180 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Rhizomes wanting or short and knotty; blades thin, fiat; empty lemma 1 (2 or 3 

 in U. ornithorhyncha) ; rich or moist woods. 

 Spikelets 8- to 12-flowered on slender pedicels; panicle nodding or drooping. 



_ 2. U. LATIFOLIA. 



'Spikelets 3- to 7-flowered, nearly sessile; panicle erect, nearly simple, the 



branches stiff. 



Spikelets more than 10 mm (usually more than 12 mm) wide, with 5 to 7 



fertile florets. 



Sterile lemma 1; panicle 10 to 15 cm long, the lower branches with 2 to 5 



rather distant spikelets 3. U. nitida. 



Sterile lemmas 2 or 3; panicle 3 to 8 cm long, the branches very short with 



approximate spikelets 4. U. orxithorhyncha. 



Spikelets rarely as much as 8 mm wide at maturity, V-shaped, with 1 to 4 

 fertile florets (rarely more) , and 1 sterile lemma. 

 Collar of sheath pubescent, the sheaths commonly loosely long-pubescent, 



rarely glabrous 5. U. sessiliflora. 



Collar and sheaths glabrous or nearly so. 6. U. laxa. 



1. Uniola paniculata L. Sea oats. (Fig. 356.) Culms stout, 

 about 1 m tall, from extensively creeping rhizomes; blades flat, 



firm, elongate, becoming invo- 

 lute toward the long, fine flexu- 

 ous point; panicle pale, narrow, 

 condensed, heavy and nodding, 

 20 to 40 cm long, the branches 

 arching and drooping, as much 

 as 12 cm long; spikelets very 

 flat, 10- to 20-flowered, mostly 

 2 to 2.5 cm long, 1 cm wide, 

 the first 4 or 5 lemmas empty, 



Figure 357.— Distribution of 

 Uniola paniculata. 



the slender pedicels shorter 

 than the spikelets; lemmas 

 about 9-nerved, strongly com- 

 pressed-keeled, about 1 cm 

 long, acute; palea acute, as long 

 as the lemma, the strong wings 

 of the keels ciliate. % — Sand 

 dunes of the seacoast, Cape 

 Henry to Florida and Texas; 

 northern West Indies; eastern 

 Mexico (fig. 357). 

 2. Uniola latifolia Michx. Broadleaf uniola. (Fig. 358.) Culms 



1 to 1.4 m tall, with short strong rhizomes, forming colonies; 

 blades flat, narrowly lanceolate, 10 to 20 cm long, mostly 1 to 



2 cm wide; panicle open, drooping, 10 to 20 cm long, the branches 

 bearing a few large, very flat spikelets, the pedicels capillary; spike- 

 lets 8- to 12-flowered, 2 to 3.5 cm long, 1 to 1.5 cm wide, green or 

 finally tawny, the first lemma empty; lemmas lanceolate, strongly 

 compressed-keeled, acute, about 1 cm long, striate-nerved, the keel 



Figure 3.56.— Uniola paniculata. Plant, X 1/10; 

 spikelets, X 1. (Kearney 2134, Va.) 



