42 POACEAE. 



in the scale and palet. [Name diminutive of unus, one, of no obvious applica- 

 tion.] About 8 species, natives of America. Type species: Uniola paniculata L. 



Spikelets 12 mm. long or more; inflorescence an open loose panicle. 1. U. paniculata. 

 Spikelets 3-4 mm. long; inflorescence of numerous short secund 



racemes. 2. V. virgata. 



^ 1. Uniola paniculata L. Sp. PI. 71. 1753. 



Culms 1-2.5 m. tall. Leaves 3 dm. long or more, about 6 mm. wide, in- 

 volute when dry, attenuate into a long slender tip; panicle open, loose, 2.25-3 

 dm. in length or more, the branches erect or ascending, strict, rigid, the lower 

 6-12.5 cm. long; 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. 



Sand dunes and beaches, Abaco, New Providence, Eleuthera, Cat Island, Great 

 Ragged Island, Atwood Cay, Crooked Island, Fortune Island, Mariguana, Turk's 

 Islands, Inagua. and Salt Key : Virginia to Florida and Texas ; Cuba. Sea Oats. 

 Catesby 1 : pi. 32. 



2. Uniola virgata (Poir.) Griseb. EL Brit. W. I. 531. 1864. 



Poa virgata Poir. in Lam. Encycl. 5: 78. 1804. 



Uniola racemiflora Trin. Bull. Acad. St. Petersb. 1: 68. 1836; 



Culms tufted, 1-2 m. tall, rigid. Leaves 3-5 dm. long, rigid, involute, 

 usually curved, 2-3 mm. wide; panicle narrow, virgate, 2-5 dm. long, about 

 2 cm. thick, its many short branches erect, appressed, the spikelets racemose- 

 spicate, secund, 3-4 mm. long, oval, few-flowered; flowering scales about 2 

 mm. long. 



Sandy sea-beaches, Abaco, Andros, New Providence, Eleuthera, Cat Island : 

 Oiba ; Hispaniola ; Porto Rico ; Vieques ; St. Thomas ; St. Jan ; Saba. Spike-grass. 



34. DISTICHLIS Eaf. Journ. de Phys. 89: 104. 1819. 



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

 or convolute leaves and spike-like paniculate inflorescence. Spikelets flat- 

 tened, more numerous on the staminate plants than on the pistillate, 6-16-flow- 

 ered; rachilla continuous in the staminate spikelets, articulated in the pistil- 

 late. Two lower scales empty, narrow, keeled, acute, shorter than the flower- 

 ing 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 reference to the spikelets.] Four known species, natives 

 of America, inhabiting the seaeoast or alkaline soil; one of them is also found 

 in Australia. Type species: Uniola spicata L. 



1. Distichlis spicata (L.) Greene, Bull. Cal. Acad. 2: 415. 1887. 



Uniola spicata L. Sp. PL 71. 1753. 



Culms 7.5-60 cm. tall, erect from a horizontal rootstock, or often de- 

 cumbent 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. 



Brackish soil, Andros, New Providence, Eleuthera, Watling's Island, Inagua : 

 Nova Scotia to Washington, California, Texas, and Florida ; Mexico ; Cuba ; South 

 America. Erroneously called Bulrush. Marsh Spike-grass. Rabbit-grass. 



