Carex sect. Radicales (Kukenthal) Nelmes, 1951

Yang, Haijun, Xu, Han, Deng, Yunfei & Li, Yide, 2017, Carex xueyingiana (Cyperaceae), a new species from Hainan Island, China, Phytotaxa 308 (2), pp. 239-248 : 243

Key to the four species in Carex sect. Radicales -B group

1. Leaves densely hispidulous or pubescent on both surfaces; perigynium attenuate at base and stipitate; style smooth or hairy ..... 2

1’ Leaves glabrous on both surfaces; perigynium base cuneate or subrounded, indistinctly stipitate; style densely brown granularpunctate ............................................................................................................................................................................................. 3

2 Culms densely tufted, longer than or equaling leaves; lowermost bract leaf-like; perigynium 3.5–6.5 mm ...... C. chlorocephalula

2’ Culms loosely tufted, distinctly shorter than leaves; lowermost bract sheath-like, sometimes with a very short setaceous blade; perigynium 2.3–2.5 mm ............................................................................................................................................ C. xueyingiana

3 Culms not exceeding 0.5 mm thick; lowermost bract setaceous; spikes ovate or ovate-oblong, 2–5 mm long; style flat ..... C. tsoi

3’ Culms ca. 1 mm thick; lowermost bract leaf scalelike; spikes cylindric, 5–10 mm long; style cylindric ................... C. planiscapa