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1.
本文对我国种子植物特有属作了初步研究，提出如下几点粗浅的看法：
1．根据我国各特有属的现代地理分布格局，大部分特有属具有明显的温带性特点。
2．我国特有属在水平分布上具有极不均匀的特点。各特有属的广布程度都很低，生态特
化现象十分明显。在垂直分布上，则主要分布于中海拔地区。特有属数目并不随海拔增高而
增多。
3．根据特有属分布的密集程度和分布区边界的密集交叠情况，划定了三个特有属分布中 心，即川东—鄂西中心, 滇东南—桂西中心和川西—滇西北中心。前二中心可能是残遗中心，后一中心则可能为分化中心。 相似文献
2.
通过半个世纪以来对金佛山近2000号藓类植物标本的鉴定，现确定金佛山藓类植物有40科，133
属和245种(包括4亚种、9变种和1变型)。其区系成分以东亚成分为主(33．77％)，其次为温带成分
(28．57％)及热带、亚热带成分(24．68％)。文内还全面分析了金佛山藓类植物区系及我国南北8个山区藓
类植物区系之间的关系，用排序方法统计它们之间的相似性与非相似性系数，并着重就金佛山藓类植物区 系的过渡性特点作了探讨，提出在该山区与其邻近地区，存在一个苔藓植物东亚特有属的分布中心。 相似文献
3.
本文继续报道了薯蓣属(Dioscorea L.)块茎类5个组(sect． Combilium Pr．et Burk.，Sect. Lasiophyton Pr． et Burk.， Sect. Opsophyton Uline， Sect． Shannicorea Pr. et Burk.， Sect. Enantiophyllum Uline)23个种和变种的染色体数，并对一些分类群进行了讨论。它们都是基数为10的多倍体，是本属进化的类型。 根据染色体数的演化和二倍体种类的地理分布，我们推论我国横断山脉地区可能是薯蓣属的起源中心。 相似文献
4.
中国裸子植物分布区的研究(1)——松科植物的地理分布 总被引：3，自引：0，他引：3
应俊生 《中国科学院研究生院学报》1989,27(1):27-38
松科是裸子植物中最大的科，共有10属，约240种。我国有9属，约119种，其中2属
为我国特有属，67种为特有种。 本文概述了我国松科各属的水平分布和垂直分布规律；对各
属分布区进行了对比分析。除油杉属和松属外，其余各属的分布，既不深入到极为干旱的地
区，也不深入到热带山区。本文提出川西滇北地区是松科大部分属的发展中心，同时讨论了某
些属的分布区的退却变化。本文还认为，在目前该科化石资料不十分充足的条件下，要确定松 科及其各属的起源中心，可能性是不大的。 相似文献
5.
本文对我国苔草属二柱苔草亚属Subgen．Vignea作了系统排列，并提出以下几点的看法：
1．二柱苔草亚属是苔草属中比较自然的一个类群，我国有48种、7亚种和1变种，隶属于16个
组。根据Takhtajan的世界植物区划，将它们分成4种成分，即：(1)环北方植物地区成分，占总数的
20．4％；(2)东亚植物地区成分，占总数的55.5％。实际上，只有4个分类群出现于中国-喜马拉雅森
林植物亚区，而其余的都均分布于中国-日本森林植物亚区，并且在这一亚区内有8个特有成分，占特
有成分总数的61.5％；显然，中国二柱苔草亚属在中国-日本森林植物亚区内的分化较其他地区更为强
烈；(3)伊朗—吐兰植物地区成分，占总数的16.7％；(4)印度支那植物地区成分和印度植物地区成
分，占总数的7.4％。
2．高节苔草C．thomsonii和云雾苔草C．nubigena类群是Subgen．Vignea中较为原始的种类，
它们为印度支那植物地区和印度植物地区成分。这样非但Subgen．Indocarex原始类群分布于东南亚
和马来西亚，而Subgea．Vignea的原始类群也分布于东南亚，这也是对Nelmes提出Carex起源于印度-马来西亚地区的一个佐证。 相似文献
6.
本文结合地史初步探讨了第三纪以来武夷山苔藓植物可能发生的变化。武夷山的苔藓
植物主要为东亚区系成分和旧热带区系成分，与泛北极区系成分的相似性也相当明显。东亚
特有属(5个)系组成武夷山苔藓植物区系的重要因素之一，它低于黄山和西天目山的9个和
7个，与黄山等组成一个共同的苔藓植物东亚特有属的分布中心。从各方面的分析推测，这 类植物可能起源于第三纪，系一类“孑遗植物”。 相似文献
7.
