194 CYPERACEAE 





2. ELEOCHARIS R. BR. SPIKE-RUSH. 



Annuals or chiefly perennials. Stems tufted, simple, terminating in a solitary 

 spikelet not subtended by an involucre. Leaves reduced to sheaths or the lowest 

 rarely blade-bearing. Spikelets several to many-flowered. Scales concave. 

 Stamens 2 or 3. Perianth-bristles 3 to 9, commonly retrorsely barbed. Style 

 3-eleft and achene 3-angled, or 2-cleft and achene lenticular; base of the style 

 enlarged and persistent as a tubercle on the summit of the achene. Species 127, 

 widely distributed from the arctic to antarctic regions. (Greek elos, marsh, and 

 charis, delight.) 



Bibliog. Fernald, M. L., Eleocharis ovata and its N. Am. Allies (Proe. Am. Acad. 34:485- 

 497, 1899). 



Style mostly 2-cleft; aehene lenticular or biconvex. 



Achene jet-black; tubercle depressed; annual _ 1. E. capitata. 



Achene light-brown. 



Perennial; tubercle conical, less than half as broad as the body of the achene; spikelet 



lanceolate _ 2. E. palustris. 



Annual; tubercle thin, deltoid, as broad or nearly as broad as the achene; spikelet ovate. 



Bristles often nearly twice as long as the achene 3. E. obtu-sa. 



Bristles a /4 to % as long as the achene 4. E. monticola. 



Style 3-cleft; achene turgid or 3-angled; perennial. 



Tubercle reduced to a mere scar or very obscure i 5. E. bolanderi. 



Tubercle well-developed and more or less prominent. 



Achene with several longitudinal ridges connected by a transverse lattice-work; spikelet 



flattened 6. E. acicularis. 



Achene smooth. 



Stems erect or nearly so, not rooting at tip; tubercle constricted at base or at least 

 sharply defined from the achene. 



Spikelet lanceolate; scales acute 7. E. paris/iu. 



Spikelet oblong; scales obtuse _ 8. E. montana. 



Stems or some of them bending over and rooting at tip; tubercle subulate or nar- 

 rowly pyramidal, continuous with the achene 9. E. rostellata. 



1. E. capitata R. Br. Stems erect, tufted, 7 to 8 inches high ; spikelet ovate, 

 li/4 to 2 lines long; bristles 6 (or 7), about as long as the achene; stamens 2 or 3 ; 

 achene black and shining, lenticular; tubercle white, thin and a little like a 

 skull-cap. 



Wet sandy soil, Southern California. Eastern United States, Asia, Africa, 

 Australia. 



Locs. Warm Creek, San Bernardino, Parish; Palm Sprs., ace. Parish; Thousand Palms 

 Canon, Riverside Co., Jepson 6043 ; Dos Palmas, Hall 5984. 



Eef. ELEOCHARIS CAPITATA R. Br. Prodr. FL Nov. Holl. 1:225 (1810), types from Virginia 

 and the Caribbees. 



E. ATROPURPUREA Kunth, Enum. PL 2:151 (1837). Scirpus atropurpureus Retz. Obs. 5:14 

 (1789), type loc. India. Near E. capitata; scales minute; bristles 2 to 4, white, or wanting; 

 achene jet-black, lenticular; tubercle conic, minute, depressed. Visalia (ace. Coville, Contrib. 

 U. S. Nat. Herb. 4:211). Widely distributed, oecuring in the eastern United States and in 

 all continents. 



2. E. palustris R. & S. COMMON SPIKE-RUSH. WIRE-GRASS. (Fig. 14.) 

 Stems Vo to 2 feet high, stoutish, mostly terete, sheathed at the base, leafless, 

 creeping, stoloniferous ; sheaths sub-truncate ; rootstock stout ; spikelet many- 

 flowered, 6 to 14 lines long ; bracts ovate-oblong to oblong-lanceolate ; scales ovate- 

 oblong, purplish brown with scarious margin ; bristles 3, rather shorter than the 

 achene; style 2-cleft; achene obovoid, biconvex; tubercle deltoid, constricted at 

 the point of junction. 



Ponds, marshes and shallow slow-moving creeks, at low altitudes in California 

 North to British Columbia and east to the Atlantic. Europe, Asia. 



