2-9 (-13) mm. broad, flat; panicle 1-6 (-9) cm. long, 8-20 mm. thick, ovoid to 

 subcylindric, glumes 4.2-6.7 mm. long, narrowly winged, as viewed from the side 

 3 or 4 times as long as broad; "sterile florets" subulate, 1.5-2.5 mm. long; fertile 

 floret 3-4.7 mm. long; grain 2-2.3 mm. long. 



Abundant in loamy usually alluvial soils near creeks, in disturbed soils along 

 roadsides and in fallow fields and pastures, in shallow water and in wet sandy 

 edge of ponds and lakes, in Okla. (Waterfall), throughout Tex., common toward 

 the coast, rare in the Trans-Pecos and w. Plains Country, N. M. (Grant Co.) and 

 Ariz. (Graham, Gila and Yavapai to Cochise, Pima and Yuma cos.), spring; Va. 

 to Okla. and s. to the Gulf States; also Ore., Calif., s. Nev., Ariz, and N.M., s. to 

 Son., Chih. and Coah. 



3. Phalaris angusta Trin. 



Tufted annual; culms 55-150 cm. long, 2-6 mm. thick, erect, sparmgly branched 

 in the lower part; ligule a hyaline scale 1-3 mm. long; blades 2-25 cm. long, 3-10 

 mm. broad, flat; panicle 2.5-17 cm. long, 6-15 mm. broad, cylindrical; glumes 

 3-5.5 mm. long, narrowly winged, as viewed from the side nearly 4 times as long 

 as broad; "sterile florets" subulate, 0.7-1.5 mm. long; fertile floret 2.1-3.8 mm. 

 long; grain 1.4-1.6 mm. long. 



Locally abundant in moist loamy soil near and in ditches, creeks and bayous, 

 in s.e. Tex., also Ariz. (Pinal Co.), Mar.-Apr.; Ga. to Tex., w. Ariz., Calif., S. A.; 

 introd. into S. Afr. 



42. Oryza L. 



About 25 species in the Old World tropics and subtropics; we have one. 



1. Oryza sativa L. Rice. Fig. 132. 



Robust annual; culms 6-20 dm. long, 4-20 mm. thick, erect, often rooting from 

 lower nodes; ligule a firm lacerate scale 2-6 mm. long; blades 1-6 dm. long, 4-14 

 mm. broad, flat; inflorescence an open branched drooping panicle 15-40 cm. long, 

 each branch bearing a number of large spikelets; zone of abscission below each 

 spikelet; spikelets sessile or usually on very short pedicels, appressed to the 

 branches, slightly laterally compressed; lowermost parts of spikelets (interpreted 

 either as two sterile lemmas or two glumes) small, lance-subulate, scalelike, 2-3 

 mm. long; fertile floret solitary; lemma and palea fitting closely together, 7-10 

 mm. long, pubescent, brownish, shining, cartilaginous-indurate, the lemma mucro- 

 nate (or in some varieties awned). 



Volunteering in ditches and other muddy and seasonally flooded areas in s.e. 

 Okla. (McCurtain Co.) and s.-cen. and s.e. Tex., late summer-fall; warm parts of 

 the world, indigenous to Old World trop.; in Am. n. to Va. and the Gulf States. 



Economically and for the direct use of mankind this is undoubtedly the single 

 most important plant species in the world. 



43. Leersia Sw. 



Perennials with few slender wiry culms; inflorescences lax open panicles with 

 capillary branches; zone of abscission at the base of the spikelet; spikelets secund 

 along the abaxial sides of the distal portions of the branchlets, overlapping, each 

 consisting of a solitary naked fertile floret (glumes or sterile florets absent), 

 laterally compressed (both lemma and palea keeled), cartilaginous, with obscure 

 or conspicuous nerves. 



About 1 5 species in warmer regions of the world. 



1. Floret only 1 to 1.5 times as long as broad 1. L. lenticularis. 



1. Floret at least twice as long as broad (2) 



2(1). Spikelets 2.5-3 mm. long, closely imbricate and usually parallel with the 

 branches of the panicle 4. L. virginica. 



271 



