3'4 



CYPERACEAE. 



VOL. I. 



10. Eleocharis Engelmanni Steud. Engelmann's Spike-rush. Fig. 767. 



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

 Eleocharis ovata var. Engelmanni Britton, Journ. N. Y. 



Micros. Soc. 5: 103. 1889. 

 E. tnonticola Fernald, Proc. Am. Acad. 34: 496. 1899. 



Annual, similar to the preceding species, but culms 

 commonly taller, sometimes 18' high. Upper sheath 

 obliquely truncate or i-toothed ; spikelet oblong- 

 cylindric or ovoid-cylindric, obtuse or subacute, 2"-8" 

 long, i"-ii" in diameter, many-flowered; scales pale 

 brown with a green midvein and narrow scarious 

 margin, ovate, obtuse, deciduous ; style 2-cleft ; bristles 

 about 6, not longer than -the achene, or wanting; achene 

 broadly obovate, brown, smooth, lenticular; tubercle 

 broad, low, covering the top of the achene. 



In wet soil, Massachusetts to Indiana, South Dakota, 

 Washington, New Jersey, Texas and California. July-Sept. 



ii. Eleocharis macrostachya Britton. Pale 

 Spike-rush. Fig. 768. 



E. macrostachya Britton; Small, Fl. SE. U. S. 184. 

 1903. 



Perennial by rootstocks, pale green. Culms 

 tufted, rather stout, sometimes twisted, 4 high 

 or less; spikelet lanceolate-cylindric, about i" 

 long or less, acute, many-flowered ; scales oblong- 

 ovate to oblong-lanceolate, acute, light green to 

 straw-color, with a somewhat darker midvein; 

 bristles as long as the achene and tubercle, or 

 shorter, sometimes very short ; style 2-cleft ; 

 achene obovate, lenticular, 1.5 mm. long, brown, 

 the cap-like tubercle small, yellow. 



In wet soil, Missouri to Louisiana, Nevada, Cali- 

 fornia and Jalisco. Aug.-Sept. 



12. Eleocharis palustris (L.) R. & S. Creeping Spike-rush. Fig. 769. 



Scirpns palustris L. Sp. PL 47. 1753. 

 Eleocharis palustris R. & S. Syst. 2: 151. 1817. 

 Eleocharis palustris var. vigens Bailey ; Britton, Journ. 



N. Y. Micros. Soc. 5: 104. 1889. 

 E. glaucescens Willd. Enum. 76. 1809. 



Perennial by horizontal rootstocks, culms stout or 

 slender, terete or somewhat compressed, striate, i*-5 

 tall. Basal sheaths brown, rarely bearing a short blade, 

 the upper one obliquely truncate ; spikelet oblong to 

 ovoid-cylindric, 3"-i2" long, \\"-2." in diameter, many- 

 flowered, thicker than the culm ; scales ovate-oblong or 

 ovate-lanceolate, purplish-brown with scarious margin 

 and a green midvein, or pale green all over; bristles 

 usually 4, slender, retrorsely barbed, longer* than the 

 achene and tubercle, sometimes wanting; stamens 2-3;' 

 style 2-3-cleft; achene lenticular, smooth, yellow, over 

 \" long; tubercle conic-triangular, constricted at the 

 base, flattened, one- fourth to one-half as long as the 

 achene. 



In ponds, swamps and marshes, Labrador to British Co- 

 lumbia, south to Florida, Texas and California. The spe- 

 cies consists of many races, the culms slender to stout, the tubercle narrow or quite broad. Also 

 in Europe and Asia. Aglet-headed rush. Aug.-Sept. 



