Piper — Andropogon halepensis and Andropogon sorghum. 33 



(=E1 Egeda) between Khartum and Berber, Schweinfurth No. 529, Oct. 

 20, 1868 (Kew. Berlin); Tedac (?) between Khartum and Berber, 

 Schtveinfurth No. 538, Oct. 19, 1868 (Berlin); Matamma, Gallabat, N. 

 Abyssinia, Schweinfurth No. 1428, Oct. 19, 1865 (Berlin); between Old 

 Dongola and Merowat, Dr. Bronifield No. 32, Feb. 11, 1851 (Kew) "Arab- 

 gerou."; Cairo, Thos. Brown in 1914 (Washington); Cairo, cultivated, 

 B. Q. C. Bolland July 15, 1912 (Kew). 



Exiguus is a very distinct and apparently very uniform subspecies. 

 All of the specimens examined are from Egypt, mostly from the region 

 about Khartum, though Hackel cites a specimen from Senegal. This 

 subspecies has been grown for several years under the name Tunis grass, 

 from seed obtained through Dr. L. Trabut of Algeria, who writes that he 

 secured it originally from Egypt. Under cultivation exiguus crosses 

 naturally with sudanensis and with such cultivated varieties as Amber. 

 The readiness with which virgatus sheds its spikelets does not recommend 

 it for cultivation and there is no reason to believe that any of the culture 

 forms of sorghum are derived from it. 



Andropogon sorghum eichengeri n. subsp. 



Culms slender, not over 3 mm. thick, about 1 meter tall ; leaf-blades 

 bright green, 1-2 cm. broad, 10-20 cm. long; nodes glabrous; panicle 

 erect, very narrow, scarcely exserted, 15-20 cm. long; branches erect, 

 the longest about half the length of the panicle ; fertile spikelets promptly 

 deciduous; lower glumes ovate-lanceolate, acuminate, 7 mm. long, 7-9- 

 nerved, densely covered with appressed silvery hairs; awns 25-27 mm. 

 long; sterile spikelets narrow, glabrous, on very hairy pedicels. 



A very distinct subspecies, collected by Eichenger, No. 3365 (type) at 

 Buiho, German East Africa, in wet places, June, 1911 (Berlin). 



Andropogon sorghum sudanensis n. subsp. 



Culms relatively slender, 2 to 3 meters tall, rarely more than 6 mm. 

 thick, usually many from the same root; nodes 9, appressed-pubescent ; 

 leaf-blades narrow, bright green, 15 to 30 cm. long, 8 to 12 mm. broad, 

 flat or nearly so; panicle erect, ovate-pyramidal 15 to 30 cm. long, about 

 half as broad ; panicle branches slender, flexuous, ascending-spreading, 

 subverticillate in 5 to 8 whorls, the longest about half as long as the 

 panicle, naked for the lower half or third, nearly glabrous at the nodes; 

 lower glume of fertile spikelet elliptic-lanceolate, faintly 11-nerved, cori- 

 aceous, slightly shiny, glabrous except for a few hairs at the base and 

 toward the margin, straw-colored or rarely black when mature, 6 to 7 

 mm. long, 2 to 2.5 mm. broad, slightly constricted above the callus; 

 awns 15 mm. long; sterile spikelets strongly nerved, very narrow, per- 

 sistent, on hairy pedicels nearly as long; caryopsis oval, flattened, 

 orange, 4 mm. long. 



Type specimen grown at Arlington Farm, Virginia, from seed secured 

 from li. Hewison, Esq., Khartum, Anglo-Egyptian Sudan. Mr. Hewison 

 writes that the grass is cultivated under the name garawi. This same 



