论胡桃科植物的地理分布

 The present paper aims to discuss the geog raphical distribution of the Juglandaceae on the basis of unity of the phylogeny and the process of dispersal in the plants.       The paper is divided into the following three parts:       1.  The systematic positions and the distribution patterns of nine living genera in the family Juglandaceae (namely, Engelhardia, Oreomunnea, Alfaroa, Pterocarya, Cyclo- carya, Juglans, Carya, Annamocarya and Platycarya) are briefly discussed.  The evolu- tional relationships between the different genera of the Juglandaceae are elucidated. The fossil distribution and the geological date of the plant groups are reviewed.  Through the analysis for the geographical distribution of the Juglandaceous genera, the distribu- tion patterns may be divided as follows:       A.  The tropical distribution pattern       a. The genera of tropical Asia distribution: Engelhardia, Annamocarya.       b. The genera of tropical Central America distribution: Oreomunnea, Alfaroa.       B.  The temperate distribution pattern       c. The genus of disjunct distribution between Western Asia and Eastern Asia: Pterocarya.       d. The genus of disjunct distribution between Eurasia and America: Juglans.      e. The genus of disjunct distribution between Eastern Asia and North America: Carya.      f. The genera whose distribution is confined to Eastern Asia: Cyclocarya, Platy- carya.      2.  The distribution of species      According to Takhtajan’s view point of phytochoria, the number of species in every region are counted.  It has shown clearily that the Eastern Asian Region and the Coti- nental South-east Asian Region are most abundant in number of genera and species. Of the 71 living species, 53 are regional endemic elements, namely 74.6% of the total species. The author is of the opinion that most endemic species in Eurasia are of old endemic nature and in America of new endimic nature.  There are now 7 genera and 28 species in China, whose south-western and central parts are most abundant in species, with Pro- vince Yunnan being richest in genera and species.      3.  Discussions of the distribution patterns of the Juglandaceae A.       The centre of floristic region B.         The centre of floristic regions is determined by the following two principles:  a. A large number of species concentrate in a district, namely the centre of the majority; b.  Species of a district can reflect the main stages of the systematic evolution of the Juglandaceae, namely the centre of diversity.  It has shown clearly that the southern part of Eastern Asian region and the northern part of Continental South-east Asian Region (i.c. Southern China and Northern Indo-China) are the main distribution centre of the Juglandaceae, while the southern part of Sonora Region and Caribbean Region  (i.c. South-western U.S.A., Mexico and Central America) are the secondary distribution centre.       As far as fossil records goes, it has shown that in Tertiary period the Juglanda- ceae were widely distributed in northern Eurasia and North America, growing not only in Europe and the Caucasus but also as far as in Greenland and Alaska.  It may be considered that the Juglandaceae might be originated from Laurasia.  According to the analysis of distribution pattern for living primitive genus, for example, Engelhar- dia, South-western China and Northern Indo-China may be the birthplace of the most primitive Juglandaceous plants.  It also can be seen that the primitive genera and the primitive sections of every genus in the Juglandaceae have mostly distributed in the tropics or subtropics. At the same time, according to the analysis of morphological cha- racters, such as naked buds in the primitive taxa of this family, it is considered that this character has relationship with the living conditions of their ancestors.  All the evidence seems to show that the Juglandaceae are of forest origin in the tropical moun- tains having seasonal drying period.       B.  The time of the origin       The geological times of fossil records are analyzed. It is concluded that the origin of the Juglandaceae dates back at least as early as the Cretaceous period.       C.  The routes of despersal       After the emergence of the Juglandaceous plant on earth, it had first developed and dispersed in Southern China and Indo-China.  Under conditions of the stable tempera- ture and humidity in North Hemisphere during the period of its origin and development, the Juglandaceous plants had rapidly developed and distributed in Eurasia and dis- persed to North America by two routes: Europe-Greenland-North  America  route  and Asia-Bering Land-bridge-North America route.  From Central America it later reached South America.      D.  The formaation of the modern distribution pattern and reasons for this forma- tion.      According to the fossil records, the formation of two disjunct areas was not due to the origin of synchronous development, nor to the parallel evolution in the two con- tinents of Eurasia and America, nor can it be interpreted as due to result of transmis- sive function.  The modern distribution pattern has developed as a result of the tectonic movement and of the climatic change after the Tertiary period.  Because of the con- tinental drift, the Eurasian Continent was separated from the North American Conti- nent, it had formed a disjunction between Eurasia and North America. Especially, under the glaciation during the Late Tertiary and Quaternary Periods, the continents in Eu- rasia and North America were covered by ice sheet with the exception of “plant refuges”, most plants in the area were destroyed, but the southern part of Eastern Asia remained practically intact and most of the plants including the Juglandaceae were preserved from destruction by ice and thence became a main centre of survival in the North Hemisphere, likewise, there is another centre of survival in the same latitude in North America and Central America.      E.  Finally, the probable evolutionary relationships of the genera of the Juglanda-ceae is presented by the dendrogram in the text.     