本文对蓝钟花属Cyananthus及整个狭义的桔梗科Campanulaceae(s．str.)的花粉、
染色体和形态性状作了深入的系统研究，表明蓝钟花属是该科的最原始类群，它的亲缘属有党
参属Codonopsis和细钟花属Leptocodon。 对蓝钟花属中各个种及它的亲缘属的地理分布分
析，揭示了该属是典型的中国-喜马拉雅区系的成分，横断山地区是该属的频度和多样性中心；
认为中国西南部及其邻近地区至少是桔梗科原始属的保留中心，甚至可能是该科的起源中心。
作者最后对蓝钟花属各个种的性状作了生物统计分析，在此基础上对全属进行了全面的分类
修订，把原有的26个种9个变种归并为19种(包括2亚种)；对该属的次级分类也作了修订。
首次报道了该属的染色体数目和细钟花属的花粉形态。 相似文献
8.
朗楷永 《中国科学院研究生院学报》1990,28(5):356-371
兰科在横断山地区是维管束植物中的大科之一，共有91属，363种及9变种。 4属为我国特有属，其中1属为本地区所特有；155种及9变种为我国特有种。 其中69种及5变种为本地区所 特有。本文对属、种进行了分析，并对全部种的分布格局作了详细的介绍，概述了本地区兰科植物的区系组成及特点。本文从兰科植物属、种的分布提出了四川峨眉山是东亚植物区中划分中国-喜马拉雅植物亚区和中国-日本植物亚区的分界线上的一个重要的点的看法。 相似文献
9.
本文讨论了西藏波密古乡地区的主要植物群落及其垂直分布。
1．根据小带间植物种类相似系数情况，将波密古乡地区南、北坡划成八个植物垂直带
(图1)。
2．描述了七个不同性质的植物群落。各群落分布与水热条件之间的相互关系如图2所
示。 3．由于不同水热条件的影响，各植被带间在植物种数上的差异是比较显著的(表3)。 相似文献
10.
卢宝荣 《中国科学院研究生院学报》2002,40(6):539-545
披碱草属Elymus L．是小麦族Triticeae Dumort．中最大的属，全世界共有150多个种，广泛分布于
温带地区。我国约有80余种(包括鹅观草属Roegneria C．Koch)，是披碱草属的重要分布区和多样性分
化中心。由于披碱草属植物种类繁多、分布广泛、生境多样以及形态变异较为复杂，导致该属在分类上
存在许多问题。同时，由于地域的局限和地区间交流的缺乏，致使同一种披碱草属植物被不同的学者多
次发表及同物异名现象的出现。本文对E．antiquus和E．burchan-buddae这两个曾多次被订名的披碱草 属物种进行了分类订正。 相似文献
11.
鄂西神农架地区的植被和植物区系 总被引：1，自引：0，他引：1
Shennungia is generally known as “The highest mountain in Central China”. It is
situated at latitude 31°342'N., longitude 110°35'E. in western Hupeh.
The area explored is deeply cut in all sides by five V-shaped valleys, giving the
landscape a steep topography. Its summit is about 3105 meters above the sea level, and
the relative altitude is from 1000-2000 meters.
The climate of the region is warm temperate. The differences of humidity-warmth
condition between the eastern and the western flanks are quite marked.
In western Hupeh and the adjacent area of Szechuan the rugged topography still
preserves some tracts of natural forests at higher elevations. Our vegetational survey
is confined to localities above 1500 meters. The collection of plant samples of the flora
is extended to the whole mountain from the foothill to the peak. The present article
deals with only a part of the results of our survey.
1. The vertical vegetation belts of Mt. Shennungia and relationships with other
regions: The vegetation belts on the eastern and the western flanks of the mountain
are shown in diagram 2 and 3. The comparison of the vertical vegetation zones of the
Mt. Shennungia with those of the Yülungshan in N. W. Yunnan and the eastern
Himalaya to the west and with those of Hwangshan and Central Japan to the east
is shown in table 4, It shows that the plant communities of the Mt. Shennungia are of
temperate nature, and they are more closely related to those of Hwangshan in S.
Anhwei and of Central Japan than to the eastern Himalaya.
2. Floristic composition: The generic ranges of flowering plant are relatively
distinct and stable. Various distributional patterns of genera are analysized.
