Carex sect. Occlusae

Lu, Yi-Fei, Jin, Xiao-Feng & Yu, Ming-Jian, 2022, Carex borealifujianica (Cyperaceae), a new species of the core Carex clade from Fujian, southeastern China, PLoS ONE (e 0264419) 17 (3), pp. 1-18 : 11-15

Key to the species in Carex sect. Occlusae from China (mainly modified from Flora of China [ 14]).

1a. Spikes approximate, usually aggregated at top of culm, subcapitately disposed; bracts aggregated.

2a. Culms 12–15 cm tall; leaf blade 2–5 mm wide; utricles 2.3–2.5 mm long, ciliate on margins of beak.. ... ... ... ... ... ... ... ... ... .... ... ... ... ... ... ... ... ... .... .1. C. pseudophyllocephala L.K. Dai

2b. Culms 20–60 cm tall; leaf blade 8–15 mm wide; utricles 2.8–3.5 mm long, densely hispidulous.. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .... .2. C. phyllocephala T. Koyama

1b. Spikes remote, racemosely disposed; bracts sparsely disposed.

3a. Pistillate scales connate at base; pistillate spikes with sparse utricles; utricles subrhombic, trigonous, 5–5.3 mm long.. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .... 3. C. poculisquama Kük.

3b. Pistillate scales not connate; pistillate spikes with dense utricles; utricles ovoid or obovoid, obtusely trigonous, 3–4.8 mm long.

4a. Leaf blade 2–4 mm wide; pistillate spikes 3–4 mm wide; utricles sparsely disposed, subdistichous.

5a. Staminate spikes 4–7.5 cm long; staminate scales oblanceolate, 7–8.5 mm long; utricles 3–3.6 mm long, glabrous.. ... ... ... ... ... ... ... ... ... ... ... .... ..4. C. nodosa S.R. Zhang et al.

5b. Staminate spikes 1.5–2.5 cm long; staminate scales broadly obovate, 1.5–2 mm long; utricles 3–3.2 mm long, densely hispidulous.. ... ... ... ... ... ... .... 5. C. hebecarpa C.A. May.

4b. Leaf blade 2.5–15 mm wide; pistillate spikes 3.8–6 mm wide; utricles densely disposed, multiseriate.

6a. Utricles 3–5 mm long, densely hispidulous.

7a. Leaf sheaths not overlapping, sheaths rather loosely enveloping culms; utricles 3.8– 5 mm long.

8a. Leaf blade 2.5–5 mm wide, sheaths sparsely pilose; staminate spikes 2 or 3, clavate; achenes emarginate at apex.. ... .... 5. C. borealifujianica Y.F. Lu & X.F. Jin

8b. Leaf blade 5–15 mm wide, sheaths glabrous; staminate spike solitary, cylindrical; achenes acute at apex.. ... ... ... ... ... ... ... ... ... ... ... ... .... 6. C. ligulata Nees

7b. Leaf sheaths overlapping, sheaths tightly enveloping culms; utricles 3–3.2 mm long-.. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .... .....7. C. maubertiana Boott

6b. Utricles 3–3.5 mm long, hispidulous on upper margins and veins........9. C. pseudoligulata L.K. Dai