98 CONTRIBUTION'S FEOM THE NATIONAL HERBARIUM. 



shorter than the lemma, 2-keeled; stamens 3; styles distinct; grain narrow, oblong, 

 free. 



1. Dactylis glomerata L. Sp. PI. 71. 1753. 



Type locality: "Habitat in Europae cultis ruderatis." 



Range: Widely distributed in North America, introduced from Europe and often 

 cultivated. 



New Mexico: Shiprock; Cedar Hill; Chama; Winsors Ranch; Mesilla Valley. 



65. DISTICHLIS Raf. Saltgrass. 



Rigid erect stoloniferous perennial with dense panicles of rather few compressed 

 spikelets; spikelets 8 to 16-flowered, dioecious; glumes carinate, acute, shorter than 

 the lemmas; lemmas broader, 3 to many-nerved, acute, rigid; palea 2-keeled, equal- 

 ing or shorter than the lemmas; stamens in the staminate flower 3; styles thickened 

 at the base, rather long, distinct; grain closely enveloped in the thickened and cori- 

 aceous base of the palea. 



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



Uniola spicata L. Sp. PL 71. 1753. 



Type locality: "Habitat in Americae borealis maritimis." 



Range: Throughout the United States and in Mexico. 



New Mexico: Farmington; Dulce; El Rito; Algodones; Las Palomas; Nambe Val- 

 ley; near Cliff; Rincon; White Sands; Mesilla Valley. Saline soil, in the Lower 

 and Upper Sonoran zones. 



66. POA L. Bluegrass. 



Annuals or perennials with usually flat leaves and with a paniculate inflorescence; 

 spikelets 2 to 6-flowered, the uppermost floret rudimentary; rachilla jointed above 

 the glumes, these herbaceous, lanceolate or ovate, 1 to 3-nerved, keeled, persistent; 

 lemmas herbaceous or membranaceous, lanceolate or ovate, acute or obtuse, awnless, 

 5-nerved, carinate, falling with the 2-keeled palea and a joint of the rachilla, the 

 dorsal or marginal nerves usually soft-hairy and often with a tuft of cobwebby hairs 

 at the base; stamens 3; styles distinct. 



KEY TO THE SPECIES. 



Annuals. 



Plants low, 10 to 20 cm. high; branches of the panicle 



spreading • 1. P. annua. 



Plants taller, 15 to 50 cm. high; branches of the panicle 



erect 2. P. bigelovii. 



Perennials. 



Cobweb at the base of the flowers wanting; spikelets acute 

 at the base; lemmas 5 mm. long or more. 

 Spikelets only slightly compressed; lemmas rounded 

 at the apex. 

 Lemmas merely slightly scabrous; plants bright 



green 11. P. laevigata. 



Lemmas strigose below, scabrous above; plants 



yellowish green 12. P. lucida. 



Spikelets strongly compressed; lemmas acute. 



Ligules long, 5 to 7 mm., acute or acuminate. .13. P. longiligula. 

 Ligules short, less than 5 mm. long, rounded or 

 truncate at the apex. 

 Panicles very narrow and contracted, long- 



peduncled 14. P. longipedunculata. 