我国最早的植物学辞典——《全芳备祖》简介

 The “Quan Fang Bei Zu”, a first dictionary for Chinese plants, which contains 27 volumes in its first collection and 31 volumes in its second collection, was completed by Chen Jing-yi in 1253, the First Year of Bao You of Li Zong in Song Dynasty.  The first part of this encyclopaedia of plants is devoted to flowers.  The second part is of more varied nature, dealing with fruit trees, plants in general, herbs, trees, agriculture and sericulture, vegetables, and medicinal herbs.  These two collections cover 267 kinds of plants, each of which is described under two categories separately: The first category, “Si Shi Zu” in Chinese, meaning “facts of the plants” concerned, which again divided into 3 entries, i.e. the history, miscellaneous information and sundry bits of the plants. The second category, “Fu Yong Zu” in Chinese, meaning poetry, which divided into 10 meters, wherein the plants are described and eulogized in poetrical expressions.      Later on, the “Quan Fang Bei Zu” was used as a blueprint for some famous books in China, for example, the “Qun Fang Pu” and the “Guang Qun Fang Pu” all written and compiled after its model.  It is known today that in China there are only two extant hand writting copies of it, one in Beijing Library, the other in the Library of Yunnan University.  Both of them are listed as the best national books. Outside China, it is known that a third copy of is in the Congress Library in U.S.A.  As for the ori- ginal wood-carving copy printed during the period of the Song Dynasty, it is known so far that one copy is kept in the Library of Culture Ministry of Japan.  The Beijing Agriculture Publishing House has made a decision to photograph this carved copy in the Culture Ministry of Japan as one of the “Precious Series of China Agriculture Science”.  The book plays a very important role in the study of chinese botany, agri-culture science, medicine, history and literature.     

