关键词: 石斛属, 兰科, 新记录, 地理分布, 西藏, 中国

Abstract: Dendrobium is the second largest genus of Orchidaceae, distributed in southern and southwestern China. The number of Dendrobium is large, but some taxa have not been discovered. During the investigation of orchid resources in Xizang, two Dendrobium species were discovered, which were identified as D. macraei Lindl. and D. ritaeanum King & Pantl. Both were recorded for the first time in China. The results are as follows: D. macraei is similar to D. plicatile, with the difference that the edge of the middle lobe of lip is entire, apex concave; D. ritaeanum is similar to D. angustifolium, the flowers of the former are very small, and sepals and petals do not have purple stripes, and the lip is triangular up to 1.4 cm in length. The detailed morphological characteristics and photographs of the two species are provided. The specimens are stored in the Herbarium of Xizang Agricultural and Animal Husbandry University. This discovery enriches the local data and the potential medicinal plant resource reserve of orchids in China, and is of great significance to the biodiversity study of orchids and the investigation of medicinal orchid resources.

Key words: Dendrobium, Orchidaceae, new records, geographical distribution, Xizang, China