Pij)er — Andropogon halepensis and Andropogon sorghum,. 27 



Perennial, with extensively creeping white rootstocks 30 to 90 cm. long 

 which jienetrate to a depth of oO to 90 cm., the scaly sheaths about 

 equalling the internodes; culms green except the purple nodes, erect, 

 terete, glabrous or slightly waxy below the nodes, 1-2 meters tall, mostly 

 simple, pubescent only at the more or less constricted nodes; internodes 

 7-9; sheaths smooth or the collar pubescent, those of the culm terete, 

 mostly shorter than the internodes, those of the innovations compressed; 

 blades linear, 30-60 cm. loTig, 10-20 mm. wide, attenuate-acuminate, fiat, 

 the white midvein conspicuous, the margins scabrous ; ligule rounded, 

 1-3 mm. long, ciliolate, ])nbescent on the back, membranaceous; panicle 

 10-40 cm. long, well exserted, erect or suberect, oblong to subpyramidal, 

 rather open, the rachis glabrous except on the scabrous angles; rays 

 mostly in whorls of 2-8 in 5-10 sets, ascending, the longer ones half as 

 long as the panicle, mostly naked for the lower %-%, scabrous on the 

 margins, pubescent at the enlarged base; spikelets usually in threes, often 

 but two, rarely solitary ; central spikelet sessile, perfect, the lower glume 

 convex, with strongly inflexed sides, broadly lanceolate, 4.5 mm. long, 

 1.5-2.2 mm. broad, faintly 5-nerved, chartaceous except the margins 

 near the apex, acute or often obscurely 3-toothed at apex, usually purple 

 tinged, thinly pubescent especially along the margins and toward the 

 base, the back becoming glabrous and shining, the nerves obscure; 

 upper glume narrower, chartaceous, inflexed at the sides, someM'hat 

 keeled, acute, pubescent near the apex, base and margins, partly enclosed 

 by the lower which it equals in length ; sterile lemma one-fourth shorter, 

 hyaline, deltoid-ovate with inflexed sides, truncate, ciliateon the margins, 

 2-nerved: fertile lemma one-half as long as the lower glume, obovate, 

 deeply 2-lobed with diverging lobes, strongly ciliate, bearing from the 

 back near the base a stout geniculate awn 10-15 mm. long; palea a little 

 shorter than the lemma, oblong, obtuse, ciliate, nerveless; anthers yellow, 

 2.5-3 mm. long; stigmas linear, densely plumose, on styles of equal 

 length; caryopsis brownish-yellow, oblong-obovate, 2.5-3 mm. long, 

 convex on the back, the scutellum broadly oval more than one-half as 

 long as the grain ; lateral spikelets staminate, rarely neutral, much nar- 

 rower than the perfect spikelet but of about the same length, borne on 

 very hairy pedicels about half as long as the sessile spikelet; glumes 

 membranaceous, strongly nerved. 



Abundant in the United States, especially south of latitude 37°. Far- 

 ther northward it commonly winterkills. First introduced from Turkey 

 in 1830. 



In the Old World it is native of most of the countries surrounding the 

 ^Mediterranean and eastward to the Himalayas. Herbarium material has 

 been examined from Spain, France, Switzerland, Italy, Hungary, Cilicia, 

 Cyprus, Crete, Greece, Madeira, Canary Islands, Morocco, Algeria, Tunis, 

 Syria, Persia, Afghanistan and the Himalayas. In India it is mostly 

 replaced by A. halepensis miliformis. 



The specimens from Madeira and Morocco have very dark purple 

 spikelets. 



