Leafy sedges, mostly perennial by rootstocks, with erect 3-angled or terete culms, narrow flat or involute leaves, and ovoid oblong or fusiform, variously clustered spikelets. Scales thin, i-nerved, imbricated all around, usually mucronate by the excurrent midvein, the lower empty. Upper flowers imperfect, the lower perfect. Perianth of 1-20 (mostly 6) upwardly or downwardly barbed or scabrous bristles, wanting in some species (no. 2). Stamens commonly 3. Style 2-cleft, 2-toothed or rarely entire. Achene lenticular or swollen, not 3-angled, smooth or transversely wrinkled, capped by the persistent base of the style (tubercle), or in some species by the whole style. [Greek, referring to the beak-like tubercle.]

About 200 species, widely distributed, most abundant in warm regions. Besides the following, some 35 occur in the southern United States. Type species: Rynchospora aurea Vahl. Beak-sedge.

Style entire or 2-toothed, persistent as a long-exserted subulate beak.

1.

R. corniculata.

Style deeply 2-cleft, only its base persistent as a tubercle.

Bristles minute or wanting.

2.

R. pallida.

Bristles plumose.

3.

R. olieantha.

Bristles downwardly barbed or rarely smooth.

Scales white or nearly so; bristles 9-15.

4.

R. alba.

Scales brown; bristles 6.

Leaves filiform: achene oblong.

5.

R. cabillacea.

Leaves narrowly linear, flat; achene obovate.

Bristles equalling the achene; tubercle one-half as long or less.

6.

R. Knieskernii.

Bristles reaching or exceeding the end of the tubercle, which is as long as the achene.

Spikelets few-several in numerous rather loose clusters.

7.

R. glomerata.

Spikelets very numerous in 2-6 very dense globose heads.

8.

R. axillaris.

Bristles upwardly barbed.

Spikelets numerous in 2-6 very dense globose heads.

8.

R. axillaris.

Spikelets few-several in rather loose clusters.

Achene smooth.

Leaves setaceous; achene obovate, shining.

9.

R. fusca.

Leaves narrowly linear.

Achene broadly oval.

10.

R. gracilenta.

Achene narrowly obovate.

11.

R. Smallii.

Achene transversely wrinkled.

Spikelets ovoid, in erect cymose clusters; achene longer than the bristles.

Leaves flat; spikelets nearly or quite sessile.

12.

R. cymosa.

Leaves involute; spikelets distinctly pedicelled.

13.

R. Torrcyana.

Spikelets spindle-shaped, in drooping panicles; bristles long.

14.

R. inexpansa.