1) Statistics of the genera in various distributional patterns: The total number
of genera of flowering plants in this region are 762, belonging to the following four
categories. A) tropical genera 239 (31.3%), B) temperate genera 416 (54.7%), C)
endemic genera 47 (6%), and D) comsmopolitan genera 61 (8%).
2) Endemic genera: An examination of the composition of the flora in western
Hupeh reveals that 47 endemic Chinese genera occur in this mountain of which 24 are
monotypic genera, 20 oligotypic and 2 multitypic as shown in Table 4. The arborescent
genera are nearly all deciduous. They are of temperate nature.
3) Temperate genera: There are 416 genera in wastern Hupeh. They are
subdivides into the following three groups according to their distributional patterns:
A) The north temperate genera: There are 159 genera belonging to 62 families in
western Hupeh. B) Eastern Asian genera: There are 117 genera belonging to 69
families in western Hupeh. Among them 22 are common to the western Szechuan,
adjacent regions of Yunnan and the Eastern Himalaya. The remaining 95 genera are
commom to both eastern China and Japan. C) The Eastern Asian-eastern North-
American genera: Of the total 762 genera known in western Hupeh, 64 are disjunc-
tively distributed in both eastern Asia and eastern North-America.
4) The tropical genera: Of the 762 genera of the flowering plant of western
Hupeh, 239 (31%) are of tropical nature.
Finally, our survey shows: 1. Many of the primitive temperate genera and ende-
mic relicts concentrate in western Hupeh and the adjacent region of Szechuan indica-
ting that it might be one of refuges of tertiary flora. Moreover, it might also be one
of the most important regions of differentiation, development and distribution of tem-
perature flora. 2. The vegetation of this region is not only of temperate nature, but
also of a transitional nature. 3. According to an analysis of the flora and a compari-
son of the vertical distribution of the vegetation of Yülungshan and Eastern Himalaya
to the west with Hwangshan and Central Japan to the east, the floristic affinity of
western Hupeh is more closely related to eastern China and Central Japan rather than
to the Eastern Himalaya, and phytogeographically this region is intermediate between
the Sino-Himalayan and the Sino-Japanese patterns. However, the problem of phyto-
geography of western Hupeh and the adjacent region of Szechuan is a complicated
one requiring further study.
相似文献
12.
郝日明 《中国科学院研究生院学报》1997,35(6):500-510
中国种子植物特有属是局限分布于中国行政区域范围内的植物成分，就其分布特点看，集中分布于中国南部亚热带广阔区域。由于中国地域广袤，虽然大多数特有属分布在东亚自然地域范围内，但南部特有属的分布范围已进入古热带植物区的马来亚森林植物亚区的北部，而西部的特有属的分布范围已进入青藏高原地区。局限于不同地域分布的特有属，各自的起源发生、所经历的地质历史过程存在一定差别。本文以自然地理区划作为研究中国种子植物特有属分布区类型的依据，将中国特有属分布区类型划分为中国东部和中部特有分布变型、中国南部特有分布变型、中国西部特有分布变型和中国北部特有分布变型4类。其中中国南部特有分布变型所含特有属为热带区系成分，其它3个特有分布变型所含特有属为温带区系成分。这样能较客观地反映中国特有属的自然地理特征，有利于研究局部地区植物区系的地质历史演变过程。 相似文献
13.
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. 相似文献
14.
In the south-east and south Xizang, in cluding Medog, Zayü some western separate
valleys Yadong, Kama near Zentang in Dinggye, Boqu near Zham in Nyalam and
Gyirong, a mild climate prevails because of the very high mountains and the very deep
valleys. According to our preliminary survey, 4/5 of the genera and 7/10 of the
species, i.e. approximately representing all families and genera of the tropical and
subtropical bryofliora of Xizang, are restricted to these localities below the altitude of
2,300 meters. It almost agrees with the previous presumption that the Tsangpo gorge
is the line of connection between two paleoeontinents—Laurasia and Gondwana.
Moreover, the bryoflora of these localities, besides the Indo-Malasian elements and
East Asian elements as the main components, has at least about 40 genera in common
with south America, Australia and Africa. According to the historical phytogeogra-
phical point of view, the distribution range of centain genera is formed through a
period of long historical development. The same is true for the area of different
species, although they are found in widely separate areas right now, yet they might
have once a continuous distribution in certain historical age. The Indian plate collided
against the eastern part of Laurasia and afterwards the Australasian plate moved to
the north. All these might have dispersed the Gondwana elements as far as to the
southeastern part of Xizang.
