18 POACEAE. 



28. LEPTOCHLOA Beauv. Often tall grasses, with flat or convolute 

 leaf-blades, and an inflorescence consisting of very many long slender spikes 

 arranged in a panicle, rarely approximate at the summit of the stem. Spikelets 

 small, close, or rarely scattered, 2-several-flowered, rarely 1-flowered, flattened, 

 sessile, alternate in 2 rows. Scales 3-several, keeled, obtuse, acute, or shortly 

 awned, the 2 lower empty, a little unequal, usually shorter than the spikelet, 

 or in the 1-flowered spikelets exceeding the third scale, the remaining scales 

 more obtuse or sometimes bearing a slender awn, each of the lower enclosing 

 a prominently 2-keeled palet and a flower, the upper empty. Stamens 3. 

 Styles distinct. Stigmas plumose. 



1. L. domingensis (Jacq.) Trin. Stems 2-10 dm. tall: leaf -blades 1-3 dm. 

 long, 1 cm. wide or less: inflorescence 1-2 dm. long: spikes 3-10 cm. long: 

 spikelets 2-3 mm. long: flowering scales 1.75-2.25 mm. long, acute, the lateral 

 nerves pilose for part way above the middle, the midnerve, hispidulous above 

 the middle. Hammocks and cultivated grounds, U. keys, L. keys. (Bah., 

 Cuba, Ant.) 



29. PHRAGMITES Trin. Tall erect plants with flat usually broad leaf- 

 blades and ample terminal panicles. Spikelets 2-several-flowered, the lower 

 flower staminate, the remainder perfect. Scales 4-several, the first much shorter 

 than the second, the remaining scales long-acuminate. 



1. P. Phragmites (L.) Karst. Stems 1-5 m. tall, from long rootstocks: leaf- 

 blades 1.5-3 dm. long or more, 1-5 cm. wide, flat: panicle ample, 1.5-3 dm. 

 long or more: spikelets crowded, the flowering scales 10-12 mm. long. Shore 

 hammocks and lime-sinks, U. keys. [E. K.] (Bah.) COMMON-REED. 



30. MONANTHOCHLOE Engelm. Perennial creeping or stoloniferous 

 monoecious grasses, with short rigid convolute leaf-blades crowded at the 

 nodes, and an inconspicuous inflorescence concealed among the leaves. Spike- 

 lets unisexual, the staminate hardly sessile and in pairs, or stipitate and single. 

 Scales 4 or 5, the 2 outer somewhat resembling the floral leaves, membranous 

 and sheathing at the base, linear, rigid and spreading above, many-nerved, the 

 remaining scales membranous, firmly hyaline. 



1. M. littoralis Engelm. Branches densely tufted from creeping stems, 1-5 

 dm. tall, stiff, wiry: leaf -blades crowded on short branches, widely spreading, 

 1.5 cm. long or less, stiff, often curved. Hammocks, sand-dunes and shores, 

 U. keys, L. keys, L. S. keys. (Cuba.) 



31. TRIDENS E. & S. Usually perennial grasses, with the inflorescence 

 of open or contracted panicles. Spikelets 3-many-flowered. Scales 5-many: 

 flowering scales 3-nerved, the midnerve or all the nerves excurrent, the mid- 

 nerve and the lateral nerves or the margins pilose. 



1. T. eragrostoides (Vasey & Scribn.) Nash. Stems 3-12 dm. tall: leaf -blades 

 2-3 dm. long, 4-7 mm. wide: panicle 1.5-3 dm. long, its rough branches ascend- 

 ing, 3-12 cm. long: spikelets 7-10-flowered, 2.5 mm. broad, ovate: flowering 

 scales about 2.5 mm. long, oval and about 1.5 mm. wide when spread out, the 

 apex rounded or nearly truncate, denticulate, the midnerve usually excurrent. 

 Hammocks and lime-sinks, Key West. 



32. DIPLACHNE Beauv. Tufted often tall grasses, with an inflorescence 

 of numerous long slender spikes or racemes (rarely reduced to one and 

 terminal), racemosely arranged on a long axis. Spikelets linear, sessile or 

 nearly so, many-flowered. Scales many, membranous. 



