GRAMIXEiE. (GRASS FAMILY.) 615 



§1. DETEUXIA, Kuntli. Rudiment of a second flower present in the form of a 

 plumose or hairy small pedicel behind the upper pal et [very rarely more developed 

 and having palets or even stamens) : glumes and palels membranaceous, or the lat- 

 ter thin and delicate as in Agrostis ; the lower 3 - 5-nerved and awn-bearing. 



* Panicle loose and open, even after flowering : the mostly purple-tinged or lead-colored 



striijose-scttbrous (jlumes not closing in fruit : copious hairs surrounding the flower 

 about equalling the hyaline lower palet, not surpassed by those of the rudiment : 

 awn delicate, straight. 



1. C Canadensis, Beauv. (Blue Joint-Grass.) Culm tall (3°-5° 

 high) ; leaves flat when fresh, glaucous; panicle oblong; glumes ovate-lanceolate, 

 acute, 14," - 1 £" long ; awn from near the middle of the palet, not exceeding and 

 scarcely stouter than the hairs around the flower. (Arundo Canadensis, Michx. 

 C. Mexicana, Nutt.) — Wet grounds : common northward. July. 



2. C. Langsdorffii, Trin. Spikelets larger, 2^" -3" long; glumes lanceo- 

 late or oblong-lanceolate and gradually taper-pointed; awn stouter: otherwise like 

 the preceding. — White Mountains, New Hampshire, and northward. (Eu.) 



* * Panicle strict, its short branches oppressed or erect after flowering, and the glumes 



mostly closed: lower palet less delicate, roughish, sometimes of asflrm texture as 

 the glumes : awn stouter. 



■*- leaves narrow, inclined to be involute: awn straight. 



3. C. Strieta, Trin. Panicle glomerate and lobed, strict ; glumes 1 J" -2" 

 long, ovate-oblong, not acuminate; hairs scarcely or little shorter than the 

 flower, and as long as those of the rudiment ; awn from the middle of the thin 

 palea or lower, and barely exceeding it. — Ledges at Willoughby Lake, Vermont 

 ( W. Boott), Lake Superior, and northward. (Eu.) 



■*- +- Leaves broader, flat : awn stoutei; bent, divergent, or twisted when dry. 



4. C. COnfinis, Nutt. Panicle elongated, its rather slender branches spread- 

 ing at flowering-time, afterwards appressed ; glumes lance-oblong, very acute, 

 2" long, pale; hairs of the flower copious, equal, slightly or one third shorter than 

 the thin lower palet and than those of the rudiment ; awn borne much below the 

 middle of the palet, somewhat surpassing it ; grain glabrous. (Arundo confinis, 

 Willd.'. C. iriexpahsa, Gray.) — Swamps, N. and W. New York (especially 



Penn Yan, Swrtwell) and Pennsylvania. July. — Culm tall. 



5. C. Nuttalliana, Steud. Culm stout (3° -5° high); panicle contracted 

 and spike-like; glumes lanceolate and tapering into slender awl-shaped tips, 

 3" long ; hairs on the lower side scanty and barely half the length of the firm and 

 keeled lower palet, on the other side longer and equalling the copious tuft on the 

 summit of the rudiment ; awn borne half-way between the middle and the taper- 

 ing tip of the palet, stout, not twisted ; grain bearded at the top. (C. Canaden- 

 sis, Nutt'. C. coarctata, Torr., and of former ed.) — Moist grounds, E. New 

 England to Pennsylvania, Virginia, and southward. Aug. 



6. C. Porteri, Gray. Culm slender (2° -4° high); a woolly-bearded ring 

 at the junction of the broadly linear leaves with the sheath; panicle long and 

 narrow, with the branches appressed ; glumes lanceolate, acute, pale, 2" to 2i" 

 long; hairs of the flower and of the short rudiment scanty, and both reaching about 

 to the middle of the flower behind the upper palet, but very short or none at the 



