Carex tianlinensis and C. leigongshanica, Two New Species Related to C. perakensis from Southwest China, Based on Morphological and Molecular Evidence

Two new species of Carex (Cyperaceae), C. tianlinensis and C. leigongshanica, are described and illustrated based on morphological and molecular evidence. Phylogenetic analyses based on two nuclear (ETS and ITS) and three plastid (matK, trnL-F, and rpl32-trnL(UAG)) DNA markers recovered C. tianlinensis and C. leigongshanica as two distinct, strongly supported monophyletic lineages within the Indica clade. The two new species form a well-supported sister pair that is in turn sister to C. perakensis. Morphologically, C. tianlinensis most closely resembles C. perakensis, but differs in having inflorescences arising near the apex of the culms, pistillate part of spikes sparsely 2–6-flowered, and style glabrous. C. leigongshanica is also morphologically similar to C. perakensis, but differs in having each inflorescence with 6–16 shorter spikes, spikes 0.7–1.5 cm long, sessile or subsessile, utricles shorter, 3–3.5 mm long, and leaf blades narrower, 3–5.5 mm wide. Detailed morphological descriptions, type designations, specimen citations, and information on habitat and phenology are provided for the two new species.