SEDGE FAMILY. 83 



Stem triquetrous or wing-angled, leafless or with a single short leaf at base; involucral 



bract 1 in. or less long; spikelets densely clustered 4. S. olneyi. 



Stem triangular, somewhat leafy; involucral bract 1 to 4 in. long; spikelets densely 



clustered 5.5. amcricanus. 



Inflorescence terminal; involucre of several spreading, foliaceous bracts. 



Spikelets 5 to 8 lines long, few, sparingly umbellate or in a sessile cluster, dark 



brown 6. .V. robustus. 



Spikelets 1 '/> to 2 lines long, numerous, in a compound or decompound panicle, 



greenish or lead-colored 7. S. murocarpus. 



1. S. riparius Spreng. Slender Club-rush. Annual; stems tufted, very 

 slender, 2 to 6 in. high, sheathed at base; upper sheath often bearing a short 

 slender leaf; involucral bract 1 to 3 lines long; spikelet solitary, oblong-ovate, 

 I 1 .' to 2% lines long, most less than 1 line wide; bractlets obtuse or mucronate; 

 bristles obsolete; achene less than % line long, trigonous-obovoid with distinct 

 angles, apiculate. not striate nor ribbed, dark brown when mature. 



Not uncommon in springy places: San Francisco; Olema. June- Aug. 



2. S. carinatus Gray. Dwarf Club-rush. Annual; stems slender, tri- 

 angular. 1 to 4 in. high, with a short leaf at base; involucral bract 5 to 6 

 lines long; spikelet solitary, ovate, 2 to 3 lines long, mostly 1% lines wide; 

 bractlet acute, shortly beaked, strongly keeled; bristles obsolete. 



About San Francisco, Bolancler; Santa Eosa Creek, Bigeloiu. 



3. S. lacustris L. var. occidentalis Wats. Tule. Perennial; roptstock 

 stout, creeping; stems 3 to 9 ft. high, terete or very obtusely trigonous above, 

 leafless or with a short terete leaf from the upper basal sheath; inflorescence 

 apparently lateral, umbellate, 4 to 5 in. long; involucral bract stout, shorter 

 than the inflorescence; spikelets 3 lines long, numerous, in an irregularly com- 

 pressed umbel; rays unequal; bristles 4 to 6, slender, retrosely barbellate, not 

 exserted; style 2-fid; achene gray, abruptly mucronate. 



Common in brackish and fresh-water marshes throughout the State: Lake 

 Merced; Martinez; Suisun Marshes, etc. The closely allied species S. calif or- 

 nicus (C. A. Mey.) Britt., (S. tatora Kunth), having the bristles shortly 

 plumose below and with a nearly white achene, narrowed above, should be 

 looked for. 



4. S. olneyi Gray. Olxey's Bulrush. Perennial; stems 2 to 5 ft. high 

 or more, stout, triquetrous, continued as an entire involucre about 1 in. or less 

 beyond the inflorescence, sheathed at base, leafless or with a single short, 

 triquetrous leaf; inflorescence apparently lateral; spikelets 2 to many in a 

 crowded sessile cluster, oblong-ovate, about 2 lines long; bractlets brown. 



Common in brackish marshes from Suisun Bay southward to Newark. May. 



5. S. americanus Pers. Three Square. Perennial; stems 1 to 2 ft high, 

 slender, triangular, somewhat leafy, continued as an entire, triangular, pungent 

 involucre 1 to 4 in. beyond the inflorescence; leaves short; inflorescence ap- 

 parently lateral ; spikelets 1 to 6, in a crowded, sessile cluster, oblong-ovate, 3 

 to 4 lines long; bractlets dark brown, usually conspicuously tipped with a 

 stout, pale-colored awn about a line long. — (S. pungens Vahl.) 



Marshy places, often brackish: San Francisco, southward and eastward. 



6. S. robustus Pursh. Salt-marsh Bulrush. Perennial; rootstock stout, 

 often forming hard woody tubers; Btems 1 to '■'< ft. high, stout, trigonous; 



- equaling or exceeding the stem, keeled, flat oi deeply channeled, 2 to 4 

 lines wide, antrorsely scabrid on the margins and keel; involucre of several 

 unequal spreading foliaceous bracts 1 to 8 in. long, one much the longer and 

 more erect; inflorescence terminal, of few to many sparingly umbellate spike- 

 etsj spike! - »blong-ovate, acute. 6 to s lines long, 4 to 5 lines broad at base, 



