TRIANDRIA. DIGYNIA. 41 



before evolution; llgula entire, conspicuous. Calix 2- 

 valved, 1-flowered, valves membranaceous, about twice 

 the leng-th of the corolla, ventricose and gibbous, above 

 the corolla contracted; both 3-nerved, tlie lateral nerves 

 only about one third the length of tlie glume, the central 

 nerve ending in a cusj) or short awn margined by the 

 glume at its base, nerves a little pubescent. Corolla 2- 

 valved, short, nearly oval, in fruit almost spherical, valves 

 coriaceous, vested with an exserted silky villus, extend- 

 ing beyond the corolla, the dorsal valve terminated by a 

 triquetrous pungent deciduous awn scarcely the length 

 of the calix, at first perfectly erect, afterwards a little 

 bent; the inner valve entirely enclosed by the outer and 

 witiiout awn. Stamna 3, scarcely exserted beyond the 

 valves of the -corolla; anthers small, brown, bifid at both 

 extremities, above termuiated by small pubescent tufts. 

 Sti'le 1. Stigmas 2, short, hirsutely villous. Ovarium 

 sheathed by a S-leaved perisporium (or nectary). Seed 

 nearly spherical. 



This genus is very nearly allied to Oryzcpsis, but at 

 the same time sufficiently distmct both in liabil and cha- 

 racter; having a culm with remarkable long sheathing 

 and almost filiform subulate leaves, a dichotomous spread- 

 ing panicle, a ventricose, coarctate, awned calix ; wice the 

 length of ihe corolla, which last is furnished with a deci- 

 duous awn, and a long silky villus. 



Habitat. On the grassy plains of the Missouri, 

 from the Aiikaree village to the Northern Andesr Flowers 

 in June and July. 



Order 2. — Digynta. 



t Calix \ -Jlowercdf flowers scattered, 



64. MUHLENBERGIA. Schreher, Dilept- 

 RUM. Michanx, 



Calix very minute, truncated, S-valved, un- 

 equal. Corolla 2-valved^ hairy at the base, ex- 

 terior valve terminating in a slender awn. 

 (^Style 1?) 



- Culm slender, leafy, terminating in a compounded 

 racemose appressed panicle. Calix persistent, as iu 

 ^'^srrostie, but txtremely minute: like an obtuse unequally 

 |)ifid scale in the jyr. diffusa; in the J\t. erecta one of the 

 'yalves is rather long and acute, according to the ob^jci:- 

 E 2- 