木兰科分类系统的初步研究

A new system of classification of Magnoliaceae proposed.  This paper deals mainly with taxonomy and phytogeography of the family Magnoliaceae on the basis of external morphology, wood anatomy and palynology.  Different  authors have had different ideas about the delimitation of genera of this family, their controversy being carried on through more than one hundred years (Table I).  Since I have been engaged in the work of the Flora Reipublicae Popularis Sinicae, I have accumulated a considerable amount of information and material and have investigated the living plants at their natural localities, which enable me to find out the evolutionary tendencies and primitive morphological characters of various genera of the family.  According to the evolutionary tendencies of the characters and the geographical distribution of this family I propose a new system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law (1979), two tribes, Magnolieae and Michelieae Law, four subtribes, Manglietiinae Law, Magnoliinae, Elmerrilliinae Law and Micheliinae, and fifteen genera (Fig. 1 ), a system which is different from those by J. D. Dandy (1964-1974) and the other authors.      The recent distribution and possible survival centre of Magnoliaceae. The members of Magnoliaceae are distributed chiefly in temperate and tropical zones of the Northern Hemisphere, ——Southeast Asia and southeast North America, but a few genera and species also occur in the Malay Archipelago and Brazil of the Southern Hemisphere. Forty species of 4 genera occur in America, among which one genus (Dugendiodendron) is endemic to the continent, while about 200 species of 14 genera occur in Southeast Asia, of which 12 genera are endemic.  In China there are about 110 species of 11 genera which mostly occur in Guangxi, Guangdong and Yunnan; 58 species and more than 9 genera occur in the mountainous districts of Yunnan.   Moreover,  one  genus (Manglietiastrum Law, 1979) and 19 species are endemic to this region.  The family in discussion is much limited to or interruptedly distributed in the mountainous regions of Guangxi, Guangdong and Yunnan.  The regions are found to have a great abundance of species, and the members of the relatively primitive taxa are also much more there than in the other regions of the world.      The major genera, Manglietia, Magnolia and Michelia, possess 160 out of a total of 240 species in the whole family.  Talauma has 40 species, while the other eleven genera each contain only 2 to 7 species, even with one monotypic genus.   These three major genera are sufficient for indicating the evolutionary tendency and geographical distribution of Magnoliaceae.  It is worthwhile discussing their morphological  characters  and distributional patterns as follows:      The members of Manglietia are all evergreen trees, with flowers terminal, anthers dehiscing introrsely, filaments very short and flat, ovules 4 or more per carpel.  This is considered as the most primitive genus in subtribe Manglietiinae.  Eighteen out of a total  of 35 species of the genus are distributed in the western, southwest to southeast Yunnan. Very primitive species, such as Manglietia hookeri, M. insignis  and M. mega- phylla, M. grandis, also occur in this region. They are distributed from Yunnan eastwards to Zhejiang and Fujian through central China, south China, with only one species (Manglietia microtricha) of the genus westwards to Xizang.  There are several species distributing southwards from northeast India to the Malay Archipelago (Fig. 7).      The members of Magnolia are evergreen and deciduous trees or shrubs, with flowers terminal, anthers dehiscing introrsely or laterally, ovules 2 per carpel, stipule adnate to the petiole.  The genus Magnolia is the most primitive in the subtribe Magnoliinae and is the largest genus of the family Magnoliaceae. Its deciduous species are distributed from Yunnan north-eastwards to Korea and Japan (Kurile N. 46’) through Central China, North China and westwards to Burma, the eastern Himalayas  and northeast India.  The evergreen species are distributed from northeast  Yunnan  (China)  to  the Malay Archipelago.  In China there are 23 species, of which 15 seem to be very primi- tive, e.g. Magnolia henryi, M. delavayi, M. officinalis and M. rostrata, which occur in Guangxi, Guangdong and Yunnan.      The members of Michelia are evergreen trees or shrubs, with flowers axillary, an- thers dehiscing laterally or sublaterally, gynoecium stipitate, carpels numerous or few. Michelia is considered to be the most primitive in the subtribe Micheliinae, and is to the second largest genus of the family.  About 23 out of a total of 50 species of this genus are very primitive, e.g. Michelia sphaerantha, M. lacei, M. champaca,  and  M. flavidiflora, which occur in Guangdong, Guangxi and Yunnan (the distributional center of the family under discussion)  and extend eastwards to Taiwan  of  China, southern Japan through central China, southwards to the Malay Archipelago through Indo-China. westwards to Xizang of China, and south-westwards to India and Sri Lanka (Fig. 7).      The members of Magnoliaceae are concentrated in Guangxi, Guangdong and Yunnan and radiate from there.  The farther away from the centre, the less members we are able to find, but the more advanced they are in morphology.  In this old geographical centre there are more primitive species, more  endemics  and  more monotypic genera. Thus it is reasonable to assume that the region of Guangxi, Guangdong and Yunnan, China, is not only the centre of recent distribution, but also the chief survival centreof Magnoliaceae in the world.     

云南丽藻族新植物

 Yunnan is extends across the subtropical and tropical zones, situated in the sou- thern border area of southwestern China.  This district is extremely rich in plants, and thus, it has been known as a “Kingdom of Plants”.  However, up to the present our knowledge of the Charophyta in this region has been scanty.      In order to get a thorough understanding of its Charophyta, we identified speci- mens collected from 13 countries or cities in this province.  The result shows that is especially abundant in Charophyta.      In this paper, however, only are reported new species, new varieties and new re- cords of China on the Nitelleae.  The former two are Nitella hokouensis, N. bicornuta, N. longicaudata, N. procera, N. brevidactyla, N. papillata, N. pseudohyalina, N. hyalina var. aberrans and Tolypella yunnanensis; while the third is Nitella globulifera Pal andN. japonica T. F. Allen.     

