以礼草属的分类研究

A taxonomical study on the genus Kengyilia Yen et J. L. Yang

以礼草属ＫｅｎｇｙｉｌｉａＹｅｎ ｅｔＪ．Ｌ． Ｙａｎｇ 是禾本科Ｐｏａｃｅａｅ 小麦族ｔｒｉｂ ． Ｔｒｉｔｉｃｅａｅ 中新近建立的属，针对其存在问题，对它进行了全面清理，提出了一个新的分类系统。新系统含３ 组、２６ 种、６ 变种，其中３个组为新设立，并包括１ 新种、７ 个新等级、新组合及新异名。此外，还报道了一些类群的分布新记录。

Kengyilia Yen et J L Yang is a recently established genus in trib. Triticeae of Poaceae. In this paper, this genus is taxonomically revised, and a new taxonomic system is presented. The new system includes 3 sections, 26 species and 6 varieties, of which 3 sections and 1 species are described as new, 7 taxa are treated respectively in the ways of new status or combination and reduction. Three new sections, sect. Kengyilia, sect. Stenachyra L. B. Cai and sect. Hyalolepis (Nevski) L. B. Cai, are differentiated by the length and width of spike, the growing position of spikelet, the relative length of glume, the colour of anther and so on. The sect. Kengyilia contains 9 species, distributed in northwestern China, extending westward to Kazakhstan, Kirghizia, Tadzhikistan, Afghanistan and Iran; the sect. Stenachyra L. B. Cai comprises 10 species and 3 verieties, distributed in western China, mainly in the Qinghai Xizang Plateau; and the sect. Hyalolepis (Nevski) L. B. Cai consists of about 7 species and 3 varieties, distributed in western China, extending westward to Kirghizia and Tadzhikistan. Twenty six species of Kengyilia are recognized on the basis of the same criterion of specific concept, and the other taxa below the rank of species are also checked in terms of their external morphology. As a result, Kengyilia pendula L. B. Cai is reported as a new species; K. hirsuta var. obviaristata L. B. Cai is raised to a species; K. melanthera (Keng) J. L. Yang, Yen et Baum is reduced to a variety under K. thoroldiana(Oliver) J. L. Yang, Yen et Baum; Roegneria hirsuta var. leiophylla Keng et S. L. Chen is reduced as a synonym of K. hirsuta var. hirsuta; Agropyron thoroldianum var. laxiusculum Melderis is reduced to K. grandiglumis (Keng et S. L. Chen) J. L. Yang, Yen et Baum; Roegneria rigidula var. intermedia Keng et S. L. Chen to K. rigidula (Keng et S. L. Chen) J. L. Yang, Yen et Baum; R. hirsuta var. variabilis Keng et S. L. Chen and R. melanthera var. tahopaica Keng et S. L. Chen to K. hirsuta (Keng et S. L. Chen) J. L. Yang, Yen et Baum. In addition, new records on the geographical distributions of some taxa are also reported in this paper.