GENUS 12. 



SEDGE FAMILY 



i. Dichromena colorata (L.) Hitchcock. 

 Narrow-leaved Dichromena. Fig. 839. 



Schoenus coloratus L. Sp. PI. 43. i/53- 

 D. Icucocephala Michx. Fl. Bor. Am. i : 37. 1803. 

 Dichromena colorata A. S. Hitchc. Ann. Rep. Mo. 

 Bot. Card. 4: 141. 1893. 



Glabrous, culm slender, erect, rather sharply 

 triangular, i-2 tall. Leaves distant, narrowly 

 linear, about i" wide, much shorter than the 

 culm, those of the involucre 4-6, reflexed when 

 mature, yellowish-white at the base ; head glo- 

 bose, 6"-io" in diameter ; spikelets narrowly 

 oblong, acute ; scales membranous, lanceolate, 

 nearly white, i-nerved, subacute at the apex; 

 achene obovate, brown, papillose or wrinkled 

 transversely, nearly truncate at the summit, com- 

 pressed, covered by the truncate-based tubercle. 



In moist sandy soil, New Jersey to Florida and 

 Texas. Bermuda ; tropical America. June-Sept. 



2. Dichromena latifolia Baldw. Broad- 

 leaved Dichromena. Fig. 840. 



Dichromena latifolia Baldw. ; Ell. Bot. S. C. & 

 Ga. i : 90. 1816. 



Culm stout, obtusely triangular or nearly 

 terete, the leaves lanceolate or linear-lanceo- 

 late, tapering gradually to a long-acuminate 

 apex from a broad base, ii"-4" wide, some- 

 times -overtopping the culm, but the lowest 

 much shorter, those of the involucre 7-10, 

 strongly rerlexed when old. Head globose, 

 6"-o." in diameter; spikelets oblong, subacute; 

 scales ovate-lanceolate, nearly white, rather 

 obtuse; achene nearly orbicular in outline, pale 

 brown, faintly wrinkled transversely and lon- 

 gitudinally, so as to appear reticulated ; tu- 

 bercle decurrent on the margins of the achene. 



In wet pine barrens, Virginia to Florida and 

 Texas. June-Aug. 



13. RYNCHOSPORA Vahl, Enum. 2: 229. 1806. 



Leafy sedges, mostly perennial by rootstocks, with erect 3-angled or terete culms, nar- 

 row 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). Sta- 

 mens 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 aurca Vahl. BEAK-SEDGE.. 



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

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

 Bristles minute or wanting. 

 Bristles plumose. ' 



Bristles downwardly barbed or rarely smooth. 

 Scales white or nearly so ; bristles 9-15. 

 Scales brown ; bristles 6. 



Leaves filiform ; achene oblong. 



Leaves narrowly linear, flat ; achene obovate. 



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

 Bristles reaching or exceeding the end of the tubercle, which is 

 Spikelets few-several in numerous rather loose clusters. 

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

 Bristles upwardly barbed. 



Spikelets numerous in 2-6 very dense globose heads. 



1. R. corniculata. 



2. R. pallida. 



3. R. oligantha. 



4. R. alba. 



5. R. capillacea. 



6. R. Knicskcruii. 

 as long as the achene. 



7. R. glomerata. 



8. R. a.rillaris. 



8. R. a.rillaris. 