茶树品种分类的探讨

  It is generally accepted that tea plant (Thea sinensis L.) is originated in China, where has numerous varieties,  According to the literature, the selected work of tea plants may be traced as early as to the 3rd-5th century A.D.  The number of varie- ties discovered in recent years reached more than 300.  Besides, a large number of wild species were discovered. In all tea varieties, the crown canopy, leaf size and the date of sprouting were different.  It was proposed that according to the crown canopy, leaf size and the date of sprouting.   The  principle of the classification  of Chinese tea varieties may be 3 orders.  The first order named “group”, it contains macrophanerophyte group, microphanerophyte group, and frutex group.  The second order named “type”, it contains extreme large leaf size, large leaf size, medium leaf size and small leaf size.  The third order named “species”, it contains the early- sprouting species, medium-sprouting species and late-sprouting species.       

我国悬钩子属植物的研究

 The genus Rubus is one of the largest genera in the Rosaceae, consisting of more than 750 species in many parts of the world, of which 194 species have been recorded in China.      In the present paper the Rubus is understood in its broad sense, including all the blackberries, dewberries and raspberries, comprising the woody and herbaceous kinds. So it is botanically a polymorphic, variable and very complicated group of plants. The detailed analysis and investigation of the evolutionary trends of the main organs in this genus have indicated the passage from shrubs to herbs in an evolutionary line, although there is no obvious discontinuity of morphological characters in various taxa. From a phylogenetic point of view, the Sect. Idaeobatus Focke is the most primitive group, characterized by its shrub habit armed with sharp prickles, aciculae or setae, stipules attached to the petioles, flowers hermaphrodite and often in terminal or axill- ary inflorescences, very rarely solitary, druplets separated from receptacles. Whereas the herbaceous Sect.  Chamaemorus L. is the most advanced group, which is usually unarmed, rarely with aciculae or setae, stipules free, flowers dieocious, solitary, dru- plets adhering to the receptacles and with high  chromosome numbers  (2n = 56). Basing upon the evolutionary tendency of morphological  features,  chromosome nu- mbers of certain species recorded in literature and the distribution patterns of species, a new systematic arrangement of Chinese Rubus has been suggested by the present authors. Focke in his well-known monograph divided the species of Rubus into  12 subgenera, while in the Flora of China 8 sections of Focke were adapted, but some im- portant revisions have been made in some taxa and Sect. Dalibarda Focke has been reduced to Sect.  Cylactis Focke.  In addition, the arrangement of sections is presented in a reverse order to those of Focke’s system.  The species of Rubus in  China are classified into 8 sections with 24 subsections (tab. 3) as follows: 1. Sect. Idaeobatus, emend. Yü et Lu(11 subsect. 83 sp.); 2. Sect. Lampobatus Focke (1 sp.); 3. Sect. Rubus (1 sp.); 4. Sect. Malachobatus Focke, emend. Yü et Lu (13 subsect. 85 sp.); 5. Sect. Dalibardastrus (Focke)Yü et Lu (10 sp.); 6. Sect. Chaemaebatus Focke (5 sp.); 7. Sect. Cylactis Focke, emend. Yü et Lu (8 sp.); 8. Sect. Chamaemorus Focke (1 sp.).      In respect to the geographical distribution the genus Rubus occurs throughout the world as shown in tab. 2, particularly abundant in the Northern Hemisphere, while the greatest concentration of species appears in North America and E. Asia.  Of the more than 750 species in the world, 470 or more species (64%) distributed in North America.  It is clearly showm that the center of distribution lies in North America at present time.  There are about 200 species recorded in E. Asia, of which the species in China (194) amount to 97% of the total number. By analysis of the distribution of species in China the great majority of them inhabit the southern parts of the Yangtze River where exist the greatest number of species and endemics,  especially in south- western parts of China, namely Yunnan, Sichuan and Guizhou (tab. 3. 4.).  It is in- teresting to note that the centre of distribution of Rubus in China ranges From north- western Yunnan to south-western Sichuan (tab. 5), where the genus also reaches its highest morphological diversity.       In this region the characteristics of floristic elements of Rubus can be summarized as follows: it is very rich in composition, contaning 6 sections and 94 species, about 66% of the total number of Chinese species; there are also various complex groups, including primitive, intermediate and advanced taxa of phylogenetic importance; the proportion of endemic plants is rather high, reaching 61 species, up to 44% of the total endemics in China.  It is noteworthy to note that the most primitive Subsect. Thyrsidaei (Focke) Yü et Lu, consisting of 9 endemic species, distributed in southern slopes of the Mts. Qin Ling and Taihang Shan (Fig. 4). From the above facts we may concluded that the south-western part of China is now not only the center of distribu- tion and differentiation of Rubus in China, but it may also be the center of origin ofthis genus.     

