Xiang-yun Zhu's research while affiliated with Chinese Academy of Sciences and other places

The name Oxytropis xinglongshanica C. W. Chang was not validly published in 1987 because two types were indicated. The name is validated here.

This paper provides a taxonomic revision of Gueldenstaedtia (Fabaceae). Four spe-cies and one form are recognized. The revision is based on herbarium material and includes pollen and seed morphological observations. I treat the genus as distinct from the closely related Tibetia based on pollen and seed morphology, other morphological characters and chromosome data. A number of names in Gueldenstaedtia are reduced to synonyms. A key to all species of the genus is provided. For each taxon, its description, ecology, phenology, notes and an illustration and distribution map are also provided.

A new white-flowered form is de- scribed as Tibetia himalaica (Baker) H. P. Tsui for- ma alba X. Y. Zhu (Leguminosae) from Sichuan Province, China.

Oxytropis lhasaensis X.Y. Zhu sp. nova (Fabaceae) from Xizang in China is described and illustrated. It belongs to Oxytropis sect. Sericopetala and is related to O. sericopetala and O. parasericopetala. Supplementary taxonomic notes on this section are provided.

The pollen morphology of Gueldenstaedtia gansuensis. G. gracilis, G. henryi, G. monophylla. G. mutijlora, G. stenophylla. and G. verna and Tibetia liangshanensis, T. tongolensis, T. yadongensis. T. coelestis, and T yunnanensis are reported for the first time. The seed morphology of G. gracilis, G. maritima. G. monophylla, G. mutiflora, G. taihangensis, and G. verna and L coelestis, T. himalaica, T. yunnanensis, and T. yadongensis are firstly described here. In pollen morphology, the differences of pollen grains of Gueldenstaedtia and Tibetia are as follows: Gueldenstaedtia with pollen grains 3–colporate, psilate, and shapes spheroidal, sometimes subprolate, prolate or oblong; and Tibetia with pollen grains 3– and 4–colporate, perforate, shapes spheroidal, sometimes subprolate or prolate. These results, combined with the data of the basic chromosome number x=7 of Gueldenstaedtia and x=8 of Tibetia, support that the two genera should be recognized as two distinct genera, which are consistent with their morphological characters: Gueldenstaedtia with 2 upper lobes of calyx free, stipules free, adnate to petiole, and Tibetia with 2 upper lobes of calyx connate, stipules connate and opposite to leaves. In Tibetia, two types of pollen grains, 3– and 4–colporate pollen grains, are found. Regarding seed morphology: Gueldenstaedtia has circular depression, irregular circular depression or irregular circular reticulation on the surface; Tibetia has smooth surface. The differences in seed morphology of the two genera also support that they should be kept separate. The pollen morphology supports that G. gansuensis, G. gracilis, G. multiflora, G. stenophylla, and G. verna should be reduced into one species consistent with their morphological characteristics. The pollen grains of G. henryi are different from those of the other species in having wide colpi.

A new species of Oxytropis (Legumi-nosae) from Xizang (Tibet) in China, O. qamdoensis X. Y. Zhu, Y. F. Du & H. Ohashi, is described and illustrated. The new species is very similar to O. ochrantha (sect. Baicalia Steller ex Bunge) and shares with it verticillate and opposite leaflets and glandular hairs, but differs in having leaflets with 9–11 whorls per leaf, the standard bilobed at the apex, wings emarginate at the apex, the beak of the keel-petals 1.0–1.5 mm long, and pods with white-tinged hairs. Oxytropis DC., a genus belonging to the tribe Galegeae of Papilionoideae in the Leguminosae, comprises about 300 species occurring in cold mountainous regions of Europe, Asia, and North America, and is most numerous in Central Asia (Polhill, 1981). Bunge (1874) classified 181 species of Oxytropis into 4 subgenera and 19 sections. For Chinese Oxytropis, 125 species, 4 varieties, and 4 forms were grouped into 3 subgenera and 20 sec-tions (Zhu & Ohashi, 2000). Section Baicalia Stell-er ex Bunge now contains 16 species (including the one described here), which are a part of 119 spe-cies in the subgenus Oxytropis in China. The sec-tion can be distinguished from the other sections by having verticillate and opposite leaflets and plants with glands (Zhu & Ohashi, 2000).