TRIANDRIA. DIGYNIA. 71 



From Divithonia of Decandolle, {Festitca decumbens, 

 LiN.) it IS scarcely dsiing-lshable exctpt by liubi, pro- 

 ducing lii bv ti: s[jecits a sj.readiiig' and rannfied parucie, 

 wuh a cuiiu or' 3 or 4 i'eet elevation, in place of a simple 

 ract.nie, and a ci-lm of 6 inches or a toot, it is al.so desti- 

 tute of tne lai\ue tolliculose calix of Uanthonia, which in- 

 chides, and indeed exceeds in leni,th ail the floscu- 

 li of the spTkelet- The cal;X ot IViiulsoria is, iiowever, 

 lai'ger than the glumes of the corc^Ua, taken singl},and 

 also of a very diherent structure, b»it the spikelet is at 

 the same time about twice the lenjfihoi the calix. 



100. DANTHOMA. Dcandolle, 



Calix 2-vaIve(l, many flowered, very large, 

 equal lo or exceeding tlie inrlud?d spikelet. 

 Exterior valve of tlie corolla c«>ncave, with the 

 points emarginate, mucronate, awned, or un- 

 armed and tlien trifid. 



Small grasses, producing- for the mo-t part, a simple 

 raceme of spikciets, (usually troin 4 to 13); clix conflii- 

 enriy nerved, fblliculose, exceednig or equaiing (he apike- 

 le ; spicuh from 4 to 9 flowered. dor>ai \alve acute or 

 acui> inate, (not obtuse or almost truncated as in Wind' 

 soria,) bifid, with a central, membranaceous, and flat- 

 tened awn, contorted at the base, or siniply trifid, (ne- 

 ver quadrifid or o-toothed); mner valve oliaie. 



S p F ci F.s. 1. D. spicata, {Avenu spicata L. ) Culm about a 

 foot niirh.slmder, erect, decumDeni at ihe first and second 

 Hide; leaves subul?te, short, those of the root often hairy 

 on the upper suriacp; stipula obs'lete, cibate; laceme 

 simple, or subdivided ne.r the buse; spikelels 4 to 9; calix 

 longer than the .spikelet, confluenlly 5-nerved, cons ex, 

 acute, witi! scariose purple niar;<ins; flosculi 6 (jr 7; uu.er 

 valve oval, convex, acumina e, seiaeeously bifid. With an 

 intermediate, flat, exst-i-fd, smooth awn, discoloured and 

 contorted at its base, obsoietely many-nerved, nerves pili- 

 ferous, margin scario.Ne; inner vaive deeply appres^ed, ci- 

 liate styles sessile, sin>ply pi imose, slender, while; pe- 

 risporium 2-lcaved, obiu»e. 



Tois species is very nearly allied to Bromus. 



2. *sericea. Culm erect; fact- me conpounded, branches 

 2 and 3-flowered; spikelevs 9 to 13, 8 and 9-flowered, 

 somewh t shorter than the calix; corolla valves very un- 

 equal, outtr lanct olatf, denselv vni-ms on the margin, 

 seioscly b fid a^ the point, wiih'a cenu'ai contorted awjl; 

 inner valve ciliate, much shorter. 