中国丛菔属的分类

 The genus Solms-Laubachia of Cruciferae was established by Muschler in 1912 on the basis of the Chinese species Solms-Laubachia pulcherrima of Yunnan Province. Since then, nine species, two varieties and two forms have been recorded.  They are almost all endemic in China except one species—Solms-Laubachia retropilosa Botsch. which was discovered in Sikkim.      We described in this paper thirteen species, three varieties and one form, of which, we suppose, three species, one variety and one combination have never been reported before.  Most species grow in the mountainous regions of Szechuan, Yunnan, Tibet,Ching-hai and Sinkiang in China.     

中国列当属的分类及与近缘属的关系

The morphological characters in the genus Orobanche were evaluated from the taxonomic point of view.  The author finds that the plants of this genus are relatively similar to each other in respect to characters of vegetative organs, fruits and seeds.  But the differences in the floral structures can be served as a basis for delimitating infrageneric taxa.   The seed coat of 18 species and pollen grains of  6 species were also examined under scanning electron microscope (SEM). They seem to have little significance for distinguishing species.       The result supports G. Beck’s (1930) division of the genus Orobanche into 4 sections, of which 2 occur in China, based on the characters of the inflorescence, bracteoles and calyx. The author considers that some characters, such as anther hairy or not, upper lip of corolla entire or not, lower lip longer or shorter than the upper one, the state of corolla-tube inflec-  tion and the hair type of filaments and plants, are important in distinguishing Chinese species.  A key to the species of Orobanche in China is given.       This genus consists of about 100 species, and is mostly confined to Eurasia, with over 60  species found in Caucasus and Middle Asia of USSR, where may be the mordern  distribu-  tional  centre.        Orobanche L. in China is represented by 23 species, 3 varieties and l forma. As shown in  Table 1, most species (12 species) are found in Xinjiang, which clearly shows a close floristic  relationship between this region and Middle Asia of USSR.  6 species are endemic to China,  of which 4 are confined to the Hengduan Mountains  (Yangtze-Mekong-Salwin divide).        The relationships between this genus and related ones of Orobanchaceae are also discussed.  The author holds the following opinions: the genus Phelypaea Desf. should be considered as a   member of Orobanche L. Sect. Gymnocaulis G. Beck,  the monotypic genus,   Necranthus A.   Gilli endemic to Turkey, is allied with Orobanche L. Sect.  Orobanche, the monotypic genus,   Platypholis Maxim, endemic to Bonin Is. of Japan, is far from Orobanche L. in relation and   should be regarded as a separate genus.        The 11 OTU’s, including all the sections of Orobanche L. and 7 genera of Orobanchaceae,   and 15 morphological characters were used in the  numerical  taxonomic treatment  to  test  the   above-mentioned  suggestions.   After standardization of characters, the correlation matrices were   computerized.  The correlation matrices were made to test the various clustering methods.   At    last the UPGMA clustering method was chosen and its result is shown in a phenogram.  The   result of numerical analysis is basically in accordance with the suggestions.     

