converge apically to form a short mucro; stamens 2 or 3, the anthers about 2 mm. 

 long; style 2-branched, flattened, fimbriate from the base to the point of branch- 

 ing; achene lenticular-obovoid or obpyriform, 1.5-2 mm. long, reddish-brown or 

 dark-brown, often lustrous, scalariform-foveate or reticulate, the individual cells 

 almost isodiametric or horizontally rectangular and usually arranged in numerous 

 fine vertical rows. 



Moist sands or muck of coastal marshes, dune swales or estuary banks (rarely 

 alkaline situations inland), L.I., s. along the Atl. Coast into the Fla. Keys, along 

 the Gulf Coast s. and w. into Tarn, and the Yuc. Peninsula; Bah. I., Cuba. 



10. Fimbristylis pubenila (Michx.) Vahl. Fig. 209. 



Perennial to 1 m. tall; culms solitary or in small tufts, the bases often hard, 

 knotty and jointed together into short thick rhizomes on which the old leaf bases 

 often persist as shreddy remnants; leaves from one third as long to nearly equaling 

 the culms; blades narrowly linear, usually involute at least toward the base, about 

 1 mm. wide, the backs with several raised nerves, smooth to variously pubescent, 

 the upper surface smooth or variously pubescent, the pale margin cartilaginous 

 and ciliate-scabrid (this most noticeable toward the blade-base and -apex); sheathes 

 hard, thick, fibrous, pale- to dark-brown, the broad margin scarious and entire ex- 

 cept for long cilia at apex; ligule inconspicuous, incomplete or absent; longest bract 

 of inflorescence erect, the blade flattened, usually much-surpassed by the inflores- 

 cence; spikelets lance-ovoid to ovoid or ellipsoidal, 5-10 mm. long, reddish-brown, 

 in a usually few-flowered compact to open system of pedunculate cymules or a 

 simple umbel-like cyme; fertile scales ovate to obovate or even reniform, reddish 

 brown to dull-brown or flavescent, the backs rounded, the scarious rounded margin 

 entire and ciliate or somewhat lacerate, the inconspicuous nerves flavescent to 

 pale-brown or sometimes the central ones slightly raised, greenish and slightly 

 excurrent as a short mucro; outer surface of at least the lower scales puberulent 

 at least toward the apex; stamens 3, the anthers 2-2.5 mm. long; style 2-branched, 

 flattened, the edges usually fimbriate from about the midpoint to the base of the 

 style branches; achene lenticular-obovoid, about 1 mm. long, rather flat to stme- 

 what tumid, sometimes umbonate, flavescent to dark-brown, the surface distinctly 

 to faintly reticulate, the rectangular cells usually arranged in several longitudinal 

 lines (1 1 to 20 on a face) in a few cases with very many longitudinal lines with 

 the cells isodiametric, the longitudinal lines prominently to slightly raised. 



Sands, sandy peats or clays of savannahs, edge of ponds, open pinelands, upper 

 edges of grass-sedge bogs, meadows and prairies, throughout the Atl. and Gulf 

 Coastal Plain from L.I. s. into peninsular Fla. and w. to Tex. nearly to the Mex. 

 border; scattered from the cen. Piedmont to its southwest edge; scattered in the 

 interior highlands and of frequent occurrence in the moist meadows and prairies 

 of the cen. lowlands, particularly along the Great Lakes on the Pleistocene shores 

 and w. into the tall and mid-grass prairies of Tex., Okla., Kan. and Neb.; Can. 



11. Fimbristylis puberula var. interior (Britt.) Krai. 



As var. puberula but plant base less bulbous and producing dense clusters of 

 short slender twisted pale-reddish-brown rhizomes; foliage pale-green, sometimes 

 appearing glaucous; blade margins distantly to approximately ciliate-scabrid; ligule 

 inconspicuous or present at a narrow line of short ascending hairs; longest involu- 

 cral bract usually longer than the inflorescence; spikelets ovoid to cylindrical or 

 ellipsoidal, 5-10 mm. long, stramineous to reddish-brown, the backs of the scales 

 usually smooth, the central nerve of at least the lower scales excurrent as a definite 

 terete mucro; achene with several prominent to rather obscure longitudinal ridges 

 that are interconnected with finer horizontal lines, hence the surface composed of 

 longitudinal rows of roughly isodiametric shallowly concave cells. 



413 



