From standpoint of floristic division, Sichuan is located in the middle part of Eastern Asiatic Region (Takhtajan 1978) or is the area where Sino-Himalayan Forest Subkingdom and Sino-Japan Forest Subkingdom meet (wu 1979). Here exist many socalled Arcto-Tertiary elements and newly originated species or races. In order to bring the light the origin and differentiation of Eastern Asiatic elements, cytological investigation on plants of this region are very significant. The materials of the following 5 species were collected on Mt. Emei in Sichuan Province. Voucher specimens are kept in CDBI. 1. Toricellia angulata Oliver var. intermedia (Harms) Hu PMC meiotic examination revealed n = 12 at diakinesis (Pl. I fig. 9) Toricellia, consisting of 2 spp., is endemic to Eastern Asiatic Region. Based on our result along with the report of Toricellia tiliifolia (Wall.) DC. (2n=24) by Kurosawa (1977), we argue that the basic chromosome number of Toricellia is 12. Many authors, such as Airy-Shaw (1973), Dahlgren (1975, 1977), Takhtajan (1969, 1980), Thorne (1983), have adopted Hu’s (1934) treatment erecting it as a monotypic family Toricelliaceae. Its systematic position, whether closer to Cornaceae than to Araliaceae or vice versa, has been in dispute. Cytologically it seems closer to Araliaceae, as shown anatomically (Lodriguez 1971), because the basic chromosome number of Cornaceae s. 1. is x=11, 9, 8 (Kurosawa 1977), whereas that of Araliaceae is 12 (Raven 1975). 2. Cardiocrinum giganteum (Wall.) Makino Somatic chromosome number, 2n=24 was determined from root-tip cells (Ph. I. fig. 8). Cardiocrinum (Endl.) Lindl., consisting of 3 spp., is endemic to Eastern Asiatic Region. C. giganteum (Wall.) Makino is distributed from Himalayan region to S. W. China. The present report is in accord with the number reported by Kurosawa (1966) who got the material from Darjeeling of India. However the karyotype of the present plant is slightly different from that given by Kurosawa. In the present material, the satellites of the 1st. pair of chromosomes and the short arms of llst. pair of chromosomes are visibly longer than those of Kurosawa’s drawing (fig. 1, 2) The plants from Yunnan, Sichuan and Hubei Provinces, named as C. giganteum var. yunnanense (Leitchtlin ex Elwes) Stearn, differ slightly from those of Himalayan region also in outer morphological characters. The taxon needs both cytological and taxonomical further studies. 3. Disporum cantoniense (Lour.) Merr. PMC meiotic examination revealed n=8 at diakinesis (Pl. I. fig. 6) This species is widely distributed from Himalayan region through Indo-China to our Taiwan Province and Indonesia. Three cytotypes (2n=14, 16, 30) were reported for the taxon including its variety, var. parviflorum (Wall) Hara, by various authors (Hasegawa 1932, Mehra and Pathamia 1960, Kurosawa 1966, 1971 Mehra and Sachdeva 1976a). Some authors consider D. pullum Salisb. and D. calcaratum D. Don as synonyms of D. cantoniense. So D. cantoniense may be a species aggregate with different extreme races. Sen (1973a, b.) reports that the somatic chromosome numbers of D. pullum and D. calcaratum from Eastern Himalayan region are 14, 16, 28, 30, 32. He also discovered that chromosome alterations in species of Disporum involve not only the number but the structure as well. He found that in species of Liliaceae where the reproduction is mainly vegetative, polysomaty often occurs. In China we have not only D. cantoniense and D. calcaratum but also D. brachystomon Wang et Tang which is similar to D. cantoniense var. parviflorum (Wall.) Hara. These taxa need further critical studies. 4. Paris fargesii Franch. PMC meiotic examination revealed n=5+2B (Voucher no. 112) or n=5 (Voucher no. 62) at MI and AI (Pl. I. fig. 1. 4. 5.). This is the first report for the species. A bridge and a fragment were also observed at AI. Paris polyphylla Smith is extraordinarily polymorphic species. Hara (1969) regards all chinese extreme forms, such as P. fargesii Franch., P. violacea Lévl., P. pubescens (Hand. -Mzt.) Wang et Tang, etc. as infraspecific taxa of P. polyphylla. Needless to say, the various races of P. polyphylla Smith in China need further critical studies and are good material for further study to understand the speciation. 5. Reineckia carnea(Andr.) Kunth Reineckia is a monotypic genus endemic to Eastern Asiatic Region. In the present material somatic chromosome number in root-tip cells is determined as 2n=38 (Pl. I. fig. 7). According to the terminology defined by Levan et al., the karyotype formula is 2n=28 m+10 sm. The length of chromosomes varies from 14.28 μ to 5.5 μ. The idiogram given here (fig. 3) is nearly the same as that presented by Hsu et Li (1984). The same number has been previously reported by several authors, Noguchi (1936), Satô (1942), Therman (1956). The karyotype is relatively symmetrical (2B, accorling to the classi-fication of stebbins 1971) in accord with the opinion of Therman (1956).

