Class III. Order III. 47 



volucre. The lower pairs of spikelets, however, have common- 

 ly a short setaceous involucre of four bristles springing from the 

 same number of callosities at base. Upwards, the bristles dimin- 

 ish in size and number, leaving only the callosities in their 

 place. Spikelets in pairs, widely divergent, three flowered. 

 Awn three or four times as long as the corolla. Woods. July. 



By an oversight, the late Dr. Muhlenberg has called the spike- 

 lets six to nine flowered. 



We have two varieties. 



ec. Three or four feet high, sheaths smooth, spikelets about 

 twenty, pubescent. 



/3. One or two feet high, sheaths rough, spikelets about ten, 

 glabrous. 



50. HORDEUM. 

 HORDEUM JUBATUM. Ait. Squirrel tail grass. 



Lateral florets abortive, their awns many times 

 shortest ; involucres setaceous, six times as long as 

 the flower. 



This grass is remarkable for the length and fineness of its 

 awns, which give to its spikes a hairy appearance. Stems slen- 

 der, smooth, and round, two feet high. Leaves rather short, 

 rough on the back and edge. Sheaths smooth. Receptacle com- 

 pressed, ciliate on the edges, jointed, breaking at the joints as 

 the plant dries. Flowers two ranked, one at each joint or tooth 

 of the receptacle. Each perfect floret is surrounded at its base 

 by an involucre of six long capillary awns, two of which are 

 distinct; the other four unite in pairs a short way from their 

 insertion, each pair with a minute, abortive floret in its fork. 

 Outer glume of the calyx lanceolate, ending in an awn six times 

 its length, and equalling those of the involucre. Marshes. 

 June. 



TR1GYJYM. 



51. LECHEA. 



LECHEA MAJOR. L. Large Pin weed. 



Hairy ; leaves oblong-lanceolate, flowers in fas- 

 cicled racemes, unilateral, on .short stalks. 



