562 GRAMINE^:. (GRASS FAMILY.) 



on leafless radical culms ; lower palea (6" long) ovate-lanceolate, smooth, fringed 

 on the margins, awn-pointed. (Arundo tecta, Walt.) Swamps, Florida to 

 North Carolina. Feb. and March. 



30. BRIZOPYRUM, Link. 



A low and rigid perennial dioecious grass, growing in saline marshes, with 

 linear-subulate involute distichous leaves, and many-flowered compressed spike- 

 lets, crowded in a nearly simple spike. Glumes and paleae smooth, somewhat 

 coriaceous, obtuse, compressed, not keeled ; the lower ones several-nerved. Sta- 

 mens 3. Stigmas 2. Grain oblong, free. 



1. B. spicatum, Hook. Rootstocks long and creeping; culms 1 high ; 

 leaves spreading, rigid, 2' -4' long, smooth, like the imbricated sheaths ; spike- 

 lets oblong, 7-15-flowered. (Uniola spicata, Ell.) Low sandy shores and 

 marshes, West Florida, and northward. Aug. and Sept. 



31. POA, L. MEADOW-GRASS. 



Grasses with tufted culms, smooth flat and tender leaves, and compressed few- 

 flowered spikelets in loose or contracted panicles. Glumes unequal, shorter 

 than the flowers. Lower palea nearly membranaceous, keeled, scarious on the 

 margins, awnless, 5-nerved, the three more prominent nerves mostly hairy or 

 woolly below ; upper palea 2-toothed, falling at maturity with the lower one. 

 Stamens 2-3. Stigmas plumose. Grain free. 



* Branches of the panicle single, or by pairs. 



1. P. annua, L. Annual; culms tender, spreading, 6-10' high; leaves 

 linear, 3' -6' long, l" wide; panicle ovate, the smooth branches at length 

 reflexed ; spikelets ovate, about 5-flowered ; glumes obtuse or emarginate, half 

 as long as the sparsely hairy obtuse flowers. Yards and gardens, Florida, and 

 northward. Feb. and March. Introduced. 



2. P. cristata, Walt. "? Annual; culms erect, 6' -10' high; leaves linear, 

 subulate, 1 ' long, " wide ; panicle linear or lanceolate, dense, the lowest of the 

 rough branches spreading ; spikelets 3 - 5-flowered ; lower palea with a promi- 

 nent crest-like fringe on the back, barely longer than the acute glumes. Dry 

 soil around Quincy, Middle Florida. April. 



3. P. flexuosa, Muhl. Perennial; culrns weak, mostly erect, 1-1^ 

 high ; leaves narrowly linear ; branches of the panicle by pairs (l'-2' long), 

 capillarv, widely spreading ; spikelets 2-4 near the summit of each branch, pale, 

 oblong, 3 - 4-flowered ; glumes acute ; lower palea compressed and very obtuse 

 at the apex, hairy on the nerves. (P. autumnalis, Ell.) Rich shaded soil, 

 Florida, and northward. May. 



* * Branches of the panicle 3 - 6 in a cluster : perennials. 



4. P. pratensis, L. Culms terete, ascending from a creeping base ; leares 

 mostly abruptly pointed ; branches of the panicle expanding, about 5 in a clus- 

 ter ; spikelets ovate, 3 - 5-flowered, crowded ; flowers closely imbricated ; lower 