西藏菊科植物

 1)  The Compositae in Tibet so far known comprise 508 species and 88 genera, which nearly amounts to one fourth of the total number of genera and one third of the total number of species of Compositae in all China, if the number of 2290 species and 220 genera have respectively been counted in all China. In Tibet there are all tribes of Com- positae known in China, and surprisingly, the large tribes in Tibetan Compositae are also large ones in all China and the small tribes in Tibet are also small ones in all China. Generally speaking, the large genera in Tibet are also large ones in all China and the small genera in Tibet are likewise small ones in all China. In this sense it is reasonable to say that the Compositae flora of Tibet is an epitome of the Compositae flora of all China.      In the Compositae flora of Tibet, there are only 5 large genera each containing 30 species or more. They are Aster, Artemisia, Senecio, Saussurea and Cremanthodium. And 5 genera each containing 10—29 species. They are Erigeron, Anaphalis, Leontopodium, Ajania, Ligularia and Taraxacum. In addition, there are 77 small genera, namely 87% of the total of Compositae genera in Tibet, each comprising 1—9 species, such as Aja-niopsis, Cavea and Vernonia, etc.      2)  The constituents of Compositae flora in Tibet is very closely related to those of Sichuan-Yunnan provinces with 59 genera and 250 species in common. Such a situation is evidently brought about by the geographycal proximity in which the Hengtuang Shan Range links southeastern and eastern Tibet with northern and northwestern Sichuan- Ynnnan.  With India the Tibetan Compositae have 59 genera and 132 species in common, also showing close floristic relationships between the two regions. Apparently the floris- tic exchange of Compositae between Tibet and India is realized by way of the mountain range of the Himalayas.  The mountain range of the Himalayas, including the parallel ranges, plays a important role as a bridge hereby some members of the Compositae of western or northern Central Asia and of the northern Africa or of western Asia have migrated eastwards or southeastwards as far as the southern part of Fibet and northern part of India, or hereby some Compositae plants of eastern and southeastern Asia or Asia Media have migrated northwestwards as the northern part of Central Asia.      Some of the species and genera in common to both Tibet and Sinjiang indicate that this weak floristical relationship between these regions is principally realized through two migration routes: one migration route is by way of the Himalayas including the parallel ranges to Pamir Plataeu and Tien Shan, or vice versa. The other migration route is by way of northern Sinjiang to Mongolia, eastern Inner Mongolia, southwards to Gansu, Qinghai (or western Sichuan), eastern Tibet up to the Himalayas, or vice versa.      However, Tibet is not entirely situated at a migration crossroad of the floral ele- ments. An ample amount of the data shows that Compositae flora have a particular capability of development in Tibet. of the total number of species of Tibetan Com- positae, 102 species and 1 genus (Ajaniopsis Shih) are endemic. Besides, 8 genera are re- gional endemics with their range extending to its neighbourhood. The higher percentage of endemics at specific level than at generic in Tibetan Compositae may be a result of active speciation in response to the new enviromental conditions created by the uplifting of the Himalayas.  The flora in Tibetan Plateau as a whole appears to be of a younger age.       3) The uprising of the Himalayas and of the Tibetan Plateau accompanied by the ultraviolet ray radiation, the microthermal climate and the high wind pressure has, no doubt, played a profound influence upon the speciation of the native elements of Tibetan Compositae. The recent speciation is the main trend in the development of the Com-positae flora native in Tibet in the wake of upheaval of the plateau.     

中国梅花衣属的初步研究

 Parmelia is a genus of economical importance.   According  what  was  recorded, Meyen & Flotow were the first foreigners to study Chinese lichens in 1843.  Up to the present time 74 species, 24 varieties and 11 forms have been described from China.      The majority of specimens reported in this paper were collected by many Chinese botanists and collectors from 21 provinces from 1928--1962, while a few of them were collected by Licent from 1916 to 1917 and by Poliansky in 1957.      The system of classification adopted here is that held by A. Zahlbruckner in 1926. But in section Hypotrachyna, the two subsections-Myelochroa and Myeloleuca proposed by Asahina are adopted and Parmelia xanthocarpa which has not been properly placed before, is here referred to the subsection Myelochroa.      In the subgenus Hypogymnia the writer discovers that the length of spores of two species are longer than 10μ, especially  Parmelia macrospora reaches  17.5μ long.  So far as the writer knows, the upper limitation of the spore length  recognized  by  many lichenologists has been 10μ in this subgenus.  The spore measurement of this subgenus needs, therefore, to be revised in future.       In this paper 78 species, 14 varieties and 6 forms are presented.  Among them, 5 species, 5 varieties and 1 forms are considered as new and two new combinations have been made.  Out of all these, 31 species, 6 varieties and 2 forms are first recorded from China.  All the materials cited are deposited in the Mycological Herbarium of Instituteof Microbiology, Academia Sinica, Peking.     

