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1.
为探讨獐牙菜亚族(subtribe Swertiinae)各属之间和一些属内的系统关系,本研究选取了该亚族14属68种1变种,采用最大简约法(maximum parsimony)和贝叶斯法(Bayesian inference)对样品核基因ITS和叶绿体基因matK的两个片段进行独立和联合分析。结果显示:Bartonia位于亚族的最基部;喉毛花属(Comastoma)、肋柱花属(Lomatogonium)和假龙胆属(Gentianella)都非单系,处于同一个较为进化的分支中;獐牙菜属折皱组(Swertia sect. Rugosa)和獐牙菜组(S. sect. Swertia)亲缘关系最近,宽丝组(S. sect. Platynema)和藏獐牙菜组(S. sect. Kingdon Wardia)亲缘关系最近;口药花属(Jaeschkea)与獐牙菜属多枝组(S. sect. Ophelia)的大籽獐牙菜(Smacrosperma)亲缘关系最近。同时讨论了獐牙菜亚族形态分类与分子数据不一致的原因。  相似文献   

2.
论世界蒿属植物区系   总被引:15,自引:2,他引:13  
林有润 《植物研究》1995,15(1):1-37
本文从多学科, 包括形态、地理分布、孢粉、古植物、谱系分支分析及化学成分等学科的研究, 论述了世界蒿属植物的系统分类及其种属地理、历史地理和区系地理.  相似文献   

3.
The genus Dichocarpum was established by W. T. Wang and Hsiao in 1964, who divided the genus into 2 sections: Sect. Dichocarpum including 10 species distributed on the mainland of E. Asia, and Sect. Hutchinsonia including 9 species native to Japan. M. Tamura and L. A. Lauener made a revision of the genus in 1968, who divided the genus into 4 sections, three for the species of the mainland of E. Asia, including 3 series and 10 species, and the other for the species of Japan, including 2 subsections, 3 series and 9 species. In the present paper, the genus is divided into 2 sections and 6 series, including 15 species and 3 varieties, and a putative phylogeny of the genus is proposed. The genus may be close to the genus Asteropyrum, and these two genera are rather specialized in Thalictroides (Ranunculaceae), because they have three very similar characters: the petal with a long claw, the stephanocolpate pollen and the chromosome morphology. The genus has 2n=24, 35(36?), which indicates that its basic number is X=6, and the species on the mainland of E. Asia (Sect. Dichocarpum) may well be paleotetraploids, whereas those in Japan (sect. Hutchinsonia) are paleohexaploids. Most of the advanced species are distributed in Japan and the most primitive ones in China and the Himalayas, the distribution pattern seggests that the Japanese members of this genus might have immigrated from China in the Tertiary, and differentiated and evolved there. The putative phylogeny of the genus is shown in Fig. 2 (at series level)  相似文献   

4.
獐牙菜亚族(subtribe Swertiinae)是龙胆科(Gentianaceae)中分类处理较困难的一个亚族。为探讨该亚族各属之间和属内的系统关系,选取了该亚族86种及变种,采用ML和BI方法对样本的叶绿体基因mat K和rbc L片段进行分析,构建了该亚族的系统发育树,用马尔科夫蒙特卡洛算法(MCMC)的分子序列贝叶斯分析推算了该亚族的关键演化时间点。结果显示:①龙胆亚族和獐牙菜亚族各自为单系,且互为姐妹类群;②獐牙菜属、假龙胆属、肋柱花属和喉毛花属均不是单系群,各属的种在系统发育树上互有交叉,特别是獐牙菜属的多个种分别聚到不同的支上,与其它属是并系关系;③獐牙菜亚族49个种在约4 Ma开始形成;④分子数据支持何廷农分类系统对于獐牙菜亚属和多枝亚属的属间划分,部分支持多枝亚属下多枝组和宽丝组的划分;⑤异型花属、獐牙菜属、假龙胆属、喉毛花和肋柱花属的属间分类以及獐牙菜属肉根亚属密花组的系统位置仍需进一步讨论。  相似文献   

