J Syst Evol ›› 1991, Vol. 29 ›› Issue (3): 193-229.

• Research Articles •     Next Articles

A Taxonomic Study on the Genus Polygala L. in China

Chen Shu‐Kun   

  • Published:1991-05-10

Abstract: 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.

Key words: Polygala, pollen morphology, Taxonomy, System, China