MR. G. BENTHAM ON GRAMINES. 133 
minent lower margin of the notehes of the rhachis as a rudimen- 
tary glume. 
8. KRALIKIA, Coss. and Dur., is a single Algerine species 
unknown to me, but well described, and evidently rightly placed 
in the present group. 9. OrorEerıum, Trin., is a dwarf East- 
Indian species remarkable for the cylindrical spike, with per- 
fectly immersed spikelets as in some Rottboellias and Ophiurus, 
but with the outer persistent glumes of Hordee&. 
The third subtribe Z/ymec comprises three genera, in which the 
spikelets are two or more, collaterally sessile at each notch of the 
spike, or the lateral ones very shortly stipitate. 
10. HonpEvw, Linn., was restricted by Beauvois to the common 
cultivated barley, H. vulgare, Linn., which in a great variety of 
forms is of very ancient cultivation, and whose indigenous origin 
is no more known than that of our wheats. Amongst these 
forms the East-Indian H. egiceras, Royle, has been proposed by 
E. Meyer as a genus under the name of Critho; but it cannot be 
otherwise considered than as aluxuriant monstrosity. The really 
spontaneous species of Hordewm amount to about twelve, distin- 
guished from Z/ymus by the single flower in each spikelet, and 
distributed into three sections :—1. Zeocriton, Beauv. ( Critesion, 
Rafin.), for the H. murinum, H. bulbosum, H. jubatum; Linn., and 
some others, in which the central spikelet alone of each three is 
fertile, the lateral ones sterile or reduced to empty glumes; 
2. Crithopsis, Jaub. and Spach (sect. Medusather of Elymus, 
Griseb.), for the H. crinitum, Desf., and its allies, with two per- 
fect spikelets at each notch, the intermediate one deficient or 
rarely represented by one or two empty glumes; 3. Cuviera, 
Koel., for the H. sylvaticum, Huds. (Elymus europeus, Linn.), 
with three collateral spikelets. 
11. ELymus, Linn., as now generally limited, comprises about 
twenty species, distributed into three sections, all distinguished 
from Hordeum in having two or more flowers to each spikelet :— 
1. Sitanion, Rafin. (Polyantherix, Nees), for the North-American 
E. Sitanion, Schult., with the flowering glumes usually three- 
awned; 2. Clinelyna, Griseb., with the spikelets usually two only 
to each notched and the flowering glumes with one long awn ; 
and 3. Psammelyna, Griseb., tall rigid species with often more 
than two spikelets to each notch, and the flowering glumes un- 
awned or with only very short awnlike points. 
LINN. JOURN.—BOTANY, VOL. XIX. M 
