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Two new species and one new variety of Salix L. from western China,
namcl. S. ludingensis T. Y. Ding et C. F. Fang, S. neoamnematchinensis T. Y.
Ding et C. F. Fang, and S. taoensis Gorz var. leiocarpa T. Y. Ding et C. F.Fang, are reported in this paper. 相似文献
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方振富 《中国科学院研究生院学报》1987,25(4):307-313
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. 相似文献
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青藏高原柳属植物的发生和分布 总被引：2，自引：0，他引：2
1. Uplifting of Qinghai-Xizang plateau has brought great influence on the origina-
tion and distribution of species inside the genus Salix. There are 91 sp. (incl. 2 cult.
sp.), 16 var. and 3 f. belonging to 15 Sect. in this region, among these species the en-
demics attain to 58 sp., 14 var. and 3 f. So it has become one of the most important
centres of distribution of Salix in the world. Species common with other regions attain
only to 32. Thus it is also clear that correlation between salicaceous flora in this re-
gion and that of other regions is not so much developed, and that the salicaceous flora
of Qinghai-Xizang plateau was mainly originated autochthonously during the upheaval
of plateau.
2. Along a demarcation line delineated from Gyirong through Lhasa and Qamdo to
Lanzhou, to the north-western region the total number of species of this genus is sum-
med up to 7 sp. and 1 var. (incl. 2 cult. sp.), and they distribute only in the West Hima-
laya and Pamir-Kunlun regions. Besides 2 cult. sp., there is only 1 endemic, and
others all should be migrants from Europe or West Asia. In the south-eastern part, be-
cause the climate is moister, the species of Salix may be summed up to 84 sp., 15 var.
and 3 f., among them 73 sp., 20 var. and 3 f. are endemics, accounting for 68 percent
of the total.
3. In East Himalaya and South Henduan Shan (southward of lat. 30°N.) there
are 78 sp., 12 var. and 4 f., among them 50 sp., 10 var. and 2 f. are endemics. They
represent the different stages of phylogenetic development of this genus. So here may
be the centre of origination and distribution of Salix species in the all Sino-Himalaya
flora. The common species between East Himalaya and South Henduan Shan regions
attain to 41. Because the latter forms a part of Sichuan and Yunnan plateau and the
former did not become a land until Quaternary Period, the plants of the former mainly
are the migrants from the latter.
4. The most characteristic group of Salix in this region is Sect. Lindleyanae
Schneid. with a total of 18 sp. and 1 var. This group adapting to the somewhat en-
vironment changes is quite different from Sect. Retusae A. Kern. in the Arctic and high
mountains of higher latitudes in many characters, so it should be originated autochto-
nously, and it is certainly not a migrant from Arctic. This Sect. seems to be developed
from Sect. Floccosae Hao and in turn from Sect. Sclerophyllae Schneid. and Sect. Den-
ticulatae Schneid. This developmental direction has assumed an important branch in the
phylogenetic development of the whole genus.
5. In addition, there are two interesting and important regions on the north-eastern
and eastern to Qinghai-Xizang Plateau, i. e. on the north-east Anymaqen Shan (Amne-
machin mountain) and on the east Qiong Lai Shan. There are many endemic species
pertaining to these two parts, among these species some may be ancient relicts since
Tertiary. It is to be expected that more additional scientific results will be obtainedafter some more extensive works done in these two regions. 相似文献
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