5.
The genus Ligularia Cass. is one of the large genera in Compositae-SenecioneaeTussilagininae. In subtrib. Tussilaginae, Ligularia is closely related to, but more advanced than, the genus Farfugium Lindl. It includes six sections, 11 series and 129 species. All the taxa are distributed in Asia with only two species extending to Europe. There are 119 species in E. Asia, Comprising 96 % of the world total. The highest concentration of species in E. Asia occurs in the Hengduan Mountains. In this area there are four section, six series and 67 species, of which 61 species are local endemics; thus 66% of sections, 54.5% of series and about 52 % of species in the world occur in this small area, indicating that it is a major distribution centre for Ligularia. According to character analysis, sect. Corymbosae ser. Calthifoliae with 5 species was considered as the most primitive group in this genus, which has reniform leaves, palmate veins, a few large capitula (arranging in Corymb-like inflorescence), and semispherical involucre etc. The primitive species, L. dentata and L. hodgsonii, are distributed from E. Sichuan to Japan via Hubei, Hunnan, Anhui, Fujian. This distribution pattern is consistent with that of its allied genus, Farfugium. According to the principle of common origin, the ancestors of the two genera appeared most probably in the same area. It was inferred that the area from E. Sichuan of China to Japan was the original area of the genus Ligularia, However, on the basis of geological history and the modern distribution of this genus, the author considers that central China with E. Sichuan might be the primary original area of Ligularia. Its dispersal route was mainly along the mountains of southern margin of Asia, with relatively few members dispersed northea stwards to NE. Asia. The origi-nal time of the genus Ligularia was at least not later than the middle Cretaceous.  相似文献   

6.
橐吾属的起源、演化与地理分布   总被引:20,自引:1,他引:19  
橐吾属Ligularia Cass.是菊科千里光族款冬亚族的一个大属。在款冬亚族中本属与大吾风草属 Farfugium Lindl.亲缘关系最近,但进化程度较高。本属包括6组,11系129种。所有种类均分布在 亚洲,仅2种扩散至欧洲。在东亚地区有119种,占该属总种数的96%。高度集中在横断山区的有4组、 6系67种,其中61种为特有种,占该属总组数的66%,总系数的54.5%,总种数的52%。这个事实 表明了横断山区是该属的多度中心和多样化中心。通过性状分析,伞房组伞房系Sect.Corymbosae, Ser.Calthifoliae叶肾形,具掌状叶脉,头状花序大而少,排列呈伞房状,总苞半球形,被认为是该属的 原始类群。原始种齿叶橐吾L. dentata和鹿蹄橐吾L.hodgsonii的分布区从我国四川东部经过湖北、湖 南、安徽、福建等省至日本。这个分布格局与近缘属大吴风草属Farfugium一致。 根据共同起源原理,这两个属的祖先极有可能就发生在这一地区。因此我们推测东亚地区从中国四 川东部至日本这一地区是本属的发源地,然而根据地质历史和现代分布,作者认为中国中部(包括四川 东部)是本属的初始起源地。该属起源后,基本上沿亚洲南缘的山地扩散,少数种类向东北至亚洲东北部。本属起源时间至少不晚于中白垩纪。  相似文献   

