[++][++] Bristles always none; culm leafy.
5. Dichromena. Spikelets crowded into a leafy-involucrate head, laterally flattened, the scales more or less conduplicate and keeled. Many of the flowers imperfect or abortive.
6. Psilocarya. Spikelets in broad open cymes. Style almost wholly persistent.
7. Fimbristylis. Spikelets in an involucrate umbel. Culm leafy at base. Style usually wholly deciduous.
[+][+] Style not bulbous at base.
[++] Flowers without inner scales, but bristles generally present.
8. Scirpus. Spikelets solitary or clustered, or in a compound umbel, the stem often leafy at base and inflorescence involucrate. Barbed bristles 3–8 or none. Stamens mostly 3.
9. Eriophorum. As Scirpus, but the bristles naked, exserted and often silky in fruit. Stamens 1–3.
[++][++] Flower with one or more inner scales.
10. Fuirena. Scales of the spikelet awned below the apex. Flower surrounded by 3 stalked petal-like scales alternating with 3 bristles.