472 PROCEEDINGS OF THE AMERICAN ACADEMY. 



* * Mature perigynia distinctly more than one-third (.44 to .75) as broad 



as long. 



•*- Perigynia one-fifth to one-third (.19 to .34) as thick as broad (rarely 



thicker in C. mirabilis). 



++ Mature perigynia 3 to 4 mm. long (very rarely longer in C. mirabilis and 



C. albolutescens). 



— Mature perigynia with roseate-spreading tips. 



8. C. CRISTATA, Schweinitz. — Figs. 19 to 21. — Culms 1 m. or less 

 high, harsh above : leaves soft and flat, 3 to 7 mm. broad, often equalling 

 the culms, sheaths loose : spike usually dense, linear-cylindric or oblong, 

 of 6 to 15 globose closely flowered greenish or dull-brown spikelets 0.5 to 

 1 cm. long. — Ann. Lye. N. Y. i. 66 ; Schwein. & Torr. Ann. Lye. 

 N. Y. i. 315, t. 24, fig. 1 ; Dewey, 1. c. 44 ; Boott, 1. c. 117, in part ; 

 Gray, Man. ed. 5, 579; Boeckeler, 1. c. 115; Howe, 1. c. 41. C. 

 lagopodioides, var. cristata, Carey, 1. c. 545. C straminea, var. cristata, 

 Tuck. 1. c. 9, 18. C tribuloides, var. cristata, Bailey, Proc. Am. Acad, 

 xxii. 148, in Gray, Man. ed. 6, 620, & Mem. Torr. CI. i. 55 ; Macoun, 

 1. c. 130. C. cristatelbi, Britton, 1. c. 357, fig. 865. — Swales and wet 

 woods, western New England to Pennsylvania, " Virginia/' Mis- 

 souri, Saskatchewan, and British Columbia. June-Aug. 



= = Mature perigynia with ascending tips. 



a. Plant stout and stiff: spikes stiff and upright ; the gray-green mostly approx- 

 imate spikelets with appressed firm perigynia. 



9. C. albolutescens, Schweinitz. — Figs. 22 to 24. — Culms 2 to 8 

 dm. high : leaves erect, long-pointed, pale green, 2 to 5 mm. wide, 

 shorter than the culms : spike linear-cylindric to subglobose, with or 

 without elongated bracts, of 3 to 30 (sometimes compound) conic-ovoid 

 to subglobose spikelets 0.6 to 1 cm. long : perigynia 2 to 3 mm. broad, 

 rhombic-ovate to suborbicular, with a short deltoid firm greenish tip. — 

 Ann. Lye. N. Y. i. 66; Bailey, Bull. Torr. CI. xx. 422 (incl. var. 

 cumulata) ; Britton, 1. c. 359, fig. 873; Howe, 1. c. 43. C. foenea, 

 Ell. Sk. ii. 533 ; Schwein. & Torr. 1. c. 315 ; Carey, 1. c. 546; Boott, 

 1. c. 118 (excl. vars.), t. 375; not Willd. C. straminea, var. foenea, 

 Torr. Ann. Lye. N. Y. iii. 395 ; Bailey, Proc. Am. Acad. xxii. 150, 

 & in Gray, Man. ed. 6, 622 ; Macoun, 1. c. 132. C. straminea, var. 

 intermedia, Gay, Ann. Sci. Nat, ser. 2, x. 364. C. leporina, var. 

 bracteata, Liebmami, Mex. Halv. 76. C. straminea, var. chlorostachys, 

 Boeckeler, 1. c. 118. 0. straminea, var. cumulata, Bailey, Mem. Torr. 



