Chimonobambusa pleiacantha (Poaceae, Bambusoideae), a new species from southeast Sichuan, China

Chimonobambusa pleiacantha, a newly-identified species of the genus Chimonobambusa Makino from southeast Sichuan, China, is meticulously described and illustrated herein. It is morphologically similar to Ch. tuberculata, but differs in having 4-angled internodes, thicker wall to 4.5-8.5 mm, more reclinate and elongated root thorns to 5-8 mm long, culm internodes with three grooves and two longitudinal ridges on the branch-bearing side, persistent culm leaves, densely brown-purple setose at the bottom of culm leaf sheaths together with sheath scar, developed foliage leaf fimbriae, 6-8 on each shoulder, ca. 3-8 mm long, abaxially white pubescent foliage leaf blades. Phenologically, new shoots usually appear in September to October. In the light of these key morphological and phenological characteristics, Ch. pleiacantha was identified as a new species of the genus Ch. Makino which is different from published species of this genus.