139. GRAMINE.E. [62. Isch^emum. 



62. ISCHiEMUM, L. 



Usualh^ perennial with the leaf-blades convolute Avhen young and 

 generally membranous ligules. Spikelets binate, sessile and pedi- 

 celled similar or more or less heteromorphous on the articulate fragile 

 compressed rhachis of 2-nate, digitate or fascicled spikes (spiciform 

 racemes). Joints and pedicels flattened or subconcave on the inner 

 side and usually stout. Sessile spkts. dorsally compressed, often 

 rather broad. Glumes 4. Gl. i dorsally flattened or somewhat 

 convex and usually coriaceous below, thinner and distinctly nerved 

 above, truncate or 2-cuspidate (2-3-toothed in angustifolium), more 

 or less 2 -keeled with intlexed mai'gins ; ii as long or longer, narrower 

 and cymbiform, sometimes with a slender awn; iii usually male, 

 membranous with narrow ciliate palea nearly as long as gl. ; iv 

 usually 2-sexua] and nearly as long as i, cleft into lanceolate lobes 

 with a long awn from the sinus, nerves usually 3 above meeting in 

 the base of the awn, palea nearlv as long, linear-lanceolate (broad in 

 angustifolium). Peel. spkt. usually more or less reduced, sometimes 

 laterally compressed, often broader male or neuter. Lodicules 

 cuneate-quadrate. 



Sfa])/ hn» separated from lu-hcemHin the nev%- g-emis; PoUinidhim. This unfor- 

 tunately affects one of our best-known g-rasses, Ixchamum a nfjnsfi folium, winch is 

 appai-eiitly the only species in it. I have retained angustifulium therefore in our 

 Key to species. It certainly differs in several points from lachfpmum, but the 

 multiplication of genera of "one or few species appears undesirable, especially 

 where it upsets well-known names. The section Sehima is also restored to generic 

 rank. This is altogether desirable and the genus is a good one. It includes laxnm 

 which I have also retained in the kej' below for convenience of those who should 

 look for it there. 



I. Glume i of sessile spkt. not channelled or depressed along 

 the mesial line. Spikes clustered, only exceptionally 

 solitary : — 



A. Glume i of sessile spkt. with margins onl3- narrowly- 



inflexed throughout : — 



1. Base of stems not woollj-. CtI. i not toothed : — 



Gl. i nearly tiat dorsally. Perennial .... arhtafnm.* 

 Gl. i very convex and prominently transversely 

 rugose dorsally. Annual 1. rugosnin. 



2. Base of stems woolly. Gl. i 2-3-toothed at apex and 



with a tuft of hair dorsally a»gttstiJ'oliuii>.\ 



B. Gl. i with broadly incurved margins below the middle, 



flat membranous and nerved above : — 

 Gl. i with 2 terminal wings; ii with alate keel . . 2. cUlare. 

 Gl. i 2-keeled, not winged above; ii not winged . . 'd. hirtum. 

 II. Gl. i of sessile spkt. deeply depressed along the mesial 



line. Spikes always solitary ...... Inxnm.t 



1. I. rugosum, Salisb. Moraro, S. 



Erect, 1-2 ft. high with branched leafy stems. Leaves narrow 

 2-5-10" by -IS-'S", Avidest at or little above the middle, sharply 

 acuminate. Spikes 1-2 together yellow scarcely exserted from the 

 leaf axils or long-peduncled, 1-3-5" long. Spkts. •15-'18" long, 

 easily recognised by the broad-oblong gl. i of the sessile spkt. being 



* Arhtatnm is said to occur throughout India, but although found in Central 

 Bengal there is at present no specimen from our area. 

 i See under PoUinidium. 

 X See ww&QY Sehima uerco^Km. 



1021 