The Rosaceae is one of the five largest families of Xizang flora, consisting of 30 genera with 242 species, the total number of species is slightly less than those of Compositae, Graminae, Leguminosae and Ericaceae in Xizang, amounting to 62.5% of the total number of genera and 28% of the total number of species of the rosaceous flora in China. The four subfamilies of Rosaceae including primitive, intermediate and advanced groups have been found in Xizang. These groups consist of 11 types of floristic elements, i.e. 4 genera belong to cosmopolitan, 9 genera belong to North Temperate, 3, E. Asian-N. American, 3 Sino-Himalayan, 3 Sino-Japanesa, 2 Old World Temperate, 1 Temperate Asian, 2 Mediterranean-W. and O. Asian, 1 C. Asian, I Tropical Asian and 1 endemic to China. It is obvious that Rosaceae in Xizang comprises holarctic, Ancient Mediterranean and paleotropical elements, among which the temperate components are the most dominant. The characteristics of the floristic composition of Rosaceae in Xizang may be summarized as follows: (1) Xizang abounds in both genera and species of the family which are diverse in forms, including the primitive, intermediate and advanced groups, (2) The geographical elements are rather complex, mostly belonging to the temperate, among which the Sino- Himalayan components and the elements endemic to China are dominant, (3) The proportion of plants endemic to China and distributed in Xizang is much higher than those endemic to Xizang itself, but there exist newly arisen species and infraspecific forms or varieties which show that the speciation is apparently still active in Xizang. The rosaceous flora of Xizang is a combination of old and new floristic elements, based on the old floristic components, affected by the upheaval of the Himalayas, the differentiation and speciation have been taking place in the long history. The geographical distribution of Rosaceae in Xizang may be divided into 5 regions, i.e. the northeastern, southeastern, southern, northwestern and northern. The rosaceous plants are most abundant in the southeastern area, next in southern area, fewer in the northeastern and very rare in the northwestern and northern regions. The general tendency of the distribution of Rosaceae in Xizang is that the number of species gradually decreases from the southeast to the northwest and the habit gradually changes from trees, shrubs and herbaceous plants in the southeast to cushion-like scrubs and dwarf perennial herbs in the northwest. These facts clearly show that the uplift of the Himalayas has deeply affected the phytogeographical distribution of Xizang Rosaceae. The rosaceous flora of Xizang has close relationships with those of the adjoring regions, i.e. Yunnan and Sichuan. Besides, it is connected with floras of Nepal, Sikkim, Bhutan nothern Buram and nothern India, but silghtly influenced by the Ancient Mediterranean flora.

By means of SDS linear gradient polyacrylamide gel electrophoresis, seed protein peptides of 50 species belonging to 10 genera of Pinaceae were analysed. A major peptide possessing molecular weight about 45000 daltons is shared by every species in Pinaceae. There are many peptides of higher molecular weight in seeds, but their content is very low. In order to make a series of quantitative comparisons between any two taxa, we define “peptide distance” as follows: number of different peptides between 2 taxa peptide distance= ----------- total number of peptides in 2 taxa In the following table, the peptide distances of some genera are shown together with other molecular data about Pinaceae.

