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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

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.

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.

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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.

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

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.

The Florida Caverns State Park, an area which is unique both in its flora and its physiography, is treated floristically with emphasis upon its geologlic history and past climates. Evidence is presented which supports the theory that the area has been continuously available for occupancy by plants throughout the period of Pleistocene glaciations, possibly since the deposition of early Pliocene alluvia. Discussions of disjunct and endemic populations of both vascular plants and mosses point out the importance of fluctuating glacial and interglacial climates as well as the significance of edaphic and genetic factors in the synthesis and preservation of the relic flora. Disjunction and endemism are also discussed in the light of recent collections in the southeastern United States, and distribution maps are provided for many species. A check list of the Bryophytes and an annotated check list of the vascular plants of the 1187-acre park supplement the text.

The study of chalk grassland in Northern France has evolved through three main phases. During the period from the early 19th century to the First World War, the general flora of Northern France was studied in some detail, but there was little ecological understanding of plant communities. Some workers, however, did attempt to group chalk grassland species ecologically, and the primitive concepts of plant sociology unconsciously developed. Between the wars, with the growth of plant sociology, chalk grassland studies became more elaborate. Specific associations were now described and the wider aspects of chalk grassland phytogeography considered. The post-war period has seen a great increase in botanical activity in Northern France. There have been many regional chalk grassland studies, all of which, in varying degrees, have employed the techniques of plant sociology. It may at last be possible to synthesise these studies, and to describe the chalk grassland associations of Northern France.

PHYTOGEOGRAPHY still presents many difficult problems, the final solution of some of which is extremely unlikely, though patient research will doubtless bring us much nearer the truth than we have yet reached. The latest comprehensive work on the subject (Grisebach's “Vegetation der Erde”) is a very good exposition of the existing distribution of plants, but it is nothing more. Since the promulgation of the theory of descent, however, the study of the dispersion of plants has entered upon a fresh phase, and it has received the attention of some of the ablest minds engaged in botanical pursuits; and with the ever-increasing geological evidence of the composition of the floras of former periods there is a good prospect of a real advance in this branch of science. Unfortunately there is a tendency to travel far beyond a point warranted by the evidence. This remark specially applies to the determination of many of the fossils of the earliest Tertiary times. Whether fresh discoveries will prove the correctness or the incorrectness of Unger's “New Holland in Europe,” we do not venture to predict, though we think the latter; but we agree with Saporta that most of the assumed determinations are better designated by such terms as affiliation and collocation (assimilation et rapprochement). Dr. Engler is not an unknown worker in phytogeography, for in his various monographs, especially in that of the genus Saxifraga, he has set forth the views which he, in some respectSj more fully elaborates in the work before us. The essay itself is preceded by thirty-six formulated leading ideas (leitende Ideen), which may, for our purpose, be reduced to one, namely, the relation of evolution and geological changes to distribution. Dr. Engler endeavours to trace the descent and migration of the vegetation of the regions under consideration since the Tertiary period by the aid of geological and recent evidence, but for various reasons he does not go back beyond the Miocene period. In his conception of the Miocene period he is in accord with Prof. Heer, who, he thinks, has easily refuted the arguments adduced by Mr. Starkie Gardner in support of his opinion that much of what Prof. Heer regards as Miocene is referable to the Eocene period. The author divides his subject into five sections and eighteen chapters. In the first section he treats of the development of the flora of North America from the Miocene period to the Glacial epoch; the second is devoted to the development of the flora of Eastern and Central Asia since Tertiary times; the third to the main features of the development of the Mediterranean flora since the Tertiary period; the fourth to the development of the high mountain flora before, during, and after the Glacial epoch; and the fifth to the consideration of the development of the floras of other countries influenced by the Glacial period. The map is constructed to show, as nearly as possible, the configuration of land and water in Tertiary times, the direction of the spreading and change of the vegetation during and after the gradual drying-up of the Tertiary seas, and the most important migratory routes of the Glacial plants. Disregarding the evolutionary element, which must necessarily be to a large extent purely speculative, Dr. Engler's essay is exceedingly interesting and instructive. The mere collocation of the facts bearing upon the subject renders it so, independently of the author's deductions therefrom. So far as the migratory part is concerned, it may be designated as an amplification, with some modifications, of the theory recently discussed by Dr. Asa Gray, Sir Joseph Hooker, Mr. Thiselton Dyer, and others. Dr. Engler does not find the contrast so great in the development of the Asiatic element in the vegetation of Eastern and Western North America, and there is no doubt of the existence of many more Asiatic types in Western North America than was formerly suspected. Diligent as the author has been in collecting evidence, he has overlooked some that he would have found useful. Thus at page 29 he seeks to explain the “extraordinarily interrupted distribution” of Monotropa uniflora and Phrymaleptostachya, both of which he assumes to be limited to the Himalayas, North-eastern Asia, and Eastern North America. Now Monotropa uniflora is common in North America west of the Rocky Mountains, as evidenced by specimens and collectors' notes in the Kew Herbarium; and it likewise occurs in Mexico, New Granada, Sachalin, and the Corea. The distribution of Phryma, too, is by no means so restricted as Dr. Engler supposes. But these are minor details which do not affect the main issues. Versuch einer Entwicklungsgeschichte der Pflanzenwelt, insbesondere der Florengebiete sett der Tertiadrperiode. Von Dr. Adolf. Engler. I. Theil. Die Extratropischen Gebiete der Nordlichen Hemisphare. Mit einer chromolithographischen Karte. 8vo. pp. 202. (Leipzig: Verlag von Wilhelm Engelmann, 1879.) Essay of a History of the Evolution of the Vegetable Kingdom, especially of the Floral Areas since the Tertiary Period. Part I.—The Extratropical Regions of the Northern Hemisphere.

Together with a number of collaborators I have made a detailed investigation of the differentiation of the flora and the distribution areas in one of the Aegean regions, the Cyclades. In this paper a few points of general interest concerning the phytogeography of this region are discussed, e.g. the „natural” vegetation, the distribution of rock plants, the explanation of the „Cycladian gap” in the distribution of some species.

The publication of the „Atlas of the British Flora“ at the end of April, 1962 will undoubtedly throw light on some old problems of British Phytogeography and at the same time pose many others. One of the major problems which has long presented itself is that of the Irish flora. At its simplest the problem can be defined as why do a number of species occur in Ireland which do not occur in Great Britain.

The History of the British Flora A Factual Basis for Phytogeography. By Dr. H. Godwin. Pp. viii + 384 + 26 plates. (Cambridge: At the University Press, 1956.) 90s. net.

FAO bibliography

FAO bibliography