530 POACE^. 



r. Ligvile 2.5 mm. long, rays 2-5, floral 



glume 3-5 mm. long. 40 



r. Ligule 3 mm. long, rays 3-5, floral glume 



5.5-6.7 mm. long 41 



r. Ligule 4 mm. long, rays 2, floral glume 4 



mm. long 42 



r. Ligule 5 mm. long, rays 4-5, floral glume 



3.5-4.5 mm. long 43 



1. P. ANN-UA L. Sp. PL G8 (1753). Low Spear-grass. 

 AxxuAL PoA. p. supina Schratl. Fl. Germ. 1:289 (1806). P. 

 triangvlaris Gilil). Exercit. 2: 531. P. duriuscuhi AVilld. Spring. 

 Syst. 1:339 (1824). P. humiUs Lej. Fl. Spa. 1:49. P. ovalis 

 Tineo, PL Ear. Sicil. 21 (1846). 



A soft smooth bright, light-green annual, sometimes glaucous; 

 culms weak, compressed, 5-30 cm. high. Ligule 2-3 mm. long ; 

 blades of the sterile shoots half or two-thirds as long as the culm, 

 •often with wavy margins, those of the culm 3, flat or conduj^licate, 

 abruptly acute, the upper 1-4 cm. long, about 2 mm. wide. Pani- 

 cle sometimes purplish, ovoid or pyramidal, subsecund, 2-5 cm. 

 long, rays mostly in pairs, the longest 2.5 cm. long, sometimes 

 drooping, bearing spikelets on the upper half. Spikelets very 

 short-pedicelled, 4-6 mm. long, 3-7-flowered, oval or ovate-lanceo- 

 late, joint of rachilla 0.7 mm. long; empty glumes compressed, 

 first 1-3-nerved, second 3-nerved, broadest at or above the middle, 

 usually 2.5 mm. long; floral glume ovate-oval, smooth, erose at 

 apex, 2.8-3.1 mm. long, with soft hairs on the keel for half or two- 

 thirds of its length and on the lower part of the lateral nerves, 

 the 4 lateral nerves parallel or divergent, evanescent one-third of the 

 way from the apex; palea 2.5-2.8 mm. long, ciliate or pubescent 

 on the keels. 



Cultivated and waste grounds, almost everywhere. 

 In central Michigan three or more crops may be grown from the 

 seed in one season. Li shady places, where carefully watered, it 

 produces a very nice lawn, especially noticeable owing to the pleas- 

 ant light-green foliage. 



Vermont, PringU ; Pennsylvania, Scrihier for U. S. Dept. 



