Notes on Carex (Cyperaceae) from China (X): new species and variety of sections Clandestinae and Rhomboidales

Carex L. is one of the largest angiosperm genera and the most species-rich genus of flowering plants in China. Three new species and one new variety belonging to Carex sect. Clandestinae and sect. Rhomboidales are described and illustrated. Carex zhangjiajieensis (sect. Clandestinae ) differs from the morphologically similar species C. shuchengensis in having lateral peduncles exserted from bract sheaths, utricles slightly longer than or subequal to pistillate glumes and ventrally veinless, and nutlet beaks that are erect and ca. 0.2 mm long. Within sect. Rhomboidales , C. glaucispicata ( sp. nov .) differs from C. cheniana by its dwarf habit, shorter pistillate spikes, and narrower leaves. Carex liboensis ( sp. nov .) differs from the related species C. austrosinensis in having rather densely flowered lateral spikes, lateral peduncles enclosed in bract sheaths, and nutlets shallowly constricted at the three middle angles. Carex canina var. pubiutriculata ( var. nov .) differs from the autonymic variety in having both pubescent utricles and bract sheaths.