GRAMINEAE. 135 



1. Uniola laxa (L.) B.S.P. SLENDER SPIKE-GRASS. (I. F. f. 451.) Culms 

 4.5-12 dm. tall ; leaves 1.25-4 dm. long, 2-6 mm. wide, usually erect, flat, atten- 

 uate into a long tip, smooth or slightly rough ; panicle spike-like, 1-3 dm. in 

 length, erect, strict, or nodding at the summit, the branches erect, 2.5-5 cm> l n g ; 

 spikelets short-stalked or nearly sessile, 3-6-flowered, about 6 mm. long; flowering 

 scales 3-4 mm. long, acuminate, spreading in fruit ; palet arched, about two-thirds 

 as long as the scale ; stamen I. Sandy soil, L. I. to Penn. and Ky., south to Fla. 

 and Tex., mostly near the coast. Ascends to 270 m. in N. Car. Aug. -Sept. 



2. Uniola latifolia Michx. BROAD-LEAVED SPIKE-GRASS. (I. F. f. 452.) 

 Culms 6-15 dm. tall ; leaves 1-2.25 dm. long, 6-25 mm. wide, flat, narrowed into 

 a somewhat rounded, often ciliate base, acuminate at the apex, smooth, excepting 

 the margins; panicle lax, 1.25-2.5 dm. in length, its branches filiform and pen- 

 dulous, the lower 512.5 cm. long; spikelets many -flowered, oblong to ovate, 1.8-3 

 cm. long, on long capillary pendulous pedicels ; flowering scales 9-12 mm. long, 

 ciliate-hispid on the winged keel ; stamen I. In moist places, Penn. to 111. and 

 Kans., south to Fla. and Tex. Ascends to 600 m. in N. Car. Aug. -Sept. 



3. Uniola paniculata L. SEA OATS. (I. F. f. 453.) Culms 9-24 dm. 

 tall. Leaves 3 dm. long or more, about 6 mm. wide, involute when dry. attenuate 

 into a long slender tip; panicle 2.25-3 dm. in length or more, the branches erect or 

 ascending, strict, rigid, the lower 6-12.5 cm - l n g; spikelets many-flowered, short- 

 pedicelled, ovate to oval when mature, 1.25-2.5 cm. long; flowering scales 8-10 mm. 

 long and scabrous on the keels; stamens 3. In sands of the seacoast, Va. to Fla. 

 and west to Tex. Also in the West Indies and S. Am. Spikelets persistent into 

 the winter. Oct. -Nov. 



83. DISTICHLIS Raf. 



Dioecious grasses, with rigid culms creeping or decumbent at the base, flat or 

 convolute leaves and spike-like paniculate inflorescence. Spikelets flattened, more 

 numerous on the staminate plants than on the pistillate, 6-i6-flowered ; rachilla 

 continuous in the staminate spikelets, articulated in the pistillate. Two lower 

 scales empty, narrow, keeled, acute, shorter than the flowering ones ; flowering 

 scales broader, many-nerved, acute, rigid ; palets 2 -keeled. Stamens 3. Styles 

 thickened at the base, rather long, distinct. Stigmas long-plumose. Grain free, 

 enclosed in the scale and palet. [Greek, signifying two-ranked, probably in refer- 

 ence to the spikelets.] Four known species, natives of America, inhabiting the 

 seacoast or alkaline soil; one of them is also found in Australia. 



I. Distichlis spicata (L.) Greene. MARSH SPIKE-GRASS. (I. F. f. 454.) 

 Culms 7.5-60 cm. tall, erect from a horizontal rootstock, or often decumbent at the 

 base. Sheaths overlapping and often crowded ; leaves 1.25-15 cm. long, 2-4 mm. 

 wide, flat or involute ; panicle dense and spike-like, 1.8-6 cm. in length, the 

 branches 2.5 cm. long or less, erect ; spikelets 6-16 -flowered, 8-18 mm. long, pale 

 green; empty scales acute, the first 1-3 -nerved, two-thirds as long as the 3~5-nerved 

 second one; flowering scales 3-5 mm. long, acute or acuminate. On salt meadows 

 along the Atlantic coast from Me. to Fla., in saline soil throughout the interior, and 

 on the Pacific Coast north to Br. Col. June-Aug. 



84. BRIZA L. 



Annual or perennial grasses, with flat or convolute leaves and open or rarely 

 contracted panicles. Spikelets large, flattened, tumid, many-flowered, nodding, 

 the flowers perfect. Scales thin-membranous, strongly concave, the 2 lower empty, 

 3-5 -nerved, somewhat unequal; flowering scales imbricated, broader than the 

 empty ones, 5-many-nerved; uppermost scales often empty; palets much shorter 

 than the scales, hyaline, 2-keeled or 2-nerved. Stamens 3. Styles distinct. 

 Stigmas plumose. Grain usually free, enclosed in the scale and palet. [Greek 

 name for some grain, perhaps rye.] About 12 species, natives of the Old World 

 and temperate S. Am. 



Perennial ; ligule i mm. long or less, truncate ; spikelets s-i2-flowered, 4-5 mm. long. 



i. B. media. 

 Annual ; ligule 2 mm. long or more, acute ; spikelets 3-6-flowered, 2-3 mm. long. 



2. . minor. 



