A Taxonomic Study on Ischaemum L. (Gramineae) of Taiwan

by Hsieh, Chin-shan

A taxonomic study on Ischaemum of Taiwan has been carried out through the past three years, according to morphological characters including habit, culm, leaf, inflorescence, spikelet, flower and caryopsis. The results indicated that there are totally 5 species of the genus occurring in Taiwan, i. e. Ischaemum aristatum L. var. aristatum (including I. aristatum var. momiyamai (Honda) Hsu) , I. barbatum Retzius (including I. barbatum var. gibbum (Trin.) Ohwi), I. ciliare Retzius (including I. indicum (Houtt.) Merr.), I. rugosum Salisbury (including I. akonense Honda and I. rugosum var. segetum Hackel), and I. setaceum Honda. Because of no specimens available for examination in the herbariums of Taiwan, I. aristatum var. crassipes (Steud.) Yonekura, I. aureum (Hook. & Arn.), I. muticum L., and I. timorense Kunth are treated as doubtful species. In addition, the features of awn, compression and lower glume of spikelets are realized the diagnostic characters to distinguish the species. In this study, the detailed descriptions of and a key to the species and varieties are given. Moreover, the distribution and habitat of each species are also provided.