486 PEOCEEDINGS OF THE AMERICAN ACADEMY. 



•1- -4- Perigynia broadest near the middle, tapering to a narrow base and a 



smooth beak. 



29. C. SEORSA, E. C. Howe. — Figs. 106 to 109. — Culms soft, in 

 loose stools, 3.5 to 6.5 dm. high : leaves shorter, soft, pale, 2 to 4 mm. 

 broad : spikes 2,5 to 7 cm. long, oi 2 to 6 mostly remote subglobose or 

 oblong 6- to 20-flowered green spikelets 3.5 to 7 mm. long, the ter- 

 minal one usually with a long-clavate base, the lower often subtended 

 by a setiform bract : perigynia very thin and conspicuously nerved, ellip- 

 tic-ovate, with a very short smooth beak and a narrow suhstipitate base, 

 2.7 ram. long, 1.9 mm. broad, wide-spreading or recurved, much exceed- 

 ing the acutish scales. — 48 Rep. N. Y. Mus. Nat. Hist. 40. C. canes- 

 cens, var. vulgaris, Deane, Met. Park Fl. 95, not Bailey. — Wet woods 

 and swamps, from Middlesex Co., Massachusetts to Suffolk and 

 Oneida Cos., New York, south to Delaware. May, June. 



Elongatae, Kunth. Spikelets remote or approximate in a simple 

 elongated or short inflorescence. Staminate flowers at the base of the 

 spikelets. Perigynia ascending when mature, glabrous, ovate to oblong or 

 lanceolate, plano-convex, beaked or beakless, not thin-winged. 



* Perigynia more or less roughened or serrulate on the upper edges (sometimes 

 smooth in exceptional forms of C canescens ; and by exception obscurely toothed 

 in rare individuals of C. tenuiflora). 



■*- Perigynia broadest at the rounded or subcordate base. 



30. C. arcta, Boott. — Figs. 110 to 113. — Pale green or somewhat 

 glaucous : culms very soft, in loose stools, 1.5 to 6 dm. high, often over- 

 topped by the soft flat leaves 2.5 to If mm. broad: sjnke oblong -cylindric, 

 of 5 to 13 ovoid or oblong closely approximate or slightly remote spikelets 

 6 to 11 mm. long: perigynia ovate, with a rather definite beak, strongly 

 nerved on the outer, faintly on the inner face, 2 to 3 mm. long, 1.2 to 

 1.5 mm. broad, somewhat exceeding the acute, often brown-tinged, 

 scales. — 111. iv. 155, t. 497 ; Macoun, 1. c. 124 ; Britton, 1. c. 352, fig. 

 850. C. canescens, var. polystachya, Boott in Richards. Arct. Exped. ii. 

 344; Bailey, Proc. Am. Acad. xxii. 144, Mem. Torr. CI. i. 75, & in 

 Gray, Man. ed. 6, 619. C. Kunzei, Olney, Proc. Am. Acad. viii. 406 

 (excl. syn.). G. canescens, var. oregana, Bailey, Mem. Torr. CI. i. 75. 

 — "Wet woods, alluvial thickets and swales, from the larger river-valleys 

 of Maine and Quebec, Lake Champlain, Vermont, and the Adirondack 

 Mts., New York to Lake Nipigon, Ontario, and British Columbia, 

 south to Michigan, Minnesota, and the coast and mountains of 

 Washington and Oregon. June-Aug. 



