312 POACE^. 



a second, sessile or on short stiff straight or curved pedicels, linear, 

 about 3 mm. long; the three glumes softly scabrid with small warts; 

 first empty glume lanceolate, 1-2-3-nerved, often toothed, 2.5 mm. 

 long, second ovate-lanceolate or lanceolate, 3-5-nerved, often 

 toothed, 2-3.5 mm. long; floral glume very thin below, broadly 

 oval, obtuse or truncate, often with very short teeth, 2-5-nerved, 3 

 mm. long; palea oval, hyaline, 2-nerved, 3 mm. long. 



Mexico (Chihuahua), Primjle 1433. 



63. (131). POLYPOGON Desf. Fl. Atl. 1 : GG (1798). Santia 

 Savi, Mem. Soc. Ital. 8c. (VIII.) 2: 479 (1798). RasjxdUa Mem. 

 Soc. Ital. Mod. 8: (3) 479 (1798). Presl, Reliq. Il^nk. 1 : 238, t. 

 40 (1830). Nowodworskija Presl, Eel. Hank. 1 : 238 (1830). 



Spikelets 1-flowered in a dense spikelike or slightly interrupted 

 and spreading panicle, pedicels articulate with a tuft of short hairs 

 above the articulation; empty glumes subequal with a terminal 

 straight awn, floral glume smaller, thinner, usually hyaline, entire 

 or notched, with an awn in the notch or on tlie back, eitlaer twisted 

 and bent at the base, or small and straight or reduced to a minute 

 point. Palea smaller. Stamens 1-3. Styles short, distinct. Grain 

 enclosed but not adherent. 



These grasses are mostly annuals with decumbent bases. The 

 panicle is terminal. There are ten species widely distributed over 

 the globe. Bentham says: "The general structure is almost pre- 

 cisely that of Garnotia in tribe Tristegineas, from which indeed 

 Polypogon only differs in the inflorescence being dense and spikelike, 

 not loosely paniculate." 



A. Awns nearly concealing the spikelets 1, 3 



B. Awns not concealing the spikelets (a) 



a. Empty glumes linear-lanceolate 3 



a. Empty glumes obtuse when spread open 4 



1. P. MONSPELiENSis (L.) Desf. 1. c. Annual Beakd-grass. 

 Alo2Kcurus monspeliensis L. 8p. PI. 89 (1753). 



An erect or geniculate annual, 30-3G cm. high. Sheaths nearly 

 as long as the internodos, the upper slightly inflated; ligule 4-6 

 mm. long; blades flat, soabrid. Spikelike panicle mostly exserted, 

 oval or cylindrical, dense, showing branches more or less, often of a 