7.
西南獐牙菜的胚胎学及其系统学意义   总被引:5,自引:0,他引:5  
报道了西南獐牙菜的大、小孢子发生及雌,雄配子体发育过程,并以此讨论了獐牙菜属宽丝组和多枝组的分类等级和系统演化关系,西南獐牙菜花药四室;药壁发育为双子叶型;绒毡层二型起源,腺质型;中层细胞2层;药室内壁纤维状加厚,药壁表皮宿存,小孢子母细胞减数分裂为同时型;小孢子四分体的排列为四面体形,成熟花粉为3-细胞型,孔子房为3心皮,1室,胚珠12列,故为超侧膜胎座,薄珠心,单珠被,倒弯生胚珠,大孢子母细胞减数分裂形成4个大孢子呈直线形排列,合点端的大孢子具功能,胚囊发育为蓼型,两极核在受精前融合为次生核,3个反足细胞次生增殖为5-8个,宿存,比较宽丝组和多枝组的胚胎党性一状表明宽丝组从多枝组中分出是合理的,在系统位置上宽丝组较多枝组进化。  相似文献   

8.
In this paper the classification of the genus Bergenia Moench is provided, its geographic distribution analysed, and the phylogeny also traced. Based on an analysis of morphological characters such as leaves, ocreas, branches of inflorescences, Pedicels, hypanthium, sepals, and glandular indumentum, thi genus is divided into 3 sections: 1. Sect. Scopulosae J. T. Pan, sect. nov., 2. Sect. Bergnia, 3. Sect. Ciliatae (A. Boriss.) J. T. Pan, stat. nov. The Sect. Scopulosae J. T. Pan may be considered as the primitive one, while Sect. Ciliatae (A. Boriss.) J. T. Pan may be regarded as the advanced one, with Sect. Bergenia in between. So far, the genus Bergenia Moench comprises 9 species in the total. Southeast Asia and North Asia (south and east Siberia, USSR) each have only 1 species, West Asia (Afghanistan) has 2, Central Asia (Kirghizia-Tajikistan-Uzbekstan area, USSR) 3, South Asia 4 (Nepal has 4, India, Pakistan and Kashmir area each has 3, Bhutan and Sikkim each has 2), East Asia 6. In East Asia, Mongolia and Korea each have only 1 species, but China has 6 (including endemic species 2 and new species 1). Sichuan Province and Xizang Autonomous Region each have 3, Yunnan Province 2, Shaanxi Province (Qinling Mountains) and Uygur Autonomous Region of Xinjiang each have only 1. Thus the distribution centre of this genus should be in the region covering Sichuan, Yunnan and Xizang. Moreover, it is noteworthy that Bergenia scopulosa T. P. Wang in Sect. Scopulosae seems to have retained primitive characters, for example, non-ciliate leaves and ocreas, glabrous pedicels, hypanthium and sepals, and this primitive species is found in Qinling Mountains and Sichuan. According to the distribution of the primitive species, the author suggests that the centre of origin of this genus be in the region covering Qinling Mountains and Sichuan.  相似文献   

9.
The genus Calligonum L. includes a total number of 35 species in the world, of which 24 are in China. They are grouped into four sections, of which Sect. Calliphysae (Fisch. et Mey.) Borszcz. is the most primitive and Sect. Medusae Sosk. et Alexender. is the most progressive. The Calligonum L. is an ancient genus in the arid desert flora, and central Asia is the place of its origin. Some species migrated to the Middle Asia and Iran, developing into a second center there. Also, some newly occurred species of the Middle Asia emigrated eastwards to central Asia, so the genus Calligonum L. in China comprises components of both central Asia and the Middle Asia. The genus Calligonum L. is distributed in North Africa, south Europa and Asia, and China is the eastmost part of the distribution range. They grow in Nei Monggol, Gansu, Qinghai and Xinjiang. There are 12 species in the Zhuengar Basin, covering 50 percent of the total number of species in China, amd thus the genus is the most abundant there.  相似文献   

