362 CYPERACE^. Hemicarpha. 



rare. Fl. July - August. Fr. August and September. I suspect that T. geminijlora and 

 T. autumnalis of Nees, are scarcely distinct from this species. Kunth refers Sc. mucronu- 

 latus, Michx. to his Fimhristylis autumnalis. 



Tribe IV. HYPOLYTREJE. Nees. 



Flowers perfect. Scales of the spikes imbricated on all sides, each one-flowered ; the flowers 

 with a i — A^-valved {not bristle-form) perigynium. 



10. HEMICARPHA. Nees in Wight ^ Am. contrib. p. 92, and Cyp. in Endl. ^ Mart. 



fl. Bras. p. 61. HEMICARPHA. 



[ From the Greek, ?iemistts, half, and karphos, straw or sedge ; in allusion to the flowers having a valve only on one side.] 



Spikes ovoid. Scales very numerous, finally deciduous. Flowers with a single valve, which 

 is situated opposite the scale, and is sometimes adherent to the fruit. Stamen single. Style 

 2-cleft. Achenium oblong, biconvex or nearly terete. — Spikes very dense, solitary or several 

 and aggregated, lateral. 



1. Hemicarpha subsquarrosa, Nees. Dwarf Hemicarpha. 



Culms setaceous, compressed and sulcate ; involucre 2-leaved, very long, unequal ; spikes 

 2-3, ovoid, sessile, lateral ; scales rhombic-obovate, with a short mucronate recurved point ; 

 achenium obovate-oblong, somewhat compressed. — Nees, Cyp. in Endl. 4- Mart. fl. Bras. 

 p. 61. t.A.f 1. Isolepis subsquarrosa, Schrad. in Schult. mant. 2. p. 64 ; Torr, Cyp. p. 348. 

 I. micrantha, Kunth, enum. 2. p. 203 (in part). Scirpus subsquarrosus, Muhl. gram. p. 39 ; 

 Torr. fl. 1. p. 51. S. minimus, Pursh, fl. 1. p. 53 (excl. syn.); Ell. sk. 1. p. 82. 



Annual. Culms in dense tufts, commonly about two inches high, leafy at the base. Leaves 

 setaceous. Involucre of 2 leaves : one of them short ; the other much longer, and setaceous. 

 Spikes sometimes solitary, about 2 lines long, closely sessile. Scales very numerous, some- 

 what coriaceous. Valve of the perigynium very thin, lanceolate or cuneate, often bifid, finally 

 adhering to the achenium. Stamen solitary. Style shorter than the achenium, simple at the 

 base ; the divisions recurved. Achenium obtuse, nearly terete, pale brown, smooth and dull, 

 mucronulate. 



Sandy shores of rivers and lakes in the northern and western parts of the State. Fl. July. 

 Fr. August. The valve of the perigynium is so very thin and delicate, that it may easily be 

 overlooked. 



