GRAMINEAE (GRASS FAMILY) 135 



short branches erect; spikelets 4-6 min. long; glumes acute, slightly exceeding 

 the floret; lemma obscurely dentate, awn twisted below; palea about as long 

 as the lemma, callus-hairs scanty, $-| as long. Dry woods, N. Y. and Pa. 

 Aug. 



:;. C. perp!6xa Scribn. Similar to the preceding, slightly glaucous ; panicle 

 oblong-lanceolate, contracted, 1-1.5. dm. long, the slender fascicled branches 

 erect or ascending, densely flowered ; spikelets 3.5-4 mm. long; glumes acumi- 

 nate ; awn slightly twisted below ; palea and copious callus-hairs f the length 

 of the lemma. (C. nemoralis Kearney, not Philippi.) Rocky woods, Me. and 

 w X. Y., local. 



* * Awn straight or nearly so, included ; callus-hairs usually not much shorter 



than the lemma. 



- Panicle loose and open, even after flowering ; the mostly purple-tinged or 

 lead-colored strigose-scabrous glumes not closing in fruit . copious callus- 

 hairs about equaling the lemma, not surpassed by those of the rudiment; 

 awn delicate. 



4. C. canadSnsis (Michx.) Beauv. (BLUE-JOINT GRASS.) Culms 6-15 dm. 

 high, clustered ; leaves 1.5-4 dm. long, flat, involute in drying, glaucous ; panicle 

 1-3 dm. long, the slender fascicled branches ascending or 

 spreading; spikelets 3-3.5 mm. long; glumes equal, acute, 

 scarcely exceeding the thin erose-truncate lemma ; awn incon- 

 spicuous ; callus-hairs copious, about as long as the floret. 

 Wet places, e. Que. to N. J., and westw. June, July. FIG. 



108. Var. ACUMIN\TA Vasey. Glumes 4-5 mm. long, attenu- 

 ate, exceeding the acute lemma ; awn less delicate and longer. 108. c. canadensis. 

 Lab., Nfd. ; White Mts., N. H. ; Roan Mt., N. C. ; and in SpikeletxS. 

 Rocky Mts. 



6. C. Langsd6rfii (Link) Trin. Similar to the preceding; panicles usually 

 smaller; spikelets 5-6 mm. long; glumes acuminate, somewhat exceeding the 

 dentate lemma ; awn as long as the floret, less delicate than in C. canadensis. 

 Moist meadows, Lab., nits, of N. E., L. Superior, and northwestw. Aug. 

 (Greenl., Eurasia.) 



I- -i- Panicle contracted, strict, its short branches oppressed or erect after 

 flowering; the scabrous glumes mostly closed; lemma less delicate, some- 

 times as firm in texture as the glumes; awn stouter. 



6. C. negllcta (Ehrh.) Gaertner, Meyer & Scherbius. Eoatstock slender; 

 culms slender, 4-6.5 dm. high ; leaves soft, 1-3 cm. long, smooth; panicle nar- 

 row, glomerate and lobed, 5-10 cm. long; spikelets about 4 mm. long ; glumes 

 acute ; callus-hairs a little shorter than the floret, and as long as those of the 

 rudiment; awn from the middle of the thin lemma or lower, barely exceed- 

 ing it. (C. stricta Man. ed. 6, not Trin.) Wet shores and mountains, n. 

 N. E., L. Superior, northw. and westw. (Eurasia.) 



7. C. hyperborea Lange. Culms and rootstocks stouter than in the preceding ; 

 culms tufted, 4-10 dm. high ; leaves involute, rigid, roughish ; panicles 7-15 cm. 



long, dense ; spikelets 4-4.6 mm. long ; glumes acute, exceeding 

 the floret ; callus-hairs l~\ as long as the lemma. {C. lappo- 

 nica Man. ed. 6, not Kartin.) Moist meadows and calcareous 

 cliffs, Greenl. to Alaska, s. to e. Que., n. Vt., "Pa.," Minn. ; 

 and in the Rocky Mts. 



8. C. inexpansa Gray. Culms solitary or few, slender, 



109. C. inexnansa. 7-12 dm. high ; leaves 1.5-3 dm. long, 3-6 mm. wide, scabrous 

 Spikelet with de- above, flat, often involute in drying ; panicles pale, 1-2 dm. 

 tached glumes x 2. long, less densely flowered than others of this group ; spikelets 



4 mm. long ; glumes rather rigid, sharp-pointed, about J longer 

 than the toothed lemma ; awn scarcely exceeding the lemma ; callus-hairs 

 J shorter than the lemma. (C. conflnis Man. ed. 6, not Nutt.) Swamps and 

 low prairies, N. Y. and N. J. ; Minn, to Mo. and westw. July. FIG. 109. 



