Carex ledongensis (Cyperaceae), a new sedge from Hainan Isl. Of South China Author Yang, Hu-Biao 0000-0002-7380-8874 Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, China. & yanghubiao @ 163. com; https: // orcid. org / 0000 - 0002 - 7380 - 8874 Author Liu, Guo-Dao 0000-0003-4189-9959 Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, China. & liuguodao 2008 @ 163. com; https: // orcid. org / 0000 - 0003 - 4189 - 9959 text Phytotaxa 2020 2020-10-02 461 2 72 78 http://dx.doi.org/10.11646/phytotaxa.461.2.1 journal article 10.11646/phytotaxa.461.2.1 1179-3163 4784542 Key to the species of Carex sect. Mitratae species occurring in Hainan . 1a. Nutlets contracted on angles...................................................................................................................................... C. tungfangensis 1b. Nutlets not contracted on angles.........................................................................................................................................................2 2a. Lateral spikes androgynous; nutlets 5–6 mm long ..................................................................................................... C. ledongensis 2b. Lateral spikes unisexual; nutlets size less than 3 mm long ................................................................................................................3 3a. Terminal spike oblong; perigynia nearly equaling glume, obovate; nutlets ca. 1.8 mm long...................................... C. breviculmis 3b. Terminal spike linear-cylindric; perigynia longer than glume, ovate-fusiform; nutlets 2–2.5 mm long......................... C. tristachya