POACEAE. 29 



broader than the second scale; palet thin or almost hyaline, enclosing a perfect 

 flower, obscurely 2-nerved, scarcely included in the scale which it often slightly 

 exceeds. Stamens 3. Styles elongate. Stigmas 2, thread-like, papillose or 

 shortly plumose. 



1. S. Michauxiana A. Hitchc. Stems 6-18 dm. tall: leaf -blades 3 dm. long or 

 more. 6-1-4 mm. wide: spikes 5-30, 5-13 cm. long: spikelets strongly imbri- 

 cated, 12-14 mm. long, the empty scales strongly hispicl on the keel. — Susque- 

 hanna valley. Common, in wet ground. — Limestones, schists. — Sum. and 

 fall. — Slough-grass. Marsh-grass. 



34. ATHEROPOGON Muhl, Perennial grasses, with narrow flat leaf- 

 blades and an inflorescence composed of numerous scattered short few-flowered 

 spikes. Spikelets 1-flowered, sessile, crowded in 2 rows, imbricated, the rachilla 

 extending beyond the flower, its summit bearing scales or awns. Scales 3 or 

 more, the 2 lower empty, unequal, narrow, acute, keeled, the third scale thinner 

 and broader, 3-toothed at the apex, the teeth more or less awned, enclosing a 

 narrow hyaline 2-toothed palet and a perfect flower, the small upper scales 

 empty, awned. Stamens 3. Styles distinct. Stigmas plumose. 



1. A. curtipendulus (Michx.) Fourn. Stems 3-9 dm. tall: leaf -blades 5-30 

 cm. long, 4 mm. wide or less: spikes 6—16 mm. long, widely spreading or re- 

 flexed: spikelets 4-12, diverging from the rachis, 7-10 mm. long. [Bouteloua 

 racemosa Lag.] — Conestoga and lower Susquehanna valleys. Eare, on dry 

 banks. — • Limestones, schists. — Sum. 



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

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

 ranged digitately or approximately with sometimes an additional single spike 

 below. Spikelets numerous, much crowded, imbricated, 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 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. Stamens 3. Styles distinct. Stigmas plumose. 



1. E. indica (L.) Gaertn. Stems 1.5-6 dm. tall: leaf-blades 7-30 cm. long, 

 2-6 mm. wide: spikes 2-10, 2-8 cm. long: spikelets 3-4 mm. long, 3-6-flowered. 

 — ■ Common, in waste places and on roadsides. Nat. of the Old World. 

 Sum. — Goose-grass. Yard-grass. 



36. TE.IDENS E. & S. Usually perennial grasses, with flat or involute 

 leaf-blades and the inflorescence composed of open or contracted and some- 

 times spike-like panicles. Spikelets 3-many-flowered, the flowers perfect or the 

 upper ones staminate. Scales 5-many, membranous, sometimes firmer, the 2 

 lower empty, keeled, obtuse to acuminate, usually shorter than the rest, some- 

 times longer: flowering scales 3-nerved, the midnerve or all the nerves excurrent, 

 the midnerve and the lateral nerves or the margins pilose, the apex entire or 

 shortly 2-toothed, the teeth obtuse to acute, the callus short and obtuse; palet 

 shorter than the scale, compressed, 2-keeled. Stamens 3. Styles short, dis- 

 tinct. Stigmas plumose. 



1, T. flava (L.) A. Hitchc. Stems 5-16 dm. tall: leaf-blades elongate, the 

 basal and lower ones 2-6 dm. long, 5-15 mm. wide, the uppermost one 6-20 cm. 



