[+] 3. Paniceæ. Mostly stouter and narrow-leaved, with thinner spikes; perigynium often strongly nerved, not conspicuously triangular, often somewhat turgid; bracts and sheaths various.—Sp. 75–78.
[+] 4. Bicolores. Small species with a beakless, more or less round or pyriform perigynium, which is commonly glaucous; terminal spike androgynous or all staminate; stigmas mostly 2.—Sp. 79.
[+] 5. Digitatæ. Low species; sheaths membranaceous or hyaline and colored, either not prolonged into a bract or the bract very short and not foliaceous; perigynium more or less three-angled, often hairy, the beak straight or nearly so.—Sp. 80–83.
[*] 7. Sphæridiophoræ. Perigynium mostly short and rounded, three-angled in the Triquetræ, firm or hard in texture, not inflated, hairy or scabrous, the beak straight and usually bifid; staminate spike one; pistillate spikes short (1´ long or less), usually globular or short-oblong, more or less sessile and approximate or the longer ones radical (spike single in n. 84); bracts sheathless, short, or obsolete; stigmas rarely two.—Low species of dry ground, with leaves all radical.
[+] 1. Scirpinæ. Spike one, unisexual; plant diœcious.—Sp. 84.
[+] 2. Montanæ. Spikes two to several, the lowest occasionally long-peduncled and radical; perigynium rounded, contracted above and below, mostly bearing two prominent ribs, more or less hairy.—Low species of dry soils.—Sp. 85–91.
[+] 3. Triquetræ. Taller; spikes mostly approximate at the top of the culm, oblong or cylindrical; perigynium conspicuously 3-angled.—Sp. 92.
[*] 8. Phyllostachyæ. Perigynium much as in the Montanæ; spike one, staminate above; pistillate flowers few, often remote, usually on a more or less zigzag rhachis; scales prolonged and leaf-like.—Sp. 93–95.
[*] 9. Leptocephalæ. Perigynium thin in texture, green, oblong or lanceolate or linear in general outline, beakless; spike one, staminate above, thin and slender; stigmas mostly three.—Small, slender and grass-like.—Sp. 96.
[*] 10. Physocephalæ. Spike one, globular or short-oblong, staminate at the apex; perigynium straw-colored, paper-like, more or less inflated; stigmas three. Leaves remarkably broad in our species.—Sp. 97.