POACEAE. 23 



mm. long: third scale 1.75 mm. long, awnlcss: fourth scale about 1.3 mm. long. 

 — Pinelands. 



30. GYMNOPOGON Boauv. Erect or diffuse plants M-ith flat, generally 

 short, Icuf-Madi's and numerous long slender spikes which are alternately 

 arranged or the lower ones subverticillate. Spikelets 1-flowered, narrow, the 

 rachilla glabrous and produced beyond the flower, bearing at its apex a small 

 usually awned scale. Scales 4, the 2 lower persistent, narrow, the third scale 

 shortly 2-toothed, bearing a straight awn. 



1. G. ambiguus (Michx.) B.S.P. Stems 3-5 dm. tall: leaf -sheaths with a 

 villous ring at the summit, crowded at the base of the stem; blades 2-10 cm. 

 long, 4-12 mm. wide, crowded at the base: spikes slender, 1-2 dm. long: 

 spikelets 4-5 nun. long, the awn of the flowering scale 4-6 mm. long. — Pinelands. 



31. BOUTELOUA Lag. Erect tufted plants with few scattered many- 

 flowered spikes with the raehis sometimes conspicuously prolonged beyond the 

 spikelets. Spikelets 1-2-flowered. Scales 3 or more, the 2 lower narrow, 

 usually thinner and broader, 3-nerved, the nerves excurrent from the lobes or 

 teeth as short awns, or protruding between the lobes, the small empty scales 

 terminating the rachilla 1-3, 3-awned. 



1. B. oligostachya (Nutt.) Torr. Stems 1.5-5 dm. tall: blades 2-10 cm. long, 

 2 mm. wide or l«^ss : spikes 1-3, 2.5-5 cm. long: spikelets about 6 mm. long. — 

 Pinelands. — Mesquite-grass. 



32. ELEUSINE Gaertn. Annual, or perennial and creeping grasses, with 

 flat leaf -blades, and an inflorescence composed of normally several spikes 

 arranged digitately or approximately with sometimes an additional 1 or 2 

 spikes below. Spikelets numerous, much crowded, imbricate, sessile, alternate 

 in 2 rows, several-flowered, the flowers perfect, or the upper ones staminate. 

 Scales several, obtuse or acute, flattened, keeled, thin, the 2 lower ones empty, 

 a little shorter than the others, the remaining scales usually more obtuse, each 

 of the lower ones enclosing a scarcely shorter compressed 2-keeled palet and a 

 flower, the terminal scales empty. 



1. E. indica (L.) Gaertn. Stems 1.5-6 dm. tall, erect or decumbent: leaf- 

 sheaths loose, overlapping, often short and crowded at the base of the stem; 

 blades 7-30 cm. long, 2-6 mm. wide: spikes 2-10, whorled or approximate at 

 the summit of the stem, or sometimes with 1 or 2 distant ones, 2-S cm. long: 

 spikelets 3-4 mm. long, 3-6-flowered. — Pinelands, cultivated and waste ground. 

 Nat. from the Old World. — F. K. {Ber., Bah., Cuba, Ant.) — Wire-gr.\ss. 

 Dog-grass or Yard-grass. Crow-foot. 



33. DACTYLOCTENIUM Willd. Annual grasses, with flat leaf-blades, 

 and an inflorescence consisting of 1-sided spikes terminally arranged in pairs or 

 digitate. Spikelets numerous, crowded, imbricate, sessile, alternate in 2 rows, 

 several-flowered, the flowers perfect, or the upper ones staminate. Scales 

 several, acute or mucronate-pointed, or the second one awned, thin, flattened, 

 keeled, the 2 lower empty, the remaining scales broader, each of the lower ones 

 enclosing a scarcely shorter compressed 2-keeled palet and a flower, the upper 

 scales empty. 



1. D. aegyptium (L.) Willd. Stems 1.5-6 dm. tall, usually decumbent and 

 extensively creeping: leaf -sheaths loose, overlapping, often crowded; blades 1.5 

 dm. long or less, 2-6 mm. wide, ciliate toward the base: spikes in pairs, or 3-5 