10.
椴树属的地理分布   总被引:13,自引:0,他引:13  
椴树属Tilia是椴树科一个形态特殊且唯一的北温带分布属,分布于亚洲、欧洲和北美,构成典型的北温带分布格局,三个分离的分布区之间缺乏共有种。本文对各分布区的种类进行重新评价,确认全属25种。其中东亚17种,占68%,包含了现存种类各个演化阶段的类群,是现代分布中心;欧洲-西西伯利亚6种,属于木果组及壳果组;北美2种,均为木果组成员。化石分布与现代地理分布格局基本相似,但分布纬度较现代分布偏北,达到北纬80°附近,且还出现于现今无椴树分布的亚洲大陆腹地,北美西部椴树至第三纪末完全绝迹,而东部到第四纪才有化石记录。根据现代地理分布,结合化石证据、地质历史、气候变迁及形态演化推测,椴树属可能在白垩纪晚期起源于中国东部亚热带山地,至少到始新世之前已散布至欧洲和北美西部。渐新世之后的全球降温和更新世大冰期对椴树属现代地理分布格局的形成起着至关重要的作用。  相似文献   

11.
The present paper deals with the infrageneric classification, phylogeny and geographic distribution of the genus Lomatogonium. A cladistic analysis was undertaken to establish the taxa and to evaluate the relationships between the taxa. The PAUP computer program was used in this analysis. The most parsimonious tree (Cladogram) of the rotate-corolla group of subtribe Gentianinae shows that Lomatogonium is closely related to Lomatogoniopsis and Swertia, but distantly to Veratrilla. Among them, Swertia is more primitive than Lomatogonium and hence Sect. Swertia was selected as the outgroup to polarize the character states of ingroup (Lomatogonium). A data matrix of 29 charaters of Lomatogonium was made for constructing the cladogram. Two most parsimonious trees were formed one of which, with the lowest f value, was at last selected as a shortest tree. In this tree 18 species fall into three groups, i.e. Sect. Sarcorhizoma, Sect. Lomatogonium and Sect. Pleurogynella. The former comes at a lower level with more plesiomorphies while the latter at a higher level with more apomorphies. Lomatogonium is distributed in the northern temperate zone. However, 16 species are centred in Asia and two extend to Europe, or further to the Arctic region, but none has been found from Africa, Australia and South erica. The analysis of distribution pattern of species shows that the Qinling-Hengduan Mountain region is both the frequence and diversity centers of Lomatogonium. From the cladogram of Lomatogonium (Fig. 5 ), L. perenne appears to occupy the most plesiomorphic node. This is an indication that it is the extant species closest to the ancestral form and it also implies that the ancestral species may reside in the habitat of this species (the Qinlin-Hengduan Mountain region). On the other hand, a umber of species of Swertia Sect. Swertia also occur in this region today, which indicates that the Qinlin-Hengduan Mountain region may well be the original center of Lomatogonium. From the distribution pattern of L. rotatum, it can be concluded that the time of the origin dates back at least before the Pliocene. After emergence, this genus had first developed and dispersed in the original center and adjacent region, then diverged into two lineages. One gave rise to the widespread species (northern temperate distribution species L. carinthiacum and L. rotatum), and the other formed the Himalayan species.A taxonomic revision of the whole genus Lomatogonium is presented. In this paper, one new section (Sect. Sarcorhizoma), one new species (L. zhongdianense S. W. Liu et T. N. Ho) and one new variety (L. forrestii var. densiflorum S. W. Liu et T. N. Ho) are described. The key to the species is given. Type studies are made for all the taxa.  相似文献   

12.
杨亚科(Populoideae)植物自然分布于热带非洲和大约从北纬19°~70°度的北半球,由胡杨属(Balsamiflua)和杨属(Populus)2个属所组成。胡杨属间断分布于赤道非洲、古地中海地区和墨西哥,包含2个组(胡杨组、墨杨组)和约3个天然种。杨属分布于欧洲、亚洲、非洲(北缘)和北美洲的广大地区,包含大叶杨亚属(Subgen.Leucoides)(大叶杨组)、杨亚属(Subgen.Populus)(青杨组、黑杨组、杨组)2个亚属和约52个天然种。拟定了杨亚科属的检索表、胡杨属组和种的检索表、杨属亚属和组的检索表以及杨属中各组种的检索表。提供了一个杨树种类目录,包括它们的正名、异名、文献引注和地理分布等。  相似文献   

