[*] 3. Microrhynchæ. Parallel with [*] 2; distinguished in general by the much smaller and nearly or entirely beakless and mostly entire-mouthed perigynium, which is much thinner in texture; stigmas 2 or 3. Paludose and alpine species, of various habit, mostly with colored spikes, often in dense tufts or tussocks.
[+] 1. Atratæ. Terminal spike club-shaped and androgynous with the staminate flowers below (very rarely all staminate in n. 32); pistillate spikes mostly short and dark-colored, erect or drooping; stigmas 3.—Sp. 30–32.
[+] 2. Rigidæ. Mostly stiff, with short erect closely flowered spikes, an entirely staminate terminal spike, dark colored scales, and bracts with purple or black auricles at base; stigmas 2 or 3.—Sp. 33.
[+] 3. Acutæ. Mostly larger and more slender, usually paludose, with green or light-colored large and long spikes; stigmas 2 (3 in n. 39). Distinguished from [+] 2 mainly by habit.—Sp. 34–39.
[+] 4. Cryptocarpæ. Large, with nodding or drooping large spikes, their dark scales very long and conspicuous; stigmas 2.—Sp. 40, 41.
[+] 5. Pendulinæ. Distinguished from [+] 4 by the smaller size, smaller spikes, sheathless bracts, and whitish, more or less granulated, nearly pointless perigynium; stigmas 3.—Sp. 42–45.
[*] 4. Hymenochlænæ. Perigynium mostly light green or whitish, usually thin and membranous, often somewhat inflated or loosely investing the achene, commonly smooth and shining (hairy in n. 46, sometimes in n. 47), slender or oblong, attenuate to a distinct or long minutely toothed straight beak (or beakless or nearly so in [+] 1 and n. 55); pistillate spikes several or many, mostly loosely flowered and on filiform nodding or widely spreading peduncles; bracts leaf-like; terminal spike staminate or androgynous; stigmas 3. Mostly rather tall and slender upland species.
[+] 1. Virescentes. Terminal spike pistillate at top; pistillate spikes oblong or cylindrical, dense, erect; perigynium ovate or obovate, nearly or quite beakless, often hairy.—Sp. 46, 47.
[+] 2. Sylvaticæ. Terminal spike all staminate; pistillate spikes mostly long-exserted, slender; perigynium few-nerved, contracted into a cylindrical beak which is longer than the body.—Sp. 48.
[+] 3. Flexiles. Terminal spike all staminate; pistillate spikes rather thick (very small in n. 50), more or less drooping; perigynium beaked, few-nerved or nerveless, tawny or whitish.—Sp. 49, 50.