322 CTRIANDRIA DIGYNIA. o Ischemum, 
ed, three-sided, with the angles very hairy.— Flowers in pairs, one 
sessile, the other pedicelled,  Pediced three-sided, and ciliate.— Ca- 
_ yx of the sessile flowers two-valved, two-fiowered ; one floret herma- 
phrodite, the other male. — Exterior valve striated, with its anterior 
margins and apex enlarged with a broad, membranaceous, bifid bor-. 
der; inner valve boat-shaped, keeled, ciliate, and sub-aristate, one 
floret male, the other hermaphrodite.—Corol, glumes of each floret 
two-valved ; the exterior one of the hermaphrodite floret bifid, witha - 
Jong arista in the fork.—Calyx of the pedicelled flower two-valved, 
two-flowered ; valvelets equal, boat-shaped, keeled, ciliate, and sub- 
aristate; one floret male, the other hermaphrodite.— Corol, as in the 
sessile flowers, and also awned in the same manner. 
Obs. I am not certain that this is the original I. aristatum of i 
neus and Retzius. 
pem 
2. I. rugosum. Linn. Sp. Pl. ed. Willd. iv. 940. 
Erect, ramous. Leaves lanceolate ; spikes paired, both-flowers 
awned; calyces oblique, obtuse, hard, and transversely rugose. 
Is generally found growing among rice, and is so much like 
it, the inflorescence excepted, that they are not, till in flower, 
to be distinguished.— Leaves large, smooth ; mouths of the sheatlis 
crowned with along, two-parted ligula. ede terminal, and from 
the exterior axils paired, erect, from two to three inches loug. Rachis | 
jointed.— Flowers in pairs ; ; one sessile, the othér on a short, thick, 
angular clubbed pedicel. ; 
SESSILE FLOWER. Calyr two- flowered, two-valved ; valvelets 
in size nearly equal, the exterior one rugose, and very hard; one of 
the florets hermaphrodite, the other male, each with two membrana- 
ceous valves; the inner valve of the hermaphrodite flower has a long 
twisted awn issuing from the middle of its back. 
PEDICELLED FLOWER smaller. Calyx as in the other, but con- 
taining two male flowers, one of which is also awned. 
* 
3. L sei isagittatum. R. ; 
Aunuil. Leaves ovate-lanceolate, semisagittate. Spikes paired, - 
i 
