GRAMINEAE, 1 15 



shorte: than the third scale. On sandy shores, western Ont. and Manitoba to the 

 Rocky Mts., south to Ind., Kans. and Colo. July-Sept. 



45. APERA Adans. 



Annual grasses, with narrow flat leaves, and ample open or contracted panicles. 

 Spikelets I -flowered, small, the rachilla prolonged beyond the flower into a bristle. 

 Scales 3; the 2 outer empty, unequal, thin, membranous, keeled, acute; the third 

 scale a little shorter, membranous, bearing a long slender awn inserted just below 

 the shortly 2-toothed apex; palet a little shorter than the scale, 2-keeled, 2-toothed. 

 Stamens 3. Styles distinct, short. Stigmas plumose. Grain narrow, free, in- 

 cluded in the scale. Seed adherent to the pericarp. [Greek, signifying not muti- 

 lated, whole or entire; application uncertain.] Two species, natives of Europe and 

 western Asia. 



1. Apera Spica-venti (L.) Beauv. Silky Bent-grass. Windlestraw. 

 (I. F. f. 383.) Culms 3-6 dm. tall, erect, simple, slender, smooth and glabrous. 

 Sheaths usually longer than the internodes, the upper one generally including the 

 base of the panicle; leaves 2.5-17.5 cm. long, 1-4 mm. wide, scabrous; panicle 

 7.5-22.5 cm. in length, the branches erect or ascending, capillary, 3.75-7.5 cm. 

 long; outer scales of the spikelet 2-2.5 mm « l° n g- acute, smooth and shining; third 

 scale hairy or nearly smooth, bearing a dorsal scabrous awn 6-8 mm. long; rudi- 

 ment at the end of the rachilla less than 0.5 mm. long. In waste places and on 

 ballast, Me. to southern N. Y. and Perm. Adventive from Europe. June-July. 



46. HOLCUS L. 



Annual or perennial grasses with flat leaves and spike-like or open panicles. 

 Spikelets deciduous, 2-flowered; lower flower perfect, upper staminate. Scales 4; 

 the 2 lower empty, membranous, keeled, the first 1 -nerved, the second 3-nervedand 

 often short-awned; flowering scales chartaceous, that of the upper flower bearing a 

 bent awn. Palet narrow, 2-keeled. Stamens 3. Styles distinct. Stigmas plu- 

 mose. Grain oblong, free, enclosed in the scale. [Greek, taken from Pliny.] 

 About 8 species, natives of the Old World. 



1. Holcus lanatus L. Velvet-grass. Meadow Soft-grass. (I. F. f. 384.) 

 Softly and densely pubescent, light green. Culms 4.5-9 dm. tall, erect, often 

 decumbent at the base, simple ; sheaths shorter than the internodes; leaves 

 2.5-15 cm. long, 4-12 mm. wide; spikelets 4 mm. long, the empty scales white - 

 villous. the upper awn-pointed; flowering scales 2 mm. long, smooth, glabrous and 

 shining, the lower sparsely ciliateon the keel, somewhat obtuse, the upper 2-toothed 

 and bearing a hooked awn just below the apex. In fields, meadows and waste 

 places, N. S. to Ont. and 111. ; south to N. Car. and Tenn. Also on the Pacific 

 Coast. Naturalized from Europe. June-Aug. 



47. AIR A L. 



Mostly annual grasses with narrow leaves and contracted or open panicles. 

 Spikelets small, 2-flowered, both flowers perfect. Scales 4; the 2 lower empty 

 thin-membranous, acute, subequal, persistent ; the flowering scales usually cor 

 tiguous, hyaline, mucronate or 2-toothed, deciduous, bearing a delicate dorsal awn 

 inserted below the middle; palet a little shorter than the scale, hyaline, 2-nerved. 

 Stamens 3. Stigmas plumose. Grain enclosed in the scale and palet, and often 

 adhering to them. [Greek name for Loliiwi temidentiun.~\ Four or five species, 

 natives of Europe. 



Panicle open ; flowering scales about 2 mm. long ; plants 1.25-2.5 dm. tall. 



1. A. car yophy Ilea. 

 Panicle contracted ; flowering scales about 3 mm. long ; plants 5-10 cm. tall. 



2. A praecox. 



I. Aira caryophyllea L. Silvery Hair-grass. (I. F. f. 385.) Smooth 

 and glabrous throughout. Culms 1.25-2.5 dm. tall, erect from an annual root, sim- 

 ple, slender; sheaths mostly basal; leaves 1.25-5 cm - l° n & involute-setaceous; 

 panicle 2.5-10 cm. in length, open, the branches spreading or ascending, the lower 

 2.5 cm. long or less ; spikelets 2-2.5 mm - l° n & the empty scales acute ; flowering 



