I 



CYPERACE.E. (SEDGK FAMILY.) 557 



1. H. SUbsquarrdsa, Nccs. Dwarf or minute annual (l'-5' high); 

 invohicre l-lcavud, as if a continuation of tiie bristle-like cuhn, and usually with 

 another n)inute leaf; spikes 2-3 (barely 2" long) ; scales brown, tip])ed with a 

 short recurved point. (Scirpus subsquarrosus, Muhl.) — Sandy borders of 

 ponds and rivers; often growing with Cyperus inflexus. July-Sc])t. — Var. 

 Drummondii (H. Drummondii, Nees.) is a form with single and paler or green- 

 ish heads : Illinois and southward. 



7. ELEOCHARIS, R.Br. SpiKii-Rusii. (PI. 3.) 



Spike single, terminating the naked culm, many -several-flowered. Scales 

 imbricated all round in many (rarely in 2 or 3) ranks. Perianth of 3 - 12 (com- 

 monly 6) bristles, usually rough or barbed downwards, rarely obsolete. Sta- 

 mens 3. Style 2-3-cleft, its bulbous base persistent as a tubercle, which is 

 jointed with the apex of the lenticular or triangular achenium. — Leafless, 

 chiefly perennial, with tufted culms sheathed at the base, from matted or creep- 

 ing rootstocks : flowering in summer. (Name from eXos, a marsh, and x^'P"' 

 to de/iglit in; being marsh plants.) 



§ 1. Spike terete, hirdhj if at all thicker than the spongi/-cel!u!ar culm ; the scales 

 Jirmltf jiersistent : sti/le mostly 3-(J(ft : bristles of the perianth 6 [rarehj l),Jinn 

 or rigid, mostly bailed downwardly, and equalling or surpassing the triangular or 

 double convex achenium. 



* Spike linear or lanceolate-aid-siiaped, few-Jlower<d ; the scales {only 3 - 9) few- 



ranked, convolute-clasjiing the long flattened joints of the axis, lanceolate, herba- 

 ceous (green) and several-nerved on the back, and with thin scniioits margins. 



1. E. Robbinsii, Oakes. Flower-bearing culms exactly triangular, rather 

 stout, erect (8'- 2° high), also producing tufts of capillary abortive stems or 

 fine leaves, which float in the water; sheath obliquely truncate; achenium ob- 

 long-obovate, triangular, minutely reticulated, about half the length of the 

 bristles, tipped with a flattened awl-shaped tubercle. — Shallow water; from 

 Pondicherry Pond, New Hampshire (Bobbins), to New Jersey (C. E. Smith, 

 ^~c.), and southward. — Spike varying from 4" to 10'" long, by scarcely over a 

 line wide ; the long scales rather remote and sheath-like. 



# * Spike cylindrical and many-flowe>-ed, 1 ' - 2' long ; the scales regulai-ly imbricated 



in several ranks, flrm-coriaceous with a narrow scarlous margin and no midrib, 

 pale, nerveless or faintly striate : culms large and stout (2° - 4° high) : sheat/is at 

 the base of en leaf-bearing. (Limnochloa, Nees.) 



2. E. equisetoldes, Torr. Culm terete, knotted as if jointed by many cross 

 partitions; achenium smooth, with a conical-beaked tubercle. — Shallow water, 

 Rhode Island (OIney), Michigan (Houghton). Delaware, and southward. 



3. E. quadrangulata, R. Br. Culm continuous and sharply 4-angUd ; 

 achenium flnely reticulated, with a conical flattened distinct tubercle. — Shallow 

 water, New York (outlet of Oneida Lake, A. II. Curtiss) to Michigan and 

 southward : rare. 



§ 2. Spike terete and turgid-ovate, very much thicker than the slender culm ; the scalet 

 thiri-coriaceous or firm-membranaceous and persistent, ovale: style 3-clefl : bristles 



