Two extraordinary new pseudopetiolate Carex species from Vietnam (sect. Hemiscaposae, Cyperaceae)

Carex kucyniakii is a poorly known, morphologically unusual Vietnamese sedge (sect. Hemiscaposae, Cyperaceae) that is part of an early diverging lineagewithin the genus. Fieldwork in Lào Cai Province resulted in the rediscovery of this species near its type locality and the detection of significant variation in the morphology of plants in nearby populations. Subsequent morphological andmolecular studies revealed that C. kucyniakii is a complex of three species. These taxa are endemic to the southern slopes of the Hoàng Lien Mountains, in Lào Cai Province, and exhibit extraordinary morphological features including the widest leaves known for any Cyperaceae (pseudopetiolate and up to 12 cm), and for some taxa pink-red inflorescences. Of the three species recognized in the complex, C. kucyniakii is characterized by a combination of glabrous perigynia, scales, and peduncles, while in C. geographica sp. nov. and C. thinii sp. nov. these structures are pubescent/scabrous. In addition, the sca...