GRASS FAMILY 



107 



1. IMPERATACyrillo, PI. Rar. Neap. 2: 26. /»/. ii. 1792. 



Spikelets all alike, awnless, in pairs, unequally pedicellate on a slender continuous rachis. 

 surrounded by long silky hairs ; glumes about equal, membranaceous ; sterile lemma, fertile 

 lemma and palea thin and hyaline. Perennial slender erect grasses with terminal narrow silky 

 panicles. [Name in honor of the Italian naturalist Ferrante Imperate.] 



About 5 species in the warm regions of the world. Type 

 .species, Lagiinis cylindricns L. , 



1. Imperata hooked Rtipr. 

 Hooker's Imperata. Fig. 218. 



Imperata hookcri Rupr. ; Anderss. Ofv. Svensk. Vet. Akad. Forh. 



12: 160. 1855. 

 Imperata brczifolia Vasey, Bull. Torrey Club 13: 26. 1886. 



Culms erect from creeping rhizomes, 1-1.5 meters 

 tall, glabrous ; sheaths glabrous ; ligule long-villous ; 

 blades elongate, the lower narrowed at the long con- 

 duplicate base, 8-15 mm. wide, acuminate, glabrous, 

 the upper shorter, the uppermost much reduced ; 

 panicle dense. 15-30 cm. long, pale or tawny or some- 

 what rose-tinted, soft, silky ; spikelets about 3 mm. 

 long, clothed with hairs twice as long. 



Desert regions, in the Lower Sonoran Zone; from southern 

 California to western Texas, and south to Jalisco. Sept. -May. 

 Type locality: Texas. 



2. ANDROPOGON L. Sp. PI. 1045. 1753. 



Spikelets in pairs at each node of an articulate rachis, one sessile and perfect, the 

 other pedicellate and staminate. neuter or reduced to the pedicel; glumes of fertile spike 

 let coriaceous, narrow, awnless, the first rounded, flat or concave on the back, several- 

 nerved, the median nerve weak or wanting; sterile lemma shorter than the glumes, empty, 

 hyaline; fertile lemma hyaline, narrow, entire or bifid, usually bearing a bent and twisted 

 awn from the apex or from between the lobes ; palea hyaline, small or wanting ; pedicellate 

 spikelet awnless, sometimes staminate and about as large as the sessile spikelet, sometimes 

 consisting of one or more reduced glumes, sometimes wanting, only the pedicel present. 

 Rather coarse perennial grasses with solid culms, the spikelets in racemes, these (in ours) 

 numerous, aggregate on an exserted peduncle, or single or in pairs, the common peduncle 

 enclosed by a spathe-like sheath, these sheaths clustered, forming a compound inflorescence ; 

 rachis and pedicels of sterile spikelet often villous. [Greek, man-beard.] 



Species about 150 in all warmer parts of the world. Type species, Andropogon virginicus I.. 



Racemes numerous in a pedunculate bractless panicle terminating the culms. 

 Racemes in pairs, subtended by a sheathing bract, forming a compound inflorescence. 



1. A. saccharoidcs. 



2. A. gloineratiis. 



1. Andropogon saccharoides Swartz. 



Pltimed Beard-grass. 



Fig. 210. 



Andropogon saccharoides Swartz, Prodr. Veg. Ind. Occ. 26. 

 1788. 



Andropogon argenteus DC. Cat. Hort. Monsp. 77. 1813. 



Andropogon barbinodis Lag. Gen. & Sp. Nov. 3. 1816. 



Culms tufted, erect or somewhat spreading at base, 

 60-120 cm. high, glabrous except the densely ascending- 

 hispid nodes; sheaths glabrous; blades 3-6 mm. wide, 

 flat, scabrous above, the upper much reduced ; panicle 

 5-8 cm. long, consisting of several appressed or ascend- 

 ing silky-white racemes, somewhat flabellately aggregate 

 at the summit of the culm ; glumes of sessile spikelet 

 5 mm. long, the awn about 2 cm. long, geniculate at the 

 middle, tightly twisted below the bend, loosely twisted 

 above. 



Dry hills in the Transition and Sonoran Zones; from Santa 

 Barbara to San Diego, east to New Mexico and south to the 

 American tropics. Feb. -June. Tyjie locality: Jamaica. 