genus	ancientry of genus	antigen distance	zymogram distance	peptide distance
Larix	Miocene to now (25My)	0	0	0.08
Cedrux Pseudotsuga Keteleeria	Oligocene to now (35My)	_ _ _	0 0.17 0.29	_ _ _
Tsuga Abies	Eocene to now (57My)	1.0 _	_ 0.44	_ 0.35
Picea	Late Cretaceous-(67-100 My)	0.5	0.30	0.18
Pinus	Early Cretaceous-(100-130My)	2.3	0.67	0.39

From the data cited above, there are positive correlation between molecular data and the ancientry of genera in Pinaceae. Therefore, the rate of molecular evolution seems stable. Based on the data of peptide distances, it is suggested that the variation be discontinuous between the genera, but continuous within a genus. A comparison between molecular and morphological evolution indicates that the two evolutions are different not only in rate but in mechanism as well.

Pollen morphology of 44 species representing 9 genera of Tiliaceae in China was examined under light microscope, 10 of them were observed with scanning electron microscope. Nine genera involved in this paper are: Colona. Corchoropsis, Corchorus, Excentrodendron, Grewia, Hainannia, Microcos, Tilia and Triumfetta The pollen grains of Tiliaceae are eurypalynous. Based on the aperture type and ornamentation, they may be grouped into four types: (1) The Grewia type, pollen grains tricolporate: Colona, Corchorus, Grewia, Microcos and Triumfetta, (2) The Tilia type, pollen grains brevitricolporate: Hainania and Tilia, (3) The Corchoropsis type, pollen grains triporate, spinate: Corchoropsis, and (4) The Excentrodendron type, pollen grains triporate, reticulate: Exce ntrodendron. The significance of pollen morphology in taxonomy of Tiliaceae is discussed. The palynological data seem to support the separation of Microcos from Grewia and the transfer of Corchoropsis to Sterculiaceae from Tiliaceae.

This paper deals with chromosomal numbers and morphology of 10 species of Aconitum in China. According to the basic number of the genus (x=8), these species can be referred to diploid, tetraploid, hexaploid and octoploid. Correlation is found between chromosomal numbers, sizes and structures. The perennial species with a rhizome are mostly diploid, with chromosomes larger than those in the biennial species with a tuber, and their chromosome pairs 3-7 are mostly subterminal ones, whereas most biennial species are polyploid, and their chromosome pairs 3-7 are almost submetacentric. The evolutionary trends of chromosome from diploid to polyploid, large to small, st to sm are considered possible. The data are agreed with the idea that rhizomal species are more primitive than tuberous ones. The existence of two types of karyotypes in these 10 species is a further support of taxonomic division of two subgenera, subgen. Paraconitum and subgen. Aconitum. In addition, some species are taxonomically discussed.

The present paper is the Supplement 2 to the Flora of Xizang, based upon a collection in 1980 by Mr. W. L. Chen et al. from Mêdog, the south-eastern part of Xizang. In the paper 11 new species are desribed and 10 new-record species are reported. All the type specimens are kept in the Herbarium of the Institure of Botany, Academia Sinica (PE).

eterachopsis was proposed by the senior author as an independent genus of the family Aspleniaceae in 1940 with 2 species. Since then much study on its morphology, anatomy, gametophyte and palynology has been carried out by Nayar, Bir, Chandra & Nayar and Chang et al., and they are of the opinion that the genus like Ceterach, is a comparatively primitive element in the family Aspleniaceae. The queer zigzag patern of cutting of lanceolate fronds appears extraordinary in the family Aspleniaceae, and also suggests its antiquity in evolution. So far only 3 species (C. dalhousiae, C. paucivenosa and C. magnifica) are recognized, the former from W. Himalayas, also known from Africa, while the latter two from W. S. China (Yunnan). However, in the past forty years the Chinese botanists have discovered 2 more species as new in N. W. Yunnan, thus bringing the total known species of the genus up to 5. The present paper is a brief summary on the genus Ceterachopsis, which will be published in detail in the Flora Sinica vol. 4. Pteridologists are also divided in their views regarding the generic status of Ceterachopsis with 5 well-defined species in Yunnan and the East Himalayas. We prefer to mintain it as a genus separate from Asplenium on account of its distinct morphological features. It is to be hoped that more species may come to light in the mountainsin N. W. Yunnan through further exploration now under way.