TRIA.NDRIA. DIGYNIA. 65 



Early flowering- subalpine grasses, growing in calcare- 

 ous mountains. 



Species. 1. S. * Dactyl oides. Culm setaceous, leafy; 

 leaves short, flat, subulate, and somewhat hairy; stipules 

 bearded; spikes 2 or 3, few. flowered; flowers in 2 rows, 

 disposed upon an unilateral rachis, caiix mostly 2 flower- 

 ed, and will) the corolla acuminate and entire. 



Hab On the open grass; plains otilie Missouri; abun- 

 dant. Flowers in May and June. v.v. Root afier flower- 

 ing resembling a bulb. 



Culm sa ooth and round, furnished with 2 or 3 leaves, 

 about 4 or 5 inches high. Leaves flat, subulate, and 

 somewhat hairy, 1 to 2 inches in length, and about 2 

 lines wide; sheathes shorter than the internodes, very 

 hairy around the stipules. Spikes 2 or 3, somewhat oval, 

 subtended by a single leaf with which they are at first 

 sheathed; rachis compressed, margined, spikelets 6 lo 8, 

 by pairs, inclined to one side. Calix 2-valved, 2 or S-flow- 

 ered, valves very unequal, each with a single nerve and 

 carinate, the larger oblong-ovate, mucronulate. Outer 

 valve of the corolla oblong-lanceolate, entire, 3-nerved, 

 smooth, and m-r'mbranaceous, longer than the cahx; inner 

 2-nerved, nearly the length of the outer. Anthers linear, 

 entire, fulvous, exserted. Styles filifurm, p\ibescv'nt. 



This species appears on the om hand. alUed to ^ithe- 

 ropogou, and on liie oiher to DactijUs. Though rather a 

 Sesleria than any other genus, it recedes from it in hav- 

 ing the valves of the corolla entire at the apex, and thus 

 it approaches DactyliSiCX least, the D. glfnnerata. 



\\\ih tlie exception of the present species, the genus 

 Sesleria is confined to the alpine regions of Northern 

 Europe. 



§ III. Calyces many Jloweredf scattered. 

 96. POA- L. (MeacnAv-grasH.) 



Caiix 2'Valvrd, wianj tlowcrcd. Spikelets 

 more or l^^ss ovate, \vltj>out awns, valves sonie- 

 \v}»at acute, diSi oloured, with scariose mar- 

 gins. 



Flowers panicidate, panicles many-flowered, branches 

 often semivtrticiil'5e, o^e sided, coardate, or spreading; 

 in several species the flower glumes are connected at the 

 base by a tomentunn or villus. 



Species. 1. P. tn'vialis ^. pratensis. 3. viridls, (distin- 

 guished ti*om I*, praieims by the remarkable compres- 



