%0 Journal Article
%T Systematics of the Genus Cyananthus Wall. ex Royle
蓝钟花属的系统学研究
%A Hong De-Yuan
%A Ma Li-Ming
%A
洪德元
%A 马黎明
%J 中国科学院研究生院学报
%D 1991
%I
%X The genus Cyananthus is distributed in the Himalayan Floristic Subregion. In the early years, it was treated as a member of Polemoniaceae, but it is now generally regarded as a natural group of Campanulaceae. Made in this paper were a comprehensive comparative morphological study, a biometrical analysis of quantitative characters and an analysis of distri- bution pattern. The systematic position of the genus is discussed based on the evidence from pol- len morphology, chromosome number and external morphology. Finally the classification of the genus is revised. As a result of the character analysis, the evolutionary trends of the characters in Cam- panulaceae are suggested: superior ovary is a primitive state; the pollen grains have evolved from long-multicolpal to short-colpal, then to multiporate; the basic chromosome numbers have changed from 7 to 8 or 9, from which the groups with x=17 are derived (see Fig. 2), Fig. 2 illustrates that Cyananthus is the most primitive genus in the Gampanulaceae, closely related to Codonopsis, Platycodon, Leptocodon and Campanumoea. All these genera are rela- tively primitive in the family. The genus Cyananthus is distributed in S. E. Gansu (Zhugqu), W. Sichuan, S. and E. Xizang, S. Qinghai and N. W. Yunnan, extending westwards to Kashmir along the Himalay- as. Therefore, the genus is strictly limited to the Hengduan Mountains and the Himalayas. That is to say, it occupies the whole Sino-Himalayan Floristic Subregion (Fig. 3). This is of great importance for determining the limits of the floristic subregion, and for drawing a more acurate line between the Sino-Japanese Subregion and the Sine-Himalayan Floristic Subregion. The analysis of distribution patterns of species shows that the Hengduan Mountains is the di- stribution centre of the two major groups of Cyananthus, Sect. Stenolobi Franch. and Sect. Annui (Lian) Hong et L. M. Ma. In these two groups, only four out of 12 species, i. e. C. in- canus Hook. f. et Thoms., C. macrocalyx Franch., C. hookeri C. B. Cl. and C. inflatus Ho- ok. f. et Thoms., extend their areas westwards to Sikkim and Nepal. The other section, Sect. Cyananthus also exists in the west of the Hengduan Mountains. Although in the Himalayas oc- cur three major groups of the genus, only the last-mentioned group-Sect. Cyananthus is mainly distributed in the area (Fig. 4). According to the fact, we tend to infer that the Heng- duan Mountains is both the frequency and diversity centers of the genus Cyananthus. The genera of Campanulaceae, which are relatively primitive and the closest relatives of Cyananthus, all oc- cur in SW China and the adjacent regions. Therefore, the region may well be the preserved cen- ter of the primitive genera, or even may be the original center of the Campanulaceae. All data accumulated demonstrate that the genus is very old but still under intensive differ- entiation. With few diagnostic qualitative characters, the characters used
%K Campanulaceae
%K Cyananthus
%K classification
%K systematics
%K biometrics
%K palynology
%K chromosome
%K geographical distribution
桔梗科
%K 蓝钟花属
%K 分类
%K 系统学
%K 生物统计学
%K 孢粉形态学
%K 染色体
%K 地理分布
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=B5EDD921F3D863E289B22F36E70174A7007B5F5E43D63598017D41BB67247657&cid=B47B31F6349F979B&jid=67CDFDECD959936E166E0F72DE972847&aid=91CBC114103BCA897A95DFC1E25A1914&yid=116CB34717B0B183&vid=771469D9D58C34FF&iid=CA4FD0336C81A37A&sid=C5154311167311FE&eid=987EDA49D8A7A635&journal_id=1002-1175&journal_name=中国科学院研究生院学报&referenced_num=0&reference_num=0