SEDGE FA:\IILY 



271 



3. Scirpus cernuus Vahl. 

 Low Club-rush. Fig. 648. 



Scirpiis cernuus Vahl, Enum. 2: 245. 1806. 

 Scirpus riparius Spreng. Syst. 1: 208. 1825. 

 Isolepis pygmaea Kunth, Enum. 2: 191. 1837. 

 Scirpus leptocaulis Torr. Bot. Whipple E.xp. 97. 1857. 

 Scirpits pygmaeus A. Gray, Proc. Am. Acad. 7: 392. 1868. 

 Isolepis pygmaea californica Torr. Bot. Wilkes Exp. 476. 1874. 



Annual, with fibrous roots ; culms nearly filiform, tufted. 5-25 

 cm. long, the upper sheath bearing a filiform leaf 2-20 mm. long, 

 or merely acuminate. Spikelet solitary, ovoid, 2-5 mm. long, few- 

 flowered, subtended by a bract 2-20 mm. long; scales broadly 

 ovate, pale to dark brown, concave, scarcely keeled, obtuse or 

 acutish; bristles none; style 3-cleft; nutlet sharply trigonous, 

 smooth, brown, somewhat less than 2 mm. long. 



Moist or wet ground, Sonoran and Transition Zones; Lower California 

 to British Columbia; western South America; Australia. Widely distrib- 

 uted in the Old World. Type locality: Lusitania. 



4. Scirpus pauciflorus Lightf. 



Few-flowered Club-rush. 



Fig. 



649. 



Scirpus pauciflorus Lightf. Fl. Scot. 1078. 1777. 

 Eleocharis pauciflora Link, Hort. Berol. 1: 284. 1827. 



Perennial by filiform rootstocks ; culms very slender, 

 little tufted, 3-angled, grooved, leafless, 7-25 cm. tall, the 

 upper sheath truncate. Spikelet terminal, solitary, not 

 subtended by an involucral bract, oblong, compressed, 

 4-10-flowered, 4-6 mm. long, nearly 2 mm. wide ; scales 

 brown with lighter margins and midvein, lanceolate, 

 acuminate ; bristles 2-6, hispid, as long as the achene or 

 longer, or wanting ; stamens 3 ; style 3-cleft ; achene 

 obovoid-oblong, gray, rather abruptly beaked, its sur- 

 face finely reticulated. 



Wet soil, Canadian Zone; San Bernardino County. California, 

 to British Columbia, east to Colorado, Ontario, New York, Maine, 

 and Anticosti. Europe. Type locality. Highlands of Scotland. 



5. Scirpus caespitosus L. 

 Tufted Club-rush. Fig. 650. 



Scirpus caespitosus L. Sp. PI. 48. 1753. 

 Eleocharis caespitosa Nees, Linnaea 9: 294. 1835. 



Perennial ; culms smooth, terete, densely tufted, 

 light green, erect or ascending, almost filiform, wiry, 

 10^0 cm. long. Basal sheaths numerous, membranous, 

 imbricated, acuminate, the upper one bearing a 

 short very narrow blade; spikelet solitary, terminal, 

 few-flowered, ovoid-oblong, about 4 mm. long, sub- 

 tended by a subulate involucral leaf of about its own 

 length ; scales yellowish brown, ovate, obtuse or sub- 

 acute, deciduous ; bristles 6, smooth, longer than the 

 achene ; stamens 3 ; style 3-cleft ; achene oblong, 

 smooth, 3-angled, brown, acute. 



In bogs and on moist rocks, Arctic Zone: Washington to 

 Alaska, east to Colorado, Minnesota, New York. Maine, and 

 Greenland and on the southern Alleghenies. Europe and 

 Asia. Type locality: Europe. 



