52 CYPERACEAE. 



5. ABILDGAARDIA Yahl, Ennm. 2: 296. 1806. 



Low, perennial or annual sedges, "witli slender culms, narrow or setaceous 

 basal leaves, the involucre usually of 1 small bract, the flattened spikelets soli- 

 tary or few together, several-many-flowered. Scaly imbricated in 2 rows, 

 keeled, deciduous. Bristles none. Stamens 1-3. Style pubescent, deciduous, 

 its base swollen. Stigmas 3. Achene trigonous. [Commemorates P. S. Abild- 

 gaard, Danish botanist.] About 15 species of tropical and subtropical dis- 

 tribution, the following typical. 



1. Abildgaardia monostachya (L.) Vahl, Enum. 2: 296. 1806. 



Cyperus monostachyos L. Mant. 180. 1771. 



Fimhristylis Tnonostachya Hassk. PI. Jav. Ear. 61. 1848. 



Perennial, glabrous; culms tufted, very slender, smooth, thickened at the 

 base, 1-4 dm. high. Leaves setaceous, 0.5 mm. wide, about half as long as the 

 culm; involucral bract short, rarely as long as the spikelet; spikelet ovate or 

 ovate-lanceolate, flat, 1-1.5 cm. long, about 5 mm. wide; scales ovate, keeled, 

 mucronate, pale greenish-brown with white margins; style villous, with 3 short 

 branches; achene obovoid, 2-2.5 mm, long, 3-angled, yellowish, tuberculate. 



Grassy places and scrub-lands, Great Bahama, Andros, New Providence, Cat 

 Island, Fortune Island, Inagua : — Florida ; Cuba to Porto Rico ; St. Jan to Tobago ; 

 Anegada ; continental tropical America and Old World tropics. Flat-spiked Rush. 



6. SCIRPUS L. Sp. PI. 47. 1753. 



Annual or perennial very small or very large sedges, with leafy culms or 

 the leaves reduced to basal sheaths. Spikelets terete or somoAvhat flattened, 

 solitary, capitate, spicate or umbellate, subtended by a 1-several-leaved in- 

 volucre or the involucre wanting in some species. Scales spirally imbricated 

 all around, usually all fertile, the 1-3 lower sometimes empty. Flowers per- 

 fect. Perianth of 1-6, slender or rigid, short or elongated, barbed, pubescent 

 or smooth bristles, or none in some species. Stamens 2-3. Style 2-3-cleft, not 

 swollen at the base, wholly deciduous from the achene, or its "base persistent 

 as a subulate tip. Achene triangular, lenticular or plano-convex, [Latin 

 name of the Bulrush, said to be from sirs, the Celtic word for rushes.] About 

 200 species of very wide geographic distribution. Type species: Scirpus 

 lacustris L. 



Bracts of the involucre several ; scales long-awned ; culm trigonous. 1. S, rohustvs. 

 Bract of the involucre only 1 ; scales short-tipped ; culm terete. 2, S. validits. 



1, Scirpus robustus Pursh, El, Am. Sept. 56. 1814. 



Perennial by rootstocks ; culm stout, stiff, 3-angled with flat sides, smooth, 

 0.5-1,4 m. tall. Leaves dark green, smooth, 5-10 mm, wide; involucral leaves 

 2-4, elongated, similar to the lower ones; spikelets ovoid-oblong, stout, 1,5-2.5 

 cm. long, 8-10 mm. in diameter, 6-20 together in a dense terminal cluster ; scales 

 ovate, brown, puberulent, thin, the midvein excurrent into an, at length, re- 

 flexed awn 3-5 mm. long; bristles 1-6, fragile, shorter than the achene, or none; 

 style 3-cleft; achene compressed, flat on the face, convex or with a low ridge 

 on the back, obovate-orbicular, dark brown, shining, 3 mm. long. 



Marshes, Little Inagua : — Atlantic and Gulf coasts of the United States. Salt 

 Mahsh Bulrush. 



