Plcuraphis. GRAMINE.E. 293 



would iiulicatc, as it extonds from Now Enf^laiul riuite across tlie continent. It is found aloii" 

 nearly tlio wliolo Atlantic coast, usually in brackisli niar.slics, rarely over a foot liif^li. Tlie l'ai° 

 western plant in more luxuriant, and tlic clustered .spikelets give the panicde a denser appearance. 



2. L. imbricata, Thmber, Culms simple, erect, 1 or 2 Icet lii<,'h : leaves 6 to 8 

 inches long, 2 lines wiile at base, setaceously acuminate, slightly scabrous ; sheaths 

 loose: panicle erect, 8 to 10 inches long, usually sheathed at base; spikes very 

 juimerous, solitary or fascicled, sliglitly spreading: spikelets appressed-imbricate, 

 nearly sessile, acute, 7 - 8-llo\vered, about 3 lines long: glumes very unecpial, hispid 

 on the prominent solitary nerve, tlie lower narrow, acute, about half as long as the 

 lowest floret, the ui)per broader, obtuse, mucronate, more than a half longer : lower 

 palet about a line long, herbaceo-membranaceous, minutely 2-toothcd at the obtuse 

 mucronate apex, the lateral nerves long-i)ilose l)elow ; upper palet ecpialling the lower, 

 obtu.se and denticulate at apex and hairy on the nerves : seed loose in the pericarp. 

 — Gram. Mex. Bound, ined. 



Larken's Station, San Diego County (Polvicr, n. 404) ; Fort Yuma (Major Thomas) ; and through 

 the Gila Valley to the Hio Grande. The lower leaves and slieaths are sometimes tinged with 

 purple, tlie panicle usually grayish green. Habit somewhat that of /.. fasricularis, but the spikes 

 are much narrower, the spikelets being .smaller, closely appressed ntul overlapping. In the shaiie 

 of the lower palet tiiey arc very distinct ; in place of tin; acute teeth and manifest awn of the 

 other, the teeth in this are minute and blunt and the midnerve produced only as a mere point. 



31. PLEURAPHIS, Ton-. 



Panicle dense and spikedike. Spikelets in threes at the alternate notches of a 



slender flexuose excavated rhachis, sidjtended by a tuft of hairs. Lateral spikelets 



2 - 3-flowered, starainate ; central spikelet 1 - 2-tlowered, perfect, flattened, broad, 



membranous, with nearly erpial cuneate glumes often 2-cleft at the apex and with 



several (5 to 9) nerves, one or more excurrent below the tip as setoe. Lower palet 



3-5-nerved, cleft and short-awned above; npper 2-nerved and 2-toothed. Stamens 3, 



with short filaments. Scales 2, ligulate, entire. Styles 2, very long, stigraatose with 



simple hairs for the greater part of their length. Lateral spikelets narrow, similar to 



the other in texture. Glumes 2-cleft or entire, 3-5-nerved, awned at or below the 



apex. Palets nearly equal, toothed, the lower 3-nerved, the upper 2-nerved. — Ann. 



Lye. N. York, i. 148, t. 10; Watson, Bot. King. Exped. 381. 



A small genus of perennials, in several works placed with Chloridro', but its relationships are 

 rather with the Puppoplinrcw. For a long time but a .single species was known, but the discovery 

 of another, and perhaps two more, has rendered it nece.s.sary to .so modify the character as to give 

 less importance to the setjB upon the glmnes, which in one jirobable species are nearly muticous. 

 The original species, P. Jamesii, Torr., I. c, common in Nevada and the Hocky Mountain region, 

 and perhafis reaching Northeastern California, lias slemler culms which branch only near the base. 

 In Arizona and westward it is replaced by the species here described, and by P. mulica, Buckl. 



1. P. rigida, Thurber. Culms 2 feet high or more, erect, branching above, solid 

 throughout, clothed, especially within the sheaths, with a dense matted tomentum : 

 lower leaves 4 or 5 inches long, uppermost about an inch, rigid, mostly involute, 

 setaceous-pointed ; ligule very short, lacerate ; sheaths somewhat crowded, upper 

 very loose : panicle 3 or 4 inches long, mostly included at base, pale, tinged with 

 purple : glumes of central spikelet cuneate at base, bilid above, woolly-fringed, 3- or 

 indistinctly 5-nerved, the central nerve excurrent just below the middle as a stout 

 rough divergent awn a little exceeding the glume, the next two produced as setas 

 between the lobes and about equalling them: florets stipitate ; lower palet broad, 

 3-nerved, irregularly 2-toothed and fringed above, tlie awn slightly exceeding the 

 teeth ; upper palet somewhat the longer : glumes of lateral si)ikelets about equalling 

 the florets, irregularly toothed above, one or more nerves terminating as short straight 

 or recurved awns : palets of staminate florets nearly equal, the lower 3nerved and 