中国清风藤科的初步研究

 This paper is a preliminary study on the Sabiaceae in aspects of its morphology, taxonomy and geography.  We propose that the Sabioideae and Meliosmoideae as two new subfamilies of Sabiaceae according to the external morphology, flower structure and geographical distribution of these two genera respectively.       This paper follows the taxonomic concepts of Luetha Chen on Sabia and C. F. van Beusekom on Meliosma.  We agree with them for their classification of these two genera above the specific rank.  As to the revision work of Sabia by van de Water and C. F. van Beusekom’s work on Meliosma we disagree  for their unduly broad specific concepts.  We rather treat the species of these two genera according to their habitats in regions on a relatively narrower sense.  The genus Sabia of China are classified into 2 tribes, with 16 species, 5 subspecies and 2 varieties in which 4 sub- species and l variety are as new combinations, the genus of Meliosma in China are classified into 2 subgenera with 29 species, and 7 varieties of which 4 varieties are new combinations.       After examining the affinity of the species of Sabia and Meliosma in China and its neighboring nations such as Burma, Japan and Bhutan, we found that their migra- tion initiated from China, as the primitive species of these two genera occured in northeast and central part of Yunnan, sou theast of Sichuan, north of Guizhou and west of Hubei, the region may probably be the main origin of these two genera.      As shown in tables 1 & 2, the localities where the species of these two genera den- sely populate they are from Yunnan, Guangxi, and Guangdong coinciding with the concepts of C. F. van Beusekom and van de Water about the distribution of exotic species of these two genera, it may reasonable be pointed out that the center of distri- bution of these two genera is Yunnan, Guangxi, Guangdong and nieghboring nations, upper Burma and northern Vietnam.  Futhermore, it may be seen that starting from this center the number of species become less and less as they proceed far and far awaybut become more advance in evolution.     

论世界柳属植物的分布和起源

1.  The distribution of Salix species among the continents.  There are about 526 species of Salix in the world, most of which are distributed in the Northern Hemisphere with only a few species in the Southern Hemisphere.  In Asia, there are about 375 species, mak- ing up 71.29 percent of the total in the world, including 328 endemics; in Europe, about 114 species, 21.67 percent with 73 endemics; in North America, about 91 species, 17.3 percent with 71 endemics; in Africa, about 8 species, 1.5 percent, with 6 endemics.  Only one species occurs in South America.  Asia, Europe and North America have 8 species in common (excluding 4 cultivated species).  There are 34 common species between Asia and Europe, 14 both between Europe and North America and between Asia and North America, 2 between Asia and Africa. Acording to the Continental Drift Theory, the natural circumstances which promoted speciation and protected newly originated and old species were created by the orogenic movement of the Himalayas in the middle and late Tertiary.  Besides, the air temperature was a little higher in Asia than in Europe and North America (except its west part) and the dominant glaciers were mountainous in Asia during the glacial epoch in the Quaternary Period.  Then willows of Eu- rope moved southwards to Asia.  During the interglacial period they moved in opposite direc- tion.  Such a to-and-fro willow migration between Asia and Europe and between and North America occurred so often that it resulted in the diversity of willow species in Asia.  Those species of willows common among the continents belong to the Arctic flora.      2.  The multistaminal willows are of the primitive group in Salix.  Asia has 28 species of multistaminal willows, but Europe has only one which is also found in Asia.  These 28 species are divided into two groups, “northern type” and “southern type”, according to morphology of the ovary.  The boundary between the two forms in distribution is at 40°N.  The multistami- nal willows from south Asia, Africa and South America are very similar to each other and may have mutually communicated between these continents in the Middle or Late Cretaceous Period.  The southern type willows in south Asia are similar to the North American multista- minal willows but a few species.  The Asian southern type willows spreaded all over the conti- nents of Europe, Asia and North America through the communication between them before the Quaternany Period.   Nevertheless, it is possible that the willows growing in North America immigranted through the middle America from South America.  The Asian northern type mul- tistaminal willows may have originated during the ice period.      The multistaminal willows are more closed to populars in features of sexual organs.  They are more primitive than the willows with 1-3 stamens and the most primitive ones in the ge- nus.      3.  The center of origin and development of willows Based on the above discussion it is re- asonable to say that the region between 20°-40°N in East Asia is the center of the origin and differentiation of multistaminal willows.  It covers Southern and Southwestern China and nor- thern Indo-China Pennisula.