SEDGE FAMILY 111 



spikelets qvoid-oblong, obtuse, 3-10 mm. long; glumes ovate or lanceolate, acute 

 or subacute. Swamps: Ne^\'f. — Fla. — La. — Sask. Plain. Au-S. 



19. S. atrocinctus Fernald. Stem 5-12 dm. high, smooth, terete; leaves 

 bright green, 2-5 mm. wide; bracts blackish at the base; spikelets 2.5-6 mm. 

 long; glumes lance-ovate, acute; achenes 3-angled, white, ovate. Swamps: 

 Newi.— N.J.— la.— B.C. Submont.—Mo?it. Je-Au. 



10. HEMICARPHA Nees & Arn. 



Dwarf annual tufted herbs. Leaves narrow, often setaceous. Spikelets 

 terete, solitary or in small clusters. Glumes spirally arranged. Flowers per- 

 fect, each with a small translucent scale between it and the axis. Perianth want- 

 ing, i. e., bristles none. Stamen 1. Style 2-cleft, not swollen at the base. 



1. H. aristulata (Coville) Smyth. Stem longer than the setaceous glabrous 

 leaves, 5-20 cm. high; bracts 1-3, sometimes 2 cm. long; spikelets 4-8 mm. 

 long; glumes rhombic-obovate, bro^\^l, abruptly contracted into a subulate awn 

 about as long as the bodj'; achenes narrowly obovate, black. H. intermedia 

 Piper. Sandy banks: Kans. — -Te.x. — -Calif. — -Wash. Son. — -Submont. Jl-S. 



11. KOBRESIA Willd. 



Sedge-like perennials, with monoecious flowers. Spikelets several-flowered, 

 forming a terminal spike. Glumes spirally arranged, the lower usually enclos- 

 ing a pistillate, the upper a staminate flower. Stamens 3. Perianth lacking. 

 Style short; stigmas 3. Achenes obtusely 3-angled. 



1. K. bipartita (All.) Delia Torre. Stems solitary or tufted, 1-3 dm. high, 

 smooth; leaves about 1 mm. wide, involute; spikets several in a spike, ascending, 

 Unear; glumes somewhat serrulate on the keel, fully 1 mm. long. K. caricina 

 Willd. Ai'ctic-alpine situations: Greenl. — -Alta. — B.C. Alp. Je-S. 



12. ELYNA Schrad. 



Low, tufted, sedge-like monoecious plants. Leaves mostly basal, narrow. 

 Spikelets 2-flowered, forming a terminal spike. Glumes of the spikelets 3 or 4, 

 usually only one flower-bearing. Flowers 2, one staminate of 3 stamens, the 

 other pistillate with a single pistil. Perianth none. Style slender, not jointed 

 to the ovary; stigmas 3. Achenes obtuselj' 3-angled. 



1. E. Bellardi (All.) C. Koch. Densely tufted; stems slender, 1-4 dm. high; 

 old sheaths fibrillose, brown; leaf -blades revolute; spikelet subtended by a short 

 bract or bractless, 15-30 mm. long, 3-4 mm. wide; achenes appressed, ellipsoid, 

 2 mm. long or less. Arctic-alpine situations: Greenl. — Alta. — -n N.M.^ — Ore. — 

 Alaska; Eurasia. Alp. Je-Au. 



13. CAREX (Rupp.) L. Sedge.* 



Grass-like sedges, perennial by rootstocks. Culms mostly triangular, often 

 strongly phyllopodic or aphyllopodic. Leaves 3-ranked, the upper (bracts) 

 elongate or short, and subtending the spikes of flowers or wanting. Plants 

 monoecious or sometimes dioecious; flowers solitary in the axils of scales (glumes). 

 Spikes one to many, either wholly pistillate, wholly staminate, androgynous or 

 gynaecandrous. Perianth none. Staminate flowers of three (or rarely two) 

 stamens, the filaments filiform. Pistillate flowers of a single pistil, with a style 

 and two or three stigmas. Achene completely surrounded by the perigynium, 

 or rarely rui^turing it in ripening, 3-angled, lenticular or plano-convex. Rhacheola 

 occasionalh' developed. 



Spike one, androgjTious ; perigjTiia glabrous, thin, not margined or triangular, beaked; 

 style withering, not continuous with the achene; stigmas three. 

 Pistillate scales oersistent; perigynia not stipitate. not becoming reflexed. 

 Spike linear or linear-oblong : perigynia not inflated. 1. N.'iHDiNAE. 



Spike orbicular to short-ovoid; perigjToia inflated. 2. Infi^\t,\e. 



Pistillate scales deciduous; perigjTiia stipitate, at least the lower refle.xed at maturity. 



3. Athrochl.\enae. 



* Contributed by Mr. Kenneth K. Mackenzie. 



