640 GRAMINE^. (grass family.) 



48. DANTHONIA, DC. Wild Oat-Gkass. (PI. 12.) 



Lower palet (oblong or ovate, rounded-cylindraeeous, 7-9-nen'ed) bearing 

 between the sharp-pointed or awn-lilvc 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. spic^ta, Beauv. Culms tufted, low; leaves short, very narrow j 

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

 Dry and sterile or rocky soil. June - Aug. 



2. D. serlcea, Nult. Taller and not tufted (l°-3° high); leaves larger; 

 spikelets more numerous and panicled, 6" - 9" long ; lower palet very silJcy-villom, 

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

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

 rare. June. 



49. AVENA, L. Oat. (PI. 12.) 



Spikelets 2 - many-flowered, panicled ; the floivers herbaceo-chartaceous, or 

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

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

 nervcd, 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 Common Oat 

 (A. satIta, 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 (l°-2'' 

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

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

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

 smooth ; flowers 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. (Trisfetum purpurascens, Torr.) — Kocky, shaded hills, N. New 

 England, New York, and northwestward. June. 



2. A. Smithii, T. C. Porter, n. sp. Taller (2J°-4J° 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 ; flowers (3-5) not hairy-tufled at the base ; awn one third or half 

 the length of the 7-nerved palet, straight. — Isle Royalo, 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, 

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



