MONOCOTYLEDOKOUS Oil ENDOGENOUS PLANTS. 679 



ELEOCHARIS, R. Br. Spike-rush. 



Spihes many- (rarely 2-4) -flowered; scales imbricated 

 on all sides of the rachis, or somewhat 2-ranked, the lowest 

 usually empty, bract-like, and persistent ; perianth of 3-8 

 bearded bristles, occasionally wanting ; stamens 1-3 ; style 

 2-3-cleft ; nut compressed, biconvex, or 3-angled, crowned 

 with the persistent jointed base of the style (tubercled). 

 Commonly perennials, with creeping rootstocks. Culms 

 jointless, leafless, sheathed at the base, bearing at the apex 

 a single spike. 



§ 1. Eleochakis proper. Spikes many-flowered ; scales imbricated in several rows. 



* Spikes cylindrical, scarcely thicker than the soft cellular culms ; nut biconvex, pitted or 

 wrinkled in longitudinal lines. 



t Scales rounded, thick and faintly nerved ; style 3 cleft ; bristles 6, sparingly bearded 

 or smoothish, as long as the nut. (Limnochloa, Nees.) 



E. EQUiSETOiDES, Torr. Culms stout, terete, knotted by 

 cross partitions, roughisli ; scales pale, round-ovate, obtuse 

 or the upper acute, scarious on the margins ; bristles hispid ; 

 nut pale brown, obscurely wrinkled, shining, crowned with 

 a sessile conical-beaked acute tubercle. (Scirpus eqiiise- 

 toides. Ell.) Ponds. July-September. Culms l°-2° high, 

 3" in diameter; sheaths brown ; spikes V long. Perennial. 



E. QUADRANGULATA, R Br. Cuhus Unequally 4-sided, 

 with the angles acute ; scales pale, roundish, very obtuse, 

 scarious on the margins ; bristles slender, bearded, unequal ; 

 nut broadly obovate, finely pitted, dull white; tubercle 

 ovate or conical, free around the base, much shorter than 

 the nut. (Scirpus quadrangulatus, Michx.) Ponds and 

 ditches. July-September. Culm 2°-3° high, l"-2" in 

 diameter ; sheaths purplish ; spikes 1' long. Perennial. 



** Spikes thicker than the culm ; style Z-cleft ; nut Z-angled. 

 t Bristles 6, as long as the nut and tubercle ; nut longitudinally furrowed and pitted. 



E. TUBERCULOSA, R. Br. Culms somewhat compressed, 

 tough and wiry; spikes pale, ovate or oblong, acute; 



