the whole system of lakes constituting a remarkable physiographic feature of the region (Fig. i). No main stream now runs the length of this trough, but instead we find it filled with a heavy deposit of silt, laid down by what was doubtless in pre-miocene times a portion of that fork of the Columbia River of which Kootenai Lake is now a part. The miocene lava flow apparently crept up the valleys of this ancient river, partly filling many of them by pushing long tongues of lava up their principal courses and their tributaries. The Coeur d'Alene Lake of our day lies in the path of the river in question, and affords a fairly convincing illustration of the course of physiographic changes. For on either side of the lake may now be seen the terraced remains of miocene basalt occupying the slopes of the ancient river valley. The lava-filled valleys, through processes of erosion, were subsequently reclaimed by the streams which must have worn ever widening and deeper channels through the basalt. From all the evidence at hand it seems probable that the retreating glaciers of the ice age left behind a deep deposit of pleistocene gravel which doubtless made a permanent stream barrier and served to break the continuity of the river in that part of the Purcell Trench now occupied by Hayden Lake, The Rathdrum Prairie, and the country between Coeur d'Alene Lake and Lake Pend d'Oreille. This gravel barrier, from 2,135 to 2,293 feet above sea level, effectively dammed the course of this fork of the Columbia River and caused the pentup waters to back far up the valleys tributary to what is now Coeur d'Alene Lake (Fig. 2). This resulted in the eastern arm of the lake extending up the valley of the present Coeur d'Alene River; while the southern arm terminated at a point now marked by the eastern limits of the village of Far

The vast grass-covered region of central United States has long been known as the prairies or prairie region. People from the eastern United States or from the Old World have the general idea that this region is a vast uniform steppe similar to southern Russia. This is far from true, for the flora of central Illinois is very different from that of eastern Colorado, as is that of the Saskatchewan plains from that of northern Texas. The reasons for this dissimilarity are manifold. The principal ones are the annual precipitation of central Illinois is about 37 inches and that of eastern Colorado is below 15; and the growing (frost-free) season of Saskatchewan is less than three months and that of the Staked Plains of Texas nearly seven months long. The floras could not be the same. It is unfortunate that this vast grass land did not receive a 'concise and, at the samie time, adequate description in print 50 to 75 years ago, when most of it still had its original vegetation. Now about 75 per cent. or more of the prairies have been turned into fertile fields. It is true that a large part of the Great Plains is still untouched by cultivation; but its original flora has been changed a good deal by over-grazing and the introduction of numerous weeds from other regions. It is now almost impossible to render a true account of the original vegetation, or to produce a reliable phytogeographic map of the region. Until lately, the only fairly reliable published maps of this kind are those of Dr. Merriam in connection with his articles on life zones and crop zones; but these have some serious defects, due to the facts that the author is a zo6logist and that the distribution of animals does not coincide with that of plants, more than due stress being laid on temperature. The most reliable map now published is the Atlas of Natural Vegetation, by H. L. Schanz and Raphael Zon, published in 1924 by the United States Department of Agriculture. While the outlines of the 57

In a quantitative ecological study of the vegetation of Cerro Potosi above 3,500 m, four community types were recognized. 1) The structurally homogeneous alpine meadow is dominated by shade- intolerant, prostrate dicotyledons. Three dominant species comprised 25.7% of the total frequency and 49.3% of total cover. Predominant life-forms are hemicryptophytes and chamaephytes. Typical alpine spe- cies tend to be positively associated among themselves and negatively associated with subalpine species which have invaded the alpine meadow. 2) Subalpine meadows on north slopes are dominated by erect forbs and cespitose grasses. They are interspersed mostly within the P. hartwegii forest. 3) On east, south, and west slopes a dense, krummholz-like P. culminicola scrub extends from about 3,450 m to the periphery of the summit. 4) Immediately below the scrub is a forest dominated by P. hartwegii. On the northeast slope this species extends to the summit. Principal understory species in both the scrub and the forest are forbs and cespitose grasses, very few of which are common to the alpine meadow. Distribution of the summit communities corresponds closely to topographic features. High wind velocities and limited water availability apparently are critical factors in preventing woody species from attaining dominance on the alpine summit. The four communities are climax vegetation types. The summit flora includes 81 vascular species in 65 genera and 30 families. Species endemic to the Sierra Madre Oriental comprise 42 % of the flora; 13 species are known only from Cerro Potosi; 16 species range northward and are generally centered in the southern Rocky Mountains, 15 are distributed principally to the south; Cerro Potosi is the northern limit of two Andean species; four species have semicosmo- politan, arctic-alpine ranges. The flora is probably of Pleistocene age and mostly derived from neighboring populations of lower elevations. The numerous endemics may be the result of catastrophic selection or other factors which have facilitated rapid evolution in isolated, small populations. The unique alpine meadow and Pinus culminicola scrub communities may have been more widely distributed during cooler or more arid periods of the Pleistocene.