13.
中国栎属的起源演化及其扩散   总被引:42,自引:4,他引:38  
  相似文献   

14.
杨亚科(Populoideae)植物自然分布于热带非洲和大约从北纬19°~70°度的北半球,由胡杨属(Balsamiflua)和杨属(Populus)2个属所组成。胡杨属间断分布于赤道非洲、古地中海地区和墨西哥,包含2个组(胡杨组、墨杨组)和约3个天然种。杨属分布于欧洲、亚洲、非洲(北缘)和北美洲的广大地区,包含大叶杨亚属(Subgen.Leucoides)(大叶杨组)、杨亚属(Subgen.Populus)(青杨组、黑杨组、杨组)2个亚属和约52个天然种。拟定了杨亚科属的检索表、胡杨属组和种的检索表、杨属亚属和组的检索表以及杨属中各组种的检索表。提供了一个杨树种类目录,包括它们的正名、异名、文献引注和地理分布等。  相似文献   

15.
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 axillary 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, druplets adhering to the receptacles and with high chromosome numbers (2n = 56). Basing upon the evolutionary tendency of morphological features, chromosome numbers 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 important 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 southwestern parts of China, namely Yunnan, Sichuan and Guizhou (tab. 3. 4.). It is interesting to note that the centre of distribution of Rubus in China ranges From northwestern 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 distribution and differentiation of Rubus in China, but it may also be the center of origin ofthis genus.  相似文献   

16.
Discussed in the present paper are evolutionary trends of important morphological characters of Deutzia, systematic position of several closely related genera, geographical distribution and characteristics of floristic elements. Finally the classificatory revison of the genus is made and a key to species is given. As a result, evolutionary trends of the important morphological characters in Deutzia are suggested; petals from imbricate to valvate, stamens from indefinite to definite, filaments from edentate to dentate, ovary from half-inferior to inferior. Therefore, the section Neodeutzia with valvate corolla and infinite stamens with edentate filaments should be included in this genus. The sections Neodeutzia and Mesodeutizia seem to be better considered as primitive taxa, while the section Deutzia advanced one. There are 52 species of Deutzia in China , which are grouped into two sections ( Sect. Mesodeutzia, Sect. Deutzia), four subsections (Subsect. Deutzia, Subsect. Grandiflorae, Subsect. Stenosepalae, Subsect. Cymosae)and 17 series. Sixty- five species are so far recognised in the genus Deutzia. They are mainly distributed in E. Asia and disjunctively in N. America. China is therefore an area the richest in species of Deutzia in the world, making up 80% of the total species of this genus. The greatest concentration area is in Sichuan (23 species), Yunnan (21 species), Hubei (12 species) and Shanxi (10 species), this is boundary area between Sino-Himalayan subregion and Sino-Japanese subregion, where occur abundant species (including 39 endemic species) and diverse taxa (2 section and 4 subsection). Based on these facts it is proposed that the present center of distribution and differentiation of Deutzia be in the southern part of the Hengduan Mountains, the Qingling Range and C. China.  相似文献   