It is very interesting to note that of the 32 genera of bryophytes endemic to East
Asia, 13 have recently been found in the southeast and south Xizang and also in the
neighbouring regions, i.e. Yunnan, Sichuan, where there are many genera being in
common with southeast and south Xizang and also highly concentrated in distribution.
This may suggest that the Himalayas, being the highest and youngest mountain range,
have changed the atmospheric circulation, and have created a new ecological condition
between tropical and frigid zones, which have given the distribution of the newly form-
ed genera a suitable circumstance to survive. It may be presumed that the region
covering counties Medog, Zayü, Yadong etc. in southeastern and southern parts of the
Himalayas is a new center of distribution of bryophytes under the influence of the up-heaval of the Himalayas. 相似文献
15.
Xizang (Tibet) is rich in Leguminosae flora, comprising 41 genera and 254 species
so far known, exclusive of the commonly cultivated taxa (including 11 genera and 16
species). There are 4 endemic genera (with 8 species), 10 temperate genera (with 175
species) and 19 tropical genera (with 46 species) as well as the representatives of those
genera whose distribution centers are in East Asia-North America, Mediterranean
and Central Asia.
1. There are altogether 4 endemic genera of Leguminosae in this region. Accord-
ing to their morphological characters, systematic position and geographical distribution,
it would appear that Salweenia and Piptanthus are Tertiary paleo-endemics, while
Straceya and Cochlianths are neo-endemics. Salweenia and Piptanthus may be some
of more primitive members in the subfamily Papilionasae and their allies are largely
distributed in the southern Hemisphere. The other two genera might have been derived
from the northern temperate genus Hedysarum and the East Asian-North American
genus Apios respectively, because of their morphological resemblance. They probably
came into existanc during the uplifting of the Himalayas.
2. An analysis of temperate genera
There are twelve temperate genera of Leguminosae in the region, of which the
more important elements in composition of flora, is Astragalus, Oxytropis and Cara-
gana.
Astragalus is a cosmopolitan genus comprising 2000 species, with its center
distribution in Central Asia. 250 species, are from China so far known, in alpine zone of
Southwest and Northwest, with 70 species extending farther to the Himalayas and
Xizang Plateau.
Among them, there are 7 species (10%) common to Central Asia, 12 species (15.7%)
to Southwest China and 40 species (60%) are endemic, it indicates that the differentia-
tion of the species of the genus in the region is very active, especially in the subgenus
Pogonophace with beards in stigma. 27 species amounting to 78.5% of the total species of
the subgenus, are distributed in this region. The species in the region mainly occur in
alpine zone between altitude of 3500—300 m. above sea-level. They have developed into
a member of representative of arid and cold alpine regions.
The endemic species of Astragalus in Xizang might be formed by specialization of
the alien and native elements. It will be proved by a series of horizontal and vertical vicarism of endemic species. For example, Astragalus bomiensis and A. englerianus are
horizontal and vertical vicarism species, the former being distributed in southeast part
of Xizang and the latter in Yunnan; also A. arnoldii and A. chomutovii, the former
being an endemic on Xizang Plateau and latter in Central Asia.
The genus Oxytropis comprises 300 species which are mainly distributed in the
north temperate zone. About 100 species are from China so far known, with 40 species
extending to Himalayas and Xizang Plateau. The distribution, formation and differ-
entiation of the genus in this region are resembled to Astragalus. These two genera are
usually growing together, composing the main accompanying elements of alpine mea-
dow and steppe.
Caragana is an endemic genus in Eurasian temperate zone and one of constructive
elements of alpine bush-wood. About 100 species are from China, with 16 species in Xi-
zang. According to the elements of composition, 4 species are common to Inner Mon-
golia and Kausu, 4 species to Southwest of China, the others are endemic. This not only
indicates that the species of Caragana in Xizang is closely related to those species of
above mentioned regions, but the differentiation of the genus in the region is obviously
effected by the uplifting of Himalayas, thus leading to the formations of endemic species
reaching up to 50%.
3. An Analysis of Tropical Genera
There are 19 tropical genera in the region. They concentrate in southeast of Xizang
and southern flank of the Himalayas. All of them but Indigofera and Desmodium are
represented by a few species, especially the endemic species. Thus, it can be seen that
they are less differentiated than the temperate genera.