MERRILL, RUTH E. 1923. Plants used in basketry by the California Indian. Univ. Calif. Publ. Am. Archaeol. and Ethnol. 20: 213-242. MUNZ, P. A. 1959. A California Flora. Univ. of Calif. Press, Berkeley. MURPHEY, EDITH. 1959. Indian Uses of Native Plants. Desert Printers, Inc., Palm Desert, Calif. ROMERO, J. B. 1954. The Botanical Lore of the California Indians. Vantage Press, New York. SCHENCK, SXRA M. & E. W. GIFFORD. 1952. Karok ethnobotany. Anthropol. Rec. 13: 377-392.

The Australian phytogeographic region is defined as including the Australian mainland and Tasmania. This region may be subdivided into the Tropical Zone in the north and east, the Temperate Zone in the south and east, and the Eremaean Zone in the arid centre. Delineation of these zones is closely linked with present day climates but their floristic constituents also reflect selection resulting from past climatic and geographic conditions. The following areas are of special phytogeographic interest: South-West Province of Western Australia, Tasmania, Sorth-East Queensland, and the MacPherson–Macleay Overlap where the Tropical and Temperate Zones coincide. Three interzone areas have been defined where special circumstances prevent the drawing of zonal boundaries. In Parts A and B floristic analyses covering the distribution of Australian phanerogamic genera are provided for the Australian Region and for the special areas listed above. The analyses deal with family representation, endemism, and the estimated number of species present. The flora of the South-West Province reveals the highest proportion of endemism though there is a close relationship with the flora of the eastern part of the Temperate Zone. The existing west-east affinities and discontinuities are discussed in relation to climatic changes. The Province is not regarded as the "cradle" of the autochthonous elements of the Australian flora though it is apparently an asylum for many relict forms. Affinities with the flora of South Africa are not higher than those for other areas of the Australian Region. the Temperate Zone. The existing west-east affinities and discontinuities are discussed in relation to climatic changes. The Province is not regarded as the "cradle" of the autochthonous elements of the Australian flora though it is apparently an asylum for many relict forms. Affinities with the flora of South Africa are not higher than those for other areas of the Australian Region. The flora of Tasmania is not highly endemic at the generic level but it is of special interest because of certain affinities with the flora of Malaysia and with genera otherwise found along the Malaysia–New Zealand arc or genera also in South America. In some cases the genera are unknown on the mainland, in others they are known from Australian Tertiary deposits. The Tasmanian flora is considered to include (1) relicts from early Tertiary floras, (2) survivors from the cold climate regimes of the Pleistocene, and (3) Australian elements which have mingled with the flora during periods of land continuity. The North-East Queensland area is defined as including the high rainfall habitats of the eastern parts of Cape York Peninsula. An outstanding number of families, genera, and species are restricted to this area so far as the Australian Region is concerned. Many genera are limited to a single representative which may also occur in Malaysia. It is suggested that a proportion of these may be recent arrivals while others, known as fossils from southern deposits, have a more restricted distribution than in the past. The close affinity with the flora of New Guinea is obvious but there are certain affinities with the floras of New Caledonia and New Zealand which may be independent of those of other parts of the Australian Region. Consideration is given to the problems of migration of temperate elements between the northern and southern hemispheres and the passage of such elements through the tropical belt. The MacPherson–Macleay Overlap is defined as that area of eastern Australia where the Tropical and Temperate Zones overlap. It includes part of south-east Queensland and part of north-east New South Wales. Within this area tropical elements predominate in the wetter habitats of the eastern slopes of the ranges and temperate elements in the drier or cooler and more open sites. Many of the tropical elements are to be found in discontinuous