SUDAN GRASS AND RELATED PLANTS. 7 



known to exist between Sudan grass and the cultivated varieties of 

 sorghum. Others, no doubt, will be found in Africa when that conti- 

 nent is more carefully explored. No one can foretell the possibilities 

 of improvement through the careful hybridization of these new forms 

 with our cultivated sorghums. 



TUNIS GRASS. 



There have been at least two distinct importations of Tunis grass 

 (Andropogon sorghum virgatus (Hack.) Piper) through the Office of 

 Foreign Seed and Plant Introduction of the Bureau of Plant Industry. 

 The first, S. P. I. No. 26301, was received from Dr. L. Trabut, Algiers, 

 Algeria, December 2, 1909. In a letter received at a subsequent date 

 from Doctor Trabut he says regarding Tunis grass: "This grass has 

 been accidentally introduced at the botanic station with seeds from 

 Egypt, berseem, sorghum, cereals, etc. It has meanwhile become 

 naturalized here." The second importation, S. P. I. No. 38108, was 

 received May 4, 1914, from Alfred Bircher, of the Middle-Egypt 

 Botanic Station, Matania el Saff, Egypt, who described it as " a 

 fodder grass growing spontaneously in Egypt." 



Evidently Tunis grass, like Sudan grass, has been introduced into. 

 Egypt and nO doubt is found growing spontaneously where it has 

 escaped from cultivation. It is native, however, in Anglo-Egyptian 

 Sudan, where it is found growing wild. The Kew and Berlin herbaria 

 contain specimens of Tunis grass from Kordofan, Khartum, El 

 Egeda, between Old Dongola and Merowat, between Khartum and 

 Berber, and at Matama in northern Abyssinia. Hackel cites a 

 specimen from Senegal also. 



Tunis grass has never been tested so extensively as Sudan grass, 

 because it has always appeared less desirable. It is not as leafy as 

 Sudan grass (fig. 5), and its seeds shatter sO easily that a great deal 

 of care is required to obtain a sufficient quantity for field plantings. 

 Scar tissue forms at the base of the seed, and it breaks from the 

 rachis branch clean, like Johnson grass. Much of the seed falls from 

 the top of the panicle before that at the bottom is ripe and while 

 the leaves and stem of the plant are yet green. 



At the Fort Hays Experiment Station, Hays, Kans., in 1914 and 

 1915 Tunis grass made an average yield of 8,360 pounds and Sudan 

 grass 8,840 pounds of cured hay to the acre. The difference in yield 

 is not very large, but the quality of the Tunis grass hay was so in- 

 ferior to that of the Sudan grass hay that further tests were not con- 

 sidered necessary. P. E. Karper, superintendent of substation No. 

 8, Lubbock, Tex., says in Bulletin No. 219 of the Texas Agricultural 

 Experiment Station: " Comparisons of Sudan grass and Tunis 

 grass for forage in 1914 resulted in Sudan grass outyielding the latter 

 in every case, showing a total average increase of yield of 0.85 ton 



