640 GRAMINE^E. (GRASS FAMILY.) 



48. DANTHONIA, DC. Wi LI? OAT-GRASS. (PL 12.) 



Lower palet (oblong or ovate, rounded-cylindraceous, 7-9-nerved) bearing 

 between the sharp-pointed or awn-like teeth of the tip an awn composed of the 

 3 middle nerves, which is flattish and spirally twisting at the base : otherwise 

 nearly as in Avena. Glumes longer than the imbricated flowers. Ours peren- 

 nials, l-2 high, with narrow and soon involute leaves, hairy sheaths bearded 

 at the throat, and a small simple panicle or raceme of about 7-flowered spikelets. 

 (Named for Danthoine, a French botanist.) 



1. D. spicata, Beauv. Culms tufted, low; leaves short, very narrow 5 

 spikelets few, 3" -5" long; lower palet loosely hairy, its teeth short and pointless. 

 Dry and sterile or rocky soil. June -Aug. 



2. D. sericea, Nutt. Taller and not tufted (1- 3 high); leaves larger ; 

 spikelets more numerous and panicled, 6" -9" long; lower palet very silky-villous, 

 tipped with slender awn-pointed teeth. Dry or moist sandy soil, Southern Massa- 

 chusetts (Dr. Robbins), New Jersey ( C. E. Smith, C. F. Parker), and southward : 

 rare. June. 



49. AVENA, L. OAT. (PL 12.) 



Spikelets 2 - many-flowered, panicled ; the flowers herbaceo-chartaceous, 01- 

 becoming harder, of firmer texture than the large and mostly unequal glumes ; 

 the uppermost imperfect. Lower palet rounded on the back, mostly 5-11- 

 nerved, bearing a long usually bent or twisted awn on the back or below the 

 acutely 2-cleft tip proceeding from the midnerve only. Stamens 3. Grain ob- 

 long-linear, grooved on one side, usually hairy at least at the top, free, but in- 

 vested by the upper palet. (The classical Latin name.) The COMMOX OAT 

 (A. SATivA, L.) represents the large-flowered annual species of the Old World. 

 The following are smaller-flowered, indigenous perennials. 



1. A. Striata, Michx. Glabrous and smooth throughout, slender (T-2 

 high) ; leaves narrow ; ligule short, truncate ; panicle simple, loose ; spikelets 

 (6" long) on capillary pedicels, 3-6-flowcred, much exceeding the scarious- 

 margined purple acute glumes; the lower glume 1-, upper 3-nerved; rhachis 

 smooth ; jlowers short-bearded at the base ; lower palet 7-nerved, much longer than 

 the ciliate-fringed upper one (4" long), mostly shorter than its soon bent or 

 divergent awn, which rises just below the tapering very sharply cuspidate 

 2-cleft tip. (Trisetum purpurascens, Torr.) Eocky, shaded hills, N. New- 

 England, New York, and northwestward. June. 



2. A. Smithii, T. C. Porter, n. sp. Taller (2j- 4^ high), rather stout; 

 leaves broadly linear (3 ;/ -6" wide) and taper-pointed, flat, and with the sheaths 

 and culm retrorsely scabrous; ligule elongated, acute; panicle larger (6' -12' 

 long), the few branches at length spreading; glumes slightly purplish, scabrous 

 on the nerves, of which there are 3 in the lower and 5 in the upper ; rhachis mi- 

 nutely hispid ; Jlowers (3-5) not hairy -tufted at the base ; awn one third or half 

 the length of the 7-nerved palet, straight. Isle Koyale, Keweenaw Point, Lake 

 Superior, Robbins. Woods near Sault Ste. Marie, C. E. Smith, for whom the 

 species is named. April, May . To be compared with the Siberian A. callosa, 

 Turczaninow, which was referred to A. striata by Trinius. 



