3 12 



CYPERACEAE. 



Vol. I. 



4. Eleocharis flaccida (Rchb.) Urban. Pale Spike-rush. Fig. 761. 



Scirpus flaccidus Rchb. ; Spreng. Tent. Suppl. 3 : 1828. 

 Eleogenus ochreatus Nees, in Mart. Fl. Bras. 2 : Part 1, 102. 



1842. 

 Eleocharis ochreata Steud. Syn. PI. Cyp. 79. 1855. 

 Eleocharis flaccida Urban, Symb. Ant. 2 : 165. 1900. 



Perennial by very slender rootstocks, culms very 



slender, or filiform, erect, pale green, 3-angled, 2'-io' 



tall. Upper sheath with a white, hyaline, scarious 



limb; spikelet oblong or ovoid, subacute, 2-3 times as 



thick as the culm, about 2" long, il" in diameter, 



several-flowered; scales pale green, oblong-lanceolate, 



obtuse or the upper acute, thin, hyaline with a faint 



midvein; style 2-cleft; bristles about 6, slender, re- 



trorsely barbed, as long as or somewhat longer than 



the achene, or wanting; achene i" long, lenticular, obo- 



vate, smooth, brown, 2-4 times as long as the conic 



acute tubercle, which is often constricted at the base. 



In wet soil, New Jersey and Delaware to Florida and Mis- 

 sissippi. Also in tropical America. Aug.-Sept. 



5. Eleocharis olivacea Torr. Bright green Spike-rush. Fig. 762. 



Eleocharis olivacea Torr. Ann. Lye. N. Y. 3 : 300. 1836. 



Perennial by running rootstocks, often tufted and 

 matted, culms very slender, bright green, erect or re- 

 clining, flattened, i'-4' long. Upper sheath with a 

 white hyaline limb ; spikelet ovoid, acute or obtuse, 

 much thicker than the culm, several-many-flowered, 

 about 2" long, 1" in diameter; scales ovate, thin, acute, 

 reddish-brown, with a green midvein and narrow, 

 scarious margins ; stamens 3 ; style 2-cleft ; bristles 6-8, 

 slender, retrorsely barbed, longer than the achene and 

 tubercle ; achene obovoid, similar to that of the pre- 

 ceding species but twice as large, 3-4 times the length 

 of the conic acute tubercle. 



In wet soil, Maine to southern Ontario, Michigan, Penn- 

 sylvania, South Carolina and Kansas. Aug.-Sept. 



6. Eleocharis atropurpurea (Retz) Kunth. Purple Spike-rush. Fig. 763. 



Scirpus atropurpureus Retz, Obs. 5: 14. 1789. 



Eleocharis atropurpurea Kunth, Enum. 2: 151. 1837. 



Annual, roots fibrous, culms tufted, very slender, 

 i'-3i' high. Upper sheath i-toothed; spikelet ovoid, 

 many-flowered, subacute, ii"-2" long, 1" in diameter or 

 less; scales minute, ovate-oblong, obtuse or the upper 

 acute, persistent, purple-brown with green midvein and 

 very narrow scarious margins; stamens 2 or 3; style 

 2-3-cleft; bristles 2-4, fragile, white, minutely down- 

 wardly hispid, about as long as the achene; achene jet 

 black, shining, i" long, smooth, lenticular; tubercle 

 conic, minute, depressed but rather acute, constricted . 

 at the base. 



In moist soil, Nebraska and eastern Colorado to Central 

 America, east to Iowa and Florida ; widely distributed in 

 tropical America, Europe and Asia. July-Sept. 



