50 CYPEBACEAE. 



pubescent branches about as long as the glabrous lower part ; achene obovoid. 

 dull black, bluntly trigonous, nearly 1 mm. long, capped by a minute de- 

 pressed tubercle. 



Castle Island and Little Inagua. Endemic. Wilson's Stexophyllus. 



4. FIMBRISTYLIS A T ahl, Enum. 2: 285. 1806. 



Annual or perennial sedges. Culms leafy below. Spikelets umbellate or 

 capitate, terete, several to many-flowered, subtended by a 1-many-leaved in- 

 volucre, their scales spirally imbricated all around, mostly deciduous, all fertile. 

 Perianth none. Stamens 1-3. Style 2-3-cleft, pubescent or glabrous, its base 

 much enlarged, falling away from the summit of the achene at maturity. 

 Achene lenticular, biconvex, or 3-angled, reticulated, eancellate, or longitudi- 

 nally ribbed or striate in our species. [Greek, in allusion to the fringed style 

 of some species.] A large genus, the species widely distributed in temperate 

 and tropical regions. Type species: Fimbristylis acuminata Vahl. 



Style branches 2 ; achene lenticular. 



Achene longitudinally ribbed. 1. F. diphylla. 



Achene eancellate. reticulate or granular, not ribbed. 



Scales pilose-puberulent ; leaves short. 2. F. fcrruginea. 



Scales glabrous. 



Leaves elongated : inflorescence loose. 



Leaves involute or plano-convex. 3. F. castanea. 



Leaves flat. 4. F. inaguensis. 



Leaves short : inflorescence compact. 5. F. spathacea. 



Style branches 3 ; achene trigonous. 6. F. hirta. 



1. Fimbristylis diphylla (Retz.) Vahl, Enum. 2: 289. 1806. 



Scirpus diphyllus Retz. Obs. 5: 15. 1789. 



Perennial by short rootstocks, glabrous or pubescent; culms tufted, 1-6 

 dm. high, slender. Leaves 1-3 mm. wide, shorter than the culm ; involucre- 

 bracts 3 or 4, shorter than or surpassing the simple or compound umbel; spike- 

 lets oblong or ovoid, 5-10 mm. long, 2.5-4 mm. thick; scales ovate, acute, 

 glabrous ; style 2-cleft ; aehenes scarcely 1 mm. long, obovoid, biconvex, white 

 or yellowish, longitudinally ribbed, reticulated, the ribs smooth. 



Moist soil. New Providence and Fortune Island : southern United States ; 

 West Indies ; tropical continental America : Old World tropics. Slender Fimbri- 

 stylis. 



^ 2. Fimbristylis ferruginea (L.) Vahl. Enum. 2: 291. 1806. 



Scirpus ferrugineus L. Sp. PI. 50. 1753. 



Culms tufted, erect, 2-8 dm. tall, rather slender. Leaves much shorter 

 than the culm, often very short ; involucre-bracts 2-4, rarely exceeding the 

 simple or slightly compound umbel; spikelets few or several, ovoid-oblong, 

 8-20 mm. long, 3-4 mm. thick; scales ovate, acutish or mucronulate, brown, 

 pilose-puberulent toward the apex; style 2-cleft; achene obovoid, biconvex, 

 smooth, brownish, half as long as the scale. 



Moist saline soil. Berry Islands, Cat Cav. Andros. New Providence and 

 Eleuthera to Mariguana and Inagua : West Indies ; continental tropical America. 

 Salt Marsh Fimbristylis. 



3. Fimbristylis castanea (Miehx.) Vahl, Enum. 2: 292. 1806. 



Scirpus castaneus Miehx. El. Bor. Am. 1: 31. 1803. 



Perennial; glabrous; culms stiff, slender, wiry, trigonous, 3-10 dm. high. 

 Leaves rigid, involute, usually somewhat shorter than the culm, about 2 mm. 

 wide when unrolled, their sheaths often brown, those of the involucre 3-6, the 