17.
The present paper deals with the history of taxonomy, groos morphology, pollen morphology, distribution, system and taxonomic treatment of the genus Polygala L. from China. Three subgenera, 4 sections, 41 species and 8 varieties are recognized in this treatment, of which 2 sections are described as new. The system of Chinese species of Polygala L. is proposed as follow: Subgen. 1. Chamaebuxus (DC.)Duchartre (Typus: Polygala chamaebuxus L.) Sect. 1. Arillus S. K. Chen, sect. nov. (Typus: Polygala arillata Buch.-Ham. ex D. Don). This section consists of about 20 species, distributed in the tropics and subtropics of Asia and Africa, with 7 species found in South China. Subgen. 2. Pseudosemeiocardium (Adema) J. Chetek et B. Krisa( Typus: Polygala furcata Royle). Sect. 1. Villososperma C. Y. Wu et S. K. Chen (Typus: Polygala wattersii Hance ). There are 3 species in this section, distributed in S. China and N. Vietnam. Sect. 2. Saxicola S. K. Chen, sect.nov. (Typus: Polygala saxicola Dunn). This section consists of 8 species, among which P. tricornis Gagnep. and P. saxicola Dunn are distributed in both Vietnam and China, and the other 6 species are endemic to China. Sect. 3. Pseudosemeiocardium ( Typus: Polygala furcata Royle). This section consists of about 7 species, distributed in SW China, extending from Indo-China Peninsula, southward to Malay, the Philippines, Indonesia and New Guinea, westward to the southern slope of the Himalayas and N. India, northward to Japan. Subgen. 3. Polygala (Typus: Polygala vulgaris L. ). 400 species or more belong to this cosmopolitan subgenus. Most species are found in America and Africa, with 18 species discovered in China. Taxonomic evidence: The characters of flowers, fruits and seeds, the indumentum of seeds and presence or absence of caruncles are stable and also correlated with one another. There is a certain combination of the above-mentioned characters in a given group, which provide reliable evidence for the infrageneric division. A good example is the Polygala arillata group, grown under the tropical and subtropical forests, which has large, yellow flowers, with sepals fallen after blossom. The flower has carinas with a cristate appendix, which is of 2-9 long narrow pieces. The seeds are spherical, with a hooded caruncle. Its fruits are of annuloid stripes. (Fig. 1). The Polygala tenuifolia Willd. group, cosmopolitan in distribution, has a middle-sized, purple or yellow flower with persistent sepals. Cristate appendix of carina is usually fimbricate. The seed in the group is oblong or subovoid, with a trilobate caruncle. Carpels of the fruits of this group are without annuloid stripes(Fig. 3). The third group, Polygala saxicola group, is between the two as indicated above. The group has a small, yellow or occasionally purplecolored flower, with sepals fallen after blossom or sometimes with a persistent outer sepal. The cristate appendix of carina is lamellar or cucullate. The seed of the group is sometimes with pubescences and hooded caruncles sometimes with hirtoselike villoses and no caruncle (Fig. 2) pollen morphology and systematic treatments: The pollen morphology of the domestic Polygala seems to support division of Polygala L. into three groups as follows: A. Pollen grains subspheroidal, 10-19-colpate, colpi usually rather wide, relatively psilate in the polar area; B. Pollen grains reniform, 22-26-colpate, sculptural in the polar area; C. Pollen grains long-spheroidal or subspheroidal, 9- 23-colpate, with long and deep colpi, which usually extend to the relatively psilate polar area. The pollen morphology is naturally correlated with the morphology of flowers, fruits and seeds. Based on these, three subgenera and four sections no subdivision in Subgen. Polygala)are recognized.  相似文献   

