CYPERACEAE. 65 



4. FIMBRISTYLIS Vahl. 



Annual or perennial herbs with stems leafy below. 

 Spikelets umbellate, several-many-flowered, subtended 

 by a 1-many-leaved involucre, their scales spirally imbri- 

 cated, mostly deciduous, all fertile. Perianth none. 

 Stamens 1-3. Style 2-3-cleft, pubescent or glabrous, its 

 base much enlarged, falling away from the achene when 

 mature. Achene lenticular, biconvex or 3-angled. 



1. F. thermalis Wats. Perennial by short matted rootstocks; 

 stems 3-6 dm. high, flattened and somewhat roughened, striate; 

 leaves 2-4 mm. wide, flat, becoming more or less revolute, some- 

 what pubescent or nearly glabrous, rough on the margins; involucral 

 bracts linear-subulate, acuminate, scabrous, 15-25 mm, long, shorter 

 than the rays; spikelets umbellate, solitary on the ends of the rays, 

 ovate to linear-oblong, 8-18 mm. long; scales ovate, obtuse, mucro- 

 nate, dull brown, pubescent; style 2-cleft, flattened and ciliate; 

 achene obovate, lenticular, obscurely striate, 1.5 mm. long; tubercle 

 soon deciduous. 



Hot Springs, near San Bernardino, Wright; Waterman's Hot 

 Springs, Parish. 



5. SCHOENUS L. 



Ours perennial herbs from rootstocks, with slender 

 erect tufted stems and slender subterete basal leaves. 

 Involucral bract erect, appearing as a continuation of the 

 stem. Spikelets sessile in capitate lateral clusters, few- 

 flowered. Scales imbricated in 2 rows, the lower ones 

 empty, the upper bearing perfect flowers. Perianth of 6 

 scabrous or pubescent bristles. Stamens 3. Style 3- 

 cleft, not dilated at the base. Achene more or less 3- 

 angled, with a very short beak. 



1. S. nigricans L. Stems tufted, slightly compressed, slender, 

 5-7 dm. high; leaves rigid, subterete, channeled, rough on the mar- 

 gins, shorter than the stems; sheaths black; involucral bract 3-5 

 cm. long; spikelets capitate clustered, ovate lanceolate, compressed, 

 6-8-flowered; rachis zigzag; scales ovate, acute, compressed, keeled, 

 very dark brown; bristles 6, unequal, dilated at the base, barbed 

 above, longer than the achene; achenes globose-oblong, 3-angled, 

 white and shining. 



Arrowhead Hot Springs, near San Bernardino, Parish. Other- 

 wise known in North America only from Florida. 



6. CLADIUM R. Br. 



Perennial herbs with stout rootstocks, stout tall leafy 

 stems and elongated channeled leaves. Spikelets small, 



