104 CONTEIBUTIOXS FROM THE NATIONAL HERBARIUM. 



Lemmas awn-pointed Dactyus (p. 128). 



Lemmas pointless. 



Glumes 1 to 3-nerved Poa ( p. 128). 



Glumes 5-nerved or more Distichlis (p. 135). 



Lemmas convex or rounded on the back. 



Lemmas acute or awned Festuca (p. 135). 



Lemmas obtuse and scarious at apex. 



Prominently 5 to 7-nerved Panicularia (p. 139). 



Obscurely 5-nerved Puccinellia (p. 141). 



CHLORIDEAE. 



Pedicel jointed above the persisting glumes; spikes digitate Capriola (p. 146). 



Pedicel jointed below the glumes. 



Spikelets much flattened ; glumes unequal, keeled Spartina (p. 145). 



Spikelets subterete; glumes equal, convex Beckhannia (p. 145). 



HORDEAE. 



Spikelets mostly solitary at each joint of the rachis. 



Spikelet 1-flowered Scribneria ( p. 146). 



Spikelet several-flowered. 



Placed edgewise on the rachis LoLiUM (p. 146). 



Placed flatwise on the rachis Aoropyron (p. 146). 



Spikelets two or more at each joint of the rachis. 



Spikelets 1-flowered Hordeum ( p. 149). 



Spikelets 2 to many-flowered. 



Rachis continuous Elymis ( p. 150). 



Rachis readily separating into joints Sitanion (p. 153). 



HOMALOCENCHRUS. 



1. Homalocenchrus oryzoides (L.) Poll. Hist. PI. Palat. 1: 52. 1776. 

 Leersia oryzoides Sw. Prod. Veg. Ind. Occ. 21. 1788. 

 Phalaris oryzoides L. Sp. PI. 1 : 55. 1753. 



Type locauty: "Habitat in Virginiae paludibusnemorosis." 

 Range: Newfoundland to Washington, south to Florida, Texas, and California. 

 Specimens examined: Seattle, Piper in 1889; North Yakima, Leckenhy, August^ 1897. 

 Zonal distribution: Transition and Upper Sonoran. 



PASPALUM. 



1. Paspalum distichum L. Anioen. Acad. 5: 391. 17.59. 



Type locality: Jamaica. 



Specimens examined: AlongC olumbia River, LedtenJy, October, 1900; Klickitat County, 

 Suksdorf. 



Introduced along the banks of the lower Columbia River. 



SYNTHERISMA. 



1. Syntherisma sanguinale (L.) Nash, Bull. Torr. Club 22: 420. 1895. Crabgrass. 

 Panicum sanguinale L. Sp. PI. 1 : 57. 1753. 

 Digitaria sanguinalis Scop. Fl. Carn. ed. 2. 1 : 52. 1772. 

 Syntherisma praecox Walt. Fl. Car. 76. 1788. 

 Type locality: "Habitat in America, Europa australi." 

 Specimens examined: Pullman, Piper 1920. 

 Sparingly introduced as a weed in grass seed. 



