40 Proceedings of the Biological Society of Washington. 



Andropogon aethiopicus Rupr. ; Steud. Syn. PI. Glum. 1:372. 1854. De- 

 scribed by Steudel from the MSS. name of Ruprecht, based on the 

 same collection as the preceding. 



Andropogon sorghum aethiopicus Hack, in DC. Monogr. Phan. 6:504. 

 1889. Also based on the collection of Kotschy from Mt. Arasch-Cool, 

 Kordofan, the previous descriptions having apparently been overlooked. 

 Hackel describes two subvarieties, namely, longearistatus with awns 

 24-32 mm. long, and breviaristatus with awns 5-15 mm. long, both 

 represented in Kotschy's collections. 



Culms rather stout, glaucous, 10 to 12 mm. in diameter near the inflor- 

 escence and probably much stouter at base ; nodes appressed pubescent; 

 leaves pale green and somewhat glaucous, the blades flat, rather short, 10 

 to 25 cm. long, 10 to 25 mm. broad, glabrous at the collar; panicle ovate 

 to oblong, 10 to 30 cm. long, erect, rather dense, the branches ascending 

 or a little spreading, the longest only one-third the length of the panicle ; 

 lower glume of fertile spikelet 6.5 to 8 mm. long, 3 mm. broad, pale at 

 first at length reddish, densely covered with short silvery appressed pubes- 

 cence, but at maturity more or less glabrate on the back, obscurely 9-11 

 nerved, the nerves evident only near the apex; awns short 5-15 mm. 

 (subvariety breviaristatus Hackel) or long 20 to 30 mm. (subvariety 

 longearistatus Hackel); sterile spikelets lanceolate, sparsely pubescent, 

 strongly 9-nerved, 7 mm. long, the very hairy pedicels only a little 

 shorter; stamens well developed; mature caryopsis not seen. 



Kordofan, Mt. Arasch-Cool, Kotschy No. 158, Oct. 10, 1839 (Berhn. 

 Washington). This is the type of Hackel' s subvariety breviaristatus and 

 almost certainly the same as A . cordofanus Hochst. 



All of the remaining specimens belong to subvariety longearistatus : 

 Kordofan, Mt. Arasch-Cool, iiTo^scTi;/ No. 390, Oct., 1839 (type) (aspecimen 

 of virgatus on this sheet in Kew Herbarium) (Cambridge); Aethiopia, 

 Kotschy No. 132 (Kew): Blue Nile, C. L. Muriel, Aug. 11, 1900. Tall 

 reedy grass 10 ft. high. Arab. "Arda." (Kew); Wadi Eremit, between 

 Suakin and Berber, Schweinfurth No. 655, Oct. 5, 1868 (Berlin) ; Omdur- 

 man. Dr. R. Hartmann, June, 1860 — Abnormal smutted specimen 

 (Berlin). 



The two specimens collected by Hartmann are both abnormal, being 

 infested with smut. They were referred to by Schweinfurth (Plantae 

 Quaedam Niloticae, p. 43, 1862) who considered them referable to Sor- 

 ghum crupina Link. 



This subspecies in its typical form seems confined to upper Egypt in 

 the region surrounding Khartum. It seems much subject to infection by 

 a smut { Sphacelotheca sorghi) which produces an abnormal inflorescence. 



Specimens collected in Sudan by-ff. M. & A. F. Brown No. 1473 (Kew) 

 are very close to typical cordofanus, differing mainly in the shorter awn 

 and the lateral spikelets. Under cultivation in the greenhouse this pro- 

 duces 17-jointed stout culms 2-3 meters high; leaf-blades 50 to 100 cm. 

 long, 3-5 cm. broad; panicle oblong-ovate, rather close, 20-30 cm. long, 

 with ascending branches ; spikelets readily deciduous at maturity ; fertile 