However, the genus Desmodium which extends from tropical southeast and northeast
Asia to Mexio is more active in differentiation than the other genera. According to Oha-
Shi,s system about the genus in 1973, the species of Desmodium distributed in Sino-Hima-
laya region mostly belong to the subgenus Dollinera and subgenus Podocarpium. The
subgenus Dollinera concentrates in both Sino-Himalaya region and Indo-China with 14
species, of which 7 species are endemic in Sino-Himalaya. They are closely related to
species of Indo-China, southern Yunnan and Assam and shows tha tthey have close con-
nections in origin and that the former might be derived from the latter.
Another subgenus extending from subtropical to temperate zone is Podocarpium.
Five out of the total eight species belonging to the subgenus are distributed in Sino-
Himalaya and three of them are endemic.
An investigation on interspecific evolutionary relationship and geographic distribu-
tion of the subgenus shows that the primary center of differentiation of Podocarpium
is in the Sino-Himalaya region.
Finally, our survey shows that owing to the uplifting of the Himalayas which has
brought about complicated geographic and climatic situations, the favorable conditions
have been provided not only for the formation of the species but also for the genus in cer-tain degree. 相似文献
16.
中国种子植物特有属的数量分析 总被引：3，自引：0，他引：3
王荷生 《中国科学院研究生院学报》1985,23(4):241-258
Chinese flora with many endemic elements is highly important in the world’s
flora. According to recent statistics there are about 196 genera of spermatophytes, be-
ing 6.5% of total Chinese genera. These endemic genera comprising 377 species belong
to 68 families, among which the Gesneriaceae (28 genera), Umbelliferae (13), Compo-
sitae (13), Orchidaceae (12) and Labiatae (10) are predominant. The tropical type
containing 24 families and 80 genera is dominant. After it follows the temperate type
with 23 families and 50 genera. There are also 4 families endemic to China, i.e. Gin-
kgoaceae, Bretschneideraceae, Eucommiaceae and Davidiaceae. It shows that genera
endemic to China are obviously related to the tropical and temperate flora in essence.
The endemic monotypic genera (139) and endemic obligotypic genera (48) combin-
ed make up more than 95% of the total number of genera endemic to China. Phylo-
genetically more than half of them are ancient or primitive. The life forms of all ende-
mic genera are also diverse. Herbs, especially perennial herbs, prevail with the propor-
tion of about 62%, and trees and shrubs are the next, with 33%, and the rest are lianas.
Based upon the calculated number of genera endemic to China in each province and
the similarity coefficents between any two provinces, some conclusions may be drawn
as follows:
Yunnan and Sichuan Provinces combined are the distribution centre of genera en-
demic to China and may be their original or differentiation area, because numerous
endemic genera, including various groups, exist in these two provinces. The second is
Guizhou where there are 62 endemic genera. Others form a declining order, south
China, central China and east China. But towards the north China endemic genera de-
crease gradually, and the Qinling Range is an important distributional limit.
The largest simitarity coefficient, over 50%, appears between Shaanxi and Gansu
probably because of the Qinling Range linking these two provinces. But between any
other two provinces it is less than 30% and it is generaly larger between two south pro-
vinces than between two north provinces.
These characteristics mentioned above are correlated with topography and climate,
and they may be resulted from the diversification in geography and climatic influence
for a long time. 相似文献
17.
木兰科分类系统的初步研究 总被引：10，自引：0，他引：10
刘玉壶 《中国科学院研究生院学报》1984,22(2):89-109
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. 相似文献
18.
太白山位居秦岭的中段，为秦岭山脉第一高峰。该山区是我国温带植物区系最丰富的地区之一，
约有种子植物1782种，隶属于125科，657属，包括热带属130属，温带属436属和特有属24属。该地
区20个较大科的种数，约占其全部植物区系的66.6％，其中特有种653种。本文对这些大科的性质及
其在植物区系和植被中的作用进行了分析讨论。在分析了全部属和植物群落优势种的地理分布的基础
上，着重讨论了该地区与其他九个山区的植物区系关系。
本文对植被垂直带划分；主要植物群落的基本特点和区系相似性；物种多样性与海拔高度变化的关
系以及生活型谱与不同坡向和海拔变化的关系等作了具体分析。对该地区主要植物群落的形成时期以
及对秦岭地区植物区系的过渡性质提出了自己的看法。从植物学角度出发，秦岭地区作为亚热带和温带
植物的分界线的提法与该地区的植物区系和植物群落性质以及水热条件情况不相符合 相似文献