Abstract

New species – Chionographis actinomorpha (Melanthiaceae) discovered on the border of central Vietnam and Laos is described and illustrated. Standard citations of type specimens, description, name etymology, data on ecology, phenology and distribution, as well as short taxonomic remarks for the new species are provided. The species differs from all its congeners in having antrorse, actinomorphic flowers with tepals of the same length. This fact may also imply that this new species retains more primitive character states than any other species of this genus. Discovery of this species in middle-east Indochina remarkably extends the generic range hitherto known to the far southwest.

中文摘要

本文新發現一種在越南中部與寮國邊界的白絲草屬新種Chionographis actinomorpha，並提供模式標本引用、分類描述、命名詞源、生態習性、物候學及地理分布等資訊。本種花直立，輻射對稱，且花被片等長等特徵與同屬其它物種具有明顯的差異。本種的發現也大大擴展了白絲草屬在中南半島最南的分布範圍。

Keyword: Chionographis actinomorpha, Laos, Melanthiaceae, new species, plant diversity, plant taxonomy, Vietnam.