Abstract

The umbrella sedge Cyperus involucratus was misidentified as C. alternifolius subsp. flabelliformis in Taiwan. The investigation of the status of the umbrella sedge is prompted by the recent discovery of C. alternifolius which was naturalized to eastern Taiwan. Cyperus alternifolius, though similar to C. involucratus in appearance, differs on the fine structure of achene surface, bract margin, etc. In this article, we report the newly naturalized plant, compare the differences of characteristics between the species, and provide the photos of habitat and fine structure for taxonomic identification.

中文摘要

輪傘莎草在臺灣一直被鑑定為「Cyperus alternifolius L. subsp. flabelliformis (Rottb.)Kukenth.」，其正確學名應為「Cyperus involucratus Rottb.」。本研究同時發現新近歸化於東臺灣之光桿輪傘莎草 (新擬中名；Cyperus alternifolius L.)，其外形雖然與輪傘莎草酷似，但瘦果表皮、苞片外緣等微細構造有所不同。本文除報導新歸化種光桿輪傘莎草外，並列表比較光桿輪傘莎草與輪傘莎草之形態差異，同時提供生態及微細構造照片，做為鑑定之參考。

Keyword: Cyperus, Cyperus alternifolius, Cyperus involucratus, naturalized plant, Taiwan, Taxonomy. 莎草屬、光桿輪傘莎草、輪傘莎草、歸化植物、臺灣、分類。