558 GRAMINE^. (grass FAMILY.) 



less. Glumes 2, membranaceous, very unequal ; the larger upper one with a 

 spreading awn or tubercle on the back. Palete of the perfect flower membrana- 

 ceous ; the lower one awned below the apex, and densely ciliate on the margins. 

 Stamens 3. Ovary smooth. Styles terminal : stigmas elongated, plumose, with 

 simple hairs. Grain free. 



1. C. Americanum, Spreng. Root pungent ; culm (2° - 3° high) rough, 

 like the narrow leaves; spike at length recurved or coiled (3' -4' long) ; upper 

 glume granular on the back; the stout awn spreading horizontally. (Monocera 

 aromatica. Ell ) — Low pine barrens, Florida to North Carolina. July and 

 Aug. U- 



21. DACTYLOCTENIUM, Willd. Crowfoot-Grass. 



Annual creeping or spreading branching grasses, wifli flat leaves and digitate 

 rarely single spikes. Spikelets 2 - several-flowered, crowded on one side of the 

 flattened rachis ; the uppermost flower imperfect. Glumes 2, compressed-keeled, 

 membranaceous ; the upper (exterior) awn-pointed. Palete 2, boat-shaped, 

 pointed. Stamens 3. Stigmas plumose, with branching hairs. Grain round- 

 ish, rugose, free. 



1. D. ..ffigyptiacum, AViUd. Culms ascending from a creeping base; 

 leaves fringed ; spikes commonly 4, awn-pointed ; spikelets 3-flowered. (Eleu- 

 sine ? cruciata. Ell.) — Cultivated ground, common. Introduced. — Culms nu- 

 merous, 1° high. Spikes 1'- 2' long. 



22. ELEUSINE, Grert. 



Characters chiefly of Dactyloctenium, but the narrower glumes and palesE 

 obtuse and awnless. Stigmas plumose, with simple hairs. Spikelets closely 

 imbricated. — Low annuals. 



1. E. Indica, G«rt. — Cultivated ground, very common. Introduced. 

 Culms (6' -18' high) flattened; leaves flat; spikes 2 -several, the lower ones 

 sometimes scattered (2' -4' long); spikelets 6-flowered. 



23. LEPTOCHLOA, Beauv. 



Flat-leaved grasses, with the numerous spikes disposed in a terminal raceme. 

 Spikelets sessile, loose on one side of the elongated filiform rachis, 3 - many- 

 flowered. Glumes 2, membranaceous, unequal, keeled. Palefe 2, membrana- 

 ceous ; the lower one longer than the upper, 3-nerved, awned or unawned. 

 Stamens 3. Grain oblong, free. 



§ 1. LEPTOCHLOA Proper. — Lower palea unowned. 

 1. L. mucronata, Kunth. Culms 2° -3° high ; sheaths of the broad (4"- 

 6" wide) rough leaves liairy ; spikes numerous, in an elongated raceme, 2' - 4' 

 long, spreading ; spikelets minute, 3 - 4-flowered ; plumes mucronatc, longer or 

 shorter than the flowers : lower palea smooth, emarginate. (Eleusine mucro- 

 nata, Mich.r.) — Cultivated fields, Florida, and northward. Aug. - Sept. ® 