18.
This revision deals with the system, evolution, distribution, cytotaxonomy and taxonomic treatment of the genus Aristolochia Linn. from E. & S. Asia, which covers Japan, USSR (Far East), China, Viet Nam, Laos, Cambodia, Thailand, Burma, India, Bhutan, Nepal, Sikkim, Bangladesh and Pakistan. Total 2 subgenera, 7 sections, 4 series, 68 species and 1 variety (cultivated species not included) are recognized in this treatment, of which 3 sections and 2 species are described as new. In addition, 13 new synonyms and some new records to this region are also included. Ystem Having estimated all the works dealing with the subdivision of the genus by the previous authors, the system of O. C. Schmidt (1935) is chosen as the basis, with a change of the sequence of the subdivisions. The subgenus Pararistolochia (Hutch. & Dalz.) O. C. Schmidt, which has indefinite stamens and gynandrous lobes, seems to be better considered as the most primitive one in the genus, while the subgenus Siphisia (Raf.) Duch., which has definite stamens and gynandrous lobes, anthers arranged in 3 pairs and more modifications of the perianth, seems to be the most advanced one. The perianth of the subgenus Siphisia has differentiated into several types, and it is more rational using this character to classify sections than lobes of the gynostemium. In this way, three new sections has been established. A suggested system of the genus is summarized as follows: Subgen. 1. Pararistolochia (Hutch. & Dalz.) O. C. Schmidt Subgen. 2. Aristolochia: Sect. 1. Aristolochia (2 series), Sect. 2. Gymnolobus Duch. Subgen. 3. Siphisia (Raf.) Duch.: Sect. 3. Pentodon Klotz, Sect. 4. Odontosiphisia J. S. Ma, Sect. 5. Leptosiphisia J. S. Ma, Sect. 6. Nepenthesia Klotz., Sect. 7. Obliquosiphisia J. S. Ma, Sect. 8. Siphisia (2 series). Evolution According to the character analysis of the genera of Aristolochiaceae, the evolutionary trends of the family are proposed as follows: 1, the perianth from double to single, from cup-like to tubular, 2, stamens from indefinite to definite, from separate from pistil to united into a gynostemium with pistil, which is a major evolutionary line in the family, 3, ovary from half-superior to inferior, and 4, fruit from a follicle to a capsule. It is evident that the genus Aristolochia, with a tubular perianth, stamens 6, a gynostemium, an inferior ovary and a capsule, is in highly advanced position in the family. The subgenus Pararistolochia, which has more stamens and more lobes of gynostemium, is very similar to the genus Thottea Rottb. and thus better considered as the most primitive subgenus in the genus. The subgenus Siphisia, which has definite stamens (6) in 3 pairs and 6 lobes of gynostemium as well as the polyploid feature (2n=4x=28), is the most advanced subgenus. As a result of the character analysis, the evolutionary trends of the subgenera in the genus, which are in accordance with those of the family, are proposed as follows: 1. stamens from indefinite to definite, and 2. gynostemium lobes from more to less. Distribution The more primitive subgenus Pararistolochia is only distributed in West Africa (except 1 species in Malesia), the subgenus Aristolochia in the tropical and subtropical regions, rarely in the temperate one, and the most advanced subgenus Siphisia occurs mainly in E. Asia, occasionally in N. America. The result of this work shows that the Hengduan Mountains is the second center of distribution after South America. The second center of distribution is of following features: 1. complex composition of taxa, among 3 subgenera and 8 sections, 2 subgenera and 7 sections have been recorded here, 2. rich in species, more than half of the total E. & S. Asian species, i.e. about 42 species have been found in this region, and 3. numerous endemics, more than 85 percent of the total number of species in the region, i.e. about 35 species, are endemic. Cytotaxonomy and taxonomic treatment The known chromosome numbers in 43 species, with 34 reported by Gregory (1956) and Fedorov (1969), together with 9 species newly reported in this work, show that Subgen. Aristolochia with 2n=2x=14, rarely 12, is apparently more primitive than Subgen. Siphisia with 2n=2x=28.  相似文献   

19.
刘建国 《植物研究》1991,11(1):101-107
本文论述了猪毛菜属系统分类的简史。依据该属的系统分类新资料,对我国猪毛菜属的分组系统作了进一步整理,将国产猪毛菜属植物归为6组5亚组。文中还讨论了该属的起源发生、迁移、分化以及地理分布等问题。  相似文献   

20.
中国灯心草属植物的研究   总被引:8,自引:0,他引:8  
本文通过对国产灯心草属植物的研究,提出了一个中国灯心草属分类系统排列,首次确认我国产6亚属,14组(包括10个新组),4个系(包括3个新系),77种(包括14个新种),l亚种(新亚种)和10变种(包括4个新变种),对其中一些种类作了归并及处理。  相似文献   

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