Margin of the first glume of the sessile spikelet broadly incurved from below the middle. First glume of the sessile spikelet with smooth margins, callus bearded. 4. I. ciliare. Raceme solitary; the first glume of the sessile spikelet deeply grooved at the back along the middle line. 5. I. laxum. =Ischaemum aristatum, _L._= This is a perennial grass, with fairly stout, erect or somewhat decumbent, simple or branched, glabrous, leafy stems, 1 to 4 feet high. The _leaf-sheath_ is loose, glabrous and auricled. The _ligule_ is a distinct membrane, broad or narrow. _Nodes_ are glabrous. The _leaf-blade_ is linear-lanceolate, flat, acuminate, narrowed towards the base which may be acute, subcordate or rarely even petiolate, glabrous or sparsely hairy above and glaucous beneath, 4 to 10 inches long and 1/4 to 1 inch broad. The _inflorescence_ consists of one or two, erect, stout or slender, fragile racemes, 1 to 5 inches long. [Illustration: Fig. 130.--Ischaemum aristatum. 1. A portion of the raceme showing the joints, sessile and pedicelled spikelets; 2, 3, 4 and 6. the first, second, third and the fourth glume, respectively, of the sessile spikelet; 5 and 7. palea of the third and the fourth glumes, respectively; 8. ovary, stamens and lodicules; 9. first glume of the pedicelled spikelet.] The _spikelets_ are 1/6 to 1/3 inch long, the sessile and the pedicelled closely pressed together, glabrous or hairy; the callus of the sessile spikelet broad and thick, with or without hairs. The _sessile spikelet_ is awned and consists of four glumes. The _first glume_ is 1/5 inch long or less, oblong or linear-oblong, cartilaginous below the middle, with two to four (or rarely up to six) marginal nodules on each edge, sometimes these are connected by shallow ridges, thinner above the middle, with green anastomosing veins, tip obtuse or 2-toothed, and margins narrowly incurved. The _second glume_ is chartaceous, lanceolate, acuminate, 1-nerved and with a smooth rounded keel. The _third glume_ is ovate-lanceolate, membranous, 1-nerved, acuminate, male or bisexual with an oblong palea. The _fourth glume_ is cleft to or below the middle into lanceolate acute lobes, with a brownish red awn 1/2 inch or more long at the sinus twisted at the lower portion and straight above, paleate, usually female; _palea_ is linear oblong. The _pedicelled spikelet_ is as long as the sessile, inarticulate on the very thick, short pedicel which is densely or sparsely hairy at the base. The _first glume_ is scimitar-shaped, coriaceous, acute, with a somewhat semi-circular wing. The other _glumes_ are as in sessile spikelets, but the fourth glume has no awn and may have a mucro.