198 



CYPERACEAE (SEDGE FAMILY) 



3. F. simplex Vahl. Perennial, 1-8 dm. high; leaf-sheaths 

 hairy; perianth-scales ovate-oblong, the retrorsely barbed awns 

 arising from below the tip, bristles equaling or exceeding the 



)8. F. simplex, white achene. — Sandy or saline soil, Mo. and Kan. to Mex. 



Fruit X 22/3. Aug. -Oct. Fig. 308. 



12. HEMICARPHA Nees & Am. 



809. H. micrantha. 



Plant X 2/3. Spikelet x 22/3. 



Achene x 10. 



Spikelet, flowers, etc., as in Scirpus, except that 

 there is a minute translucent scale (readily overlooked) 

 between the flower and the axis of the spikelet. Sta- 

 men only 1. Style 2-cleft. Bristles or other perianth 

 none. (Name from tjjjli-, half, and Kdpcpos, straw or 

 chaf, in allusion to the single inner 

 scaielet.) 



1. H. micrantha (Vahl) Britton. 

 Dwarf or minute annual (0.2-15 dm. 

 high); involucre 1-leaved, as if a 

 continuation of the bristle-like culm, 

 and usually with another minute 



leaf; spiJcelets, l-S, short-cylindric or ovoid (2-4 mm. long) ; 

 scales oblong or narrowly obovate, brown, tipped with a short 

 recurved point ; achenes cijlindric, brown, slightly reticulated, 

 ivith many close rows of crowded low papillae. {H. sub- 

 squarrosa Nees.) — Sandy borders of ponds 

 and rivers, N. H. to Fla., w. to the Pacific ; 

 chiefly on the coastal plain and in the flat 

 country of the interior. Aug. -Oct. (Mex., 

 S. A.) Fig. 309. 



2. H. Drumm6ndi Nees. Similar ; scales broadly obovate 

 or rhombic, the broad green inidrib barely projecting as a blunt 

 appressed tip ; achenes narrowly obovoid, ashy, scarcely reticu- 

 lated, the papillae fewer and somewhat remote. — Damp sand, 

 etc., w. Ont., Ind., and 111. to Ark., Kan., and Tex. July- 

 Oct. Fig. 810. 



3. H. occidentalis Gray. Srdkelets globose, the wide-spread- 

 ing lanceolate or narrowly ovate scales tapering to slender re- 

 curved awns {as long as the blades) ; achenes as in the latter. 

 — Damp sand, w. Ont. ; Wash, to Cal. July-Oct. Fig. 311. 



310. H.Drummondi. 

 Spikelet x 22/3. 

 Achene x 10-. 



811. H. occidentalis. 

 Spikelets x 22/3, 



Achene x 10. 



13. LIPOCArPHA R. Br. 



Spikelets terete, many-flowered, in a terminal close cluster 

 involucrate by leafy bracts. Scales spatulate, regularly im- 

 bricated in many ranks, awnless, deciduous, a few of the 

 lowest empty. Inner scales (bractlets) 2 to each flower, thin, 

 one between the scale of the spikelet and the flower, one 

 between the latter and the axis of the spikelet. Stamens 1 

 or 2. Style 2-3-cleft. Achene flattish or triangular, naked 

 at the tip. — Culms leafy at base. (Name formed of X/ttoj, 

 fat, and Kdp<pos, chaff, from the thickness of the inner scales 

 of some species.) 



1. L. maculata (Michx.) Torr. Annual; culm (0.5-2.5 

 dm. high) much longer than the linear concave leaves ; 

 spikelets (3-7 mm. long) green and dark-spotted ; inner 

 scales delicate ; stamen 1 ; achene oblong with a contracted 



base. — Springy or miry places, Va. to Fla. ; near Philadelphia, probably adv. 



July-Oct. Fig. 312. 



812. L. maculata. 



