Avena.] gramine^. 613 



than the glumes with long fulvous hairs at the base, outer glu- 

 mella bifid at the summit, root fibrous." — Br. Fl. p. 551. E. B. 

 t. 2231. Fl. Dan. t. 1629. Host. Gram. Aust. ii. t. 58. 



In cornfields and cultivated ground ; a frequent and very injurious weed. Fl. 

 July, August. 0. 



A tall grass, 3 or 4 feet in height. Root small, with downy fibres. Culms 1 or 

 more, round, hollow, shining, erect. Leaves most numerous below, linear, flat, 

 grayish green, rough, those towards the root often fringed with soft white hairs 

 near the stem, as are likewise their close, striated and long sheaths, often filamen- 

 tous along their edges. Ligule short, obtuse, usually much torn and jagged. 

 Panicle very large, at first unilateral and crowded, afterwards very diffuse and 

 spreading, its branches long, slender, angular, voughish, simple or slightly com- 

 pound, bearing numerous large, lanceolate, drooping spikelets on peduncles 

 thickened beneath each. Glumes equal, thin and chafiy, very acute, lanceolate, 

 with many strong green ribs running close and parallel, each with a double line 

 of scabrous points throughout its length. Florets usually 3, much shorter than 

 the glumes. Outer patea much like the glumes, but thicker in texture, wilh fewer 

 ribs, rough with tubercular prominences, bifid at the point, covered at the back 

 wilh fine, whitish or tawny, bristle-like hairs ; inner or superior palea ovato-lan- 

 ceolate, thin and flat, notched at the point, and having a single green rib along 

 each of its finely ciliated lateral margins ; awns very long, inserted on the back of 

 each floret about its middle, twisted for about half their length, at which point 

 they are suddenly bent, and then continued straight to the summit. Anthers yel- 

 lowish. Stigmas short, simple, feathery. Germen sealed on and almost concealed 

 amongst a dense tuft of soft white hairs. 



Its more valuable congener, the cultivated Oat {A. sativa, L.), differs from the 

 present species in its smaller and far less spreading panicle, which continues uni- 

 lateral to the last ; in its smoother less strongly ribbed florets, nearly devoid of all 

 hairiness benealh, one or more of which are abortive and wanting the awn, which 

 is shorter and not geniculate as in that. The florets of A. sativa are placed upon 

 a short vertical footstalk immediately under the base in a transverse po.sition, 

 whilst those of A.fatua stand laterally or obliquely upon their very short point of 

 insertion, and are all furnished with awns. 



2. A. strigosa, Schreb. 'Bristle-pointed Oat. " Panicle erect, 

 branches all secund, spikelets of 2 perfect florets each awned as 

 long as the glumes and terminated by 2 long straight bristles." — 

 Br.- Fl. p. 551. E. B. t. 1266. Host. Gram. Aust. ii. 41, t. 56. 



In cornfields and cultivated ground occasionally, but doubtless introduced. 

 Fl. "June, July."-JSr. Fl. 0. 



jB. Med. — Amongst potatoes by St. John's turnpike-gate, Ryde, JR£v. G. E. 

 Smith .'.'.' 



Root yellowish, fibrous. Culms several, about 2 feet high, erect, purplish be- 

 low, rather slender, with long, slightly inflated, ribbed sheaths, that are often a lit- 

 tle filamentous towards their summits. Leaves like those of the common Oat, flat, 

 roughish above and along their edges with minute prickles pointing forwards. 

 Ligule rather short, truncate and lorn. Panicle oblong, mostly leaning one way, 

 more slender than in the common Oat, the florets linear-lanceolate, on very long, 

 slender, partly compound pedicels. Glumes rather unequal, acute, roughish on 

 their keels ; outer and shorter with 9, inner and longer with 7, green ribs. Florets 

 2 (sometimes 4), both perfect, the inner one on a geniculate bearded pedicel, but 

 neither having any basal tuft as in A. fatua. Palea sprinkled with rough points, 

 7-ribbed ; outer one of each floret with a long, twisted, almost straight awn from 

 the middle of the back, and 2 much shorter terminal ones ; all rough, slender 

 and purplish ; inner palea flattish, acute, ciliated wilh soft hairs, and having a 

 single marginal green rib on each side. Anthers yellowish. Scale (nectary) wilh 

 2 very acute lobes. Scar nearly circular, neither transverse nor oblique, the 