areas to the south of the Overlap but there is no similar pattern of temperate communities to the north. The Overlap is of special interest in the discussion of discontinuous distributions in eastern Australia and the significance of these. The development of the Australian flora is discussed in Part C. Its present composition is regarded as primarily due to climatic selection both within the region and from the biotypes available as a result of migration. Migration by communities rather than by chance dispersal of individuals is considered a prime factor. Though the data concerning Tertiary floras are not extensive certain significant facts emerge. First there is a stronger affinity with the flora of South America and this must be contrasted with the marked lack of data suggesting a similarly increased relationship with southern Africa. The relationship between fossil and modern representatives of such genera as Podocarpus, Dacrydium, and Nothofagus suggests that there has been a northward migration or a withdrawal to warmer latitudes since the Tertiary. All the main elements of the present day flora are represented In the Tertiary assemblages. If current views on the "Malaysian" or "tropical" nature of some affinities and the "Antarctic" nature of others be accepted then there is no indication that the major migration into the Australian Region came from one particular direction. Possible climatic regimes and changes are discussed. It is suggested that the occurrence of cold pluvial conditions in southern Australia implies a contraction of the arid centre rather than a northward shift of the dry tropical belt. Under such circumstances northern Australia could still have enjoyed a warm wet climate. This opinion is supported by certain distribution patterns and by the pedological data concerning laterite formation. Apart from the Australian, Malaysian, and Antarctic elements in the Australian flora there are also temperate elements with northern hemisphere affinities. Some of these are found in temperate communities in both hemispheres but others are endemic to and characteristic of the Eremaean Zone. The Eremaean flora may have originated from a coastal sand dune and littoral type. It is suggested that it developed from elements that migrated to the Australian Region as early as the Cretaceous when there may have been a coastal continuity with the Tethys Sea. It is further postulated that these plants remained in coastal habitats but moved inland, possibly along southern estuarine coasts, and became isolated under arid conditions during the Pleistocene or Recent Times. The evidence is that eastern Australia has been a very important migration route for a very long period, being linked with the northern hemisphere through Malaysia. Northward migration of Australian elements has apparently been less successful than southward migration of Malaysian elements. It is considered that the ecological barrier formed by dense tropical communities must have inhibited northward movement of the light-requiring Australian types. The significance of such a barrier would be dependent on the climatic conditions during periods of land continuity between Australia and Malaysia and between Australia and New Guinea. Relationships between the Australian Region and Kew Zealand are either linked with those between Australia and South America, i.e. related to some unknown southern route, or they concern genera with distribution patterns involving New Guinea or New Guinea and New Caledonia. The opinion that Australia and New Zealand belong together in a biogeographic region is unacceptable unless such a, region includes a portion of the island arc in the north-east. The long-standing floristic relationship between Australia and Malaysia, a relationship which from geological evidence apparently extends back as far as the Cretaceous at least, coupled with the affinities among both fossil and modern plants with the flora of South America but not with southern Africa, militates against unqualified acceptance of any of the hypotheses, such as that of continental drift, which have been proposed to explain biological affinities between the major land masses. Plant distribution patterns are facts which can be demonstrated and at this stage of our knowledge further critical analysis is more important than the correlation between available facts and proposed explanations.