10. Rhynchospora oligantha Gray. Fig. 246. 



Tufted perennial; culms 15-45 cm. long, erect or ascending, 0.3-0.6 mm. 

 thick; leaves filiform-setaceous, resembling the stems; inflorescence of a lax 

 terminal fascicle and usually a remote reduced axillary one, each fascicle with 

 only 1 to 3 spikelets; spikelets on slender individual pedicles 3-10 mm. long, 

 narrowly ovoid, pale-brown, 4-7 mm. long, usually with 2 fruit (1 to 3); bristles 

 6, in the lower half densely plumose, slightly shorter than the body; achenial 

 body 2.3-2.6 mm. long, broadly ovate, dark-brown when mature, very turgidly 

 biconvex, transversely wrinkled, apically prounoncedly narrowed into a definite 

 hour-glassed-shaped turbercle base, tubercle very short-conic, 0.3-0.6 mm. long. 



Rare in bogs and open seepage slopes, in e. Tex. (Austin, Henderson, Smith 

 and Waller cos.), spring (May-early June); N.J., Del., N.C., Ga. and Gulf States; 

 Gr. Ant.; C.A. 



11. Rhynchospora plumosa Ell. Fig. 246. 



Tufted perennial; culms wiry, 2-4 dm. long, erect, 0.6-1.1 mm. thick, basally, 

 stamineous; leaves setaceous-filiform, numerous, often curling toward the ends; 

 lower bracts of the fascicles elongate, wiry, like the leaves, far-surpassing the 

 inflorescence; inflorescence compact, congested, terminal, 1-3 cm. long, about 

 1 cm. thick, often spikelike; spikelets pale- to dark-brown, lance-elliptic, 3-4 mm. 

 long, usually with 1 or 2 fruits; bristles 6, densely plumose in the lower part; 

 achenial body broadly obovate, 1.4-1.8 mm. long, brown, turgid, transversely 

 wrinkled, not narrowed apically; tubercle short-conic, about 0.5 mm. long, brown. 

 R. semi plumosa Gray. 



Infrequent in wet soils along streams and in savannah-evergreen shrub bogs, 

 in s.e. Tex. (Hardin, Tyler and Newton cos.), Apr.-May; coastal flats, N.C. to 

 Tex.; Cuba. 



12. Rhynchospora filifolia Gray. Fig. 247. 



Tufted perennial; culms 3-6 dm. long, about 1 mm. thick near the base, erect, 

 wiry; leaves mostly involute, resembling the culms; inflorescence a terminal very 

 dense round-topped fascicle 10-15 mm. broad, plus usually one reduced fascicle 

 in the next lowest axil; spikelets cinnamon-brown, lanceolate, 3-5 mm. long, with 

 3 to 10 flowers, the 2 to 6 achenes and their scales quickly falling in acropetal 

 succession, upon maturation only 1 or 2 mature achenes present at any one time 

 and these usually exposed by the rapid shedding of the scales; bristles 6, usually 

 surpassing the tubercle, minutely antrorsely barbed; achenial bodies obovate, 

 0.9-1 mm. long, biconvex, the 2 polished smooth faces brown or the central por- 

 tions paler, buffy, tubercle deltoid, grayish, compressed, acute, 0.4-0.6 mm. long. 



Rare in moist loam and wet areas in savannahs, in e. Tex. (Hardin and Waller 

 COS.), summer; coastal areas, N.J. to Tex.; Cuba. 



13. Rhynchospora fascicularis (Michx.) Vahl. Fig. 248. 



Tufted perennial; culms 5-13 dm. long, 1.5-2.5 mm. thick basally, subterete 

 or obtusely 3-angled, leafy; leaves 1-4 mm. broad; inflorescence a crowded 

 terminal group of 1 to 3 fascicles (about 1 cm. broad and overtopped by the 

 setaceous bracts) plus usually 1 (rarely 2) remote similar axillary fascicles below; 

 spikelets 3.5-5 mm. long, lanceolate, cinnamon-brown, several-flowered and 

 -fruited, the scales caducous in acropetal succession, each falling just before 

 maturation of its achene; bristles about 6, minutely antrorsely serrulate or barbed; 

 achenial body nearly orbicular, biconvex, very dark-brown or fuscous except for 

 a buff'y spot in the center of each of the 2 smooth faces, 1.4-1.5 mm. long; 

 tubercle deltoid, 0.4-0.7 mm. long, much-compressed, grayish. 



478 



