SORGHUM. Andropogon Sorghum, Brot., or Sor ghum vulgare, Pers. Graminew. Figs. 808-814.
Agriculturally the term sorghum is commonly restricted to the sweet or saccharine varieties.' Botanically the species, Andropogon Sorghum, is held to include all groups of cultivated sorghum, such as the broom-corns, sweet sorghums, kafirs and durras. All other specific names which have been applied to cultivated sorghums are regarded as syn onyms. A. Sorghum is not certainly known in a wild state, and all the cultivated forms referred col ' For this reason the methods of culture and handling given by Mr. Warburton, in the succeeding article, are for the sweet sorghums only. For the methods applicable to the other groups, use and Kafir and Durra, respectively.
lectively to this species are thought to have been derived from the wild .1. Halepensis, Brot. (Figs. 513, 673). This species, well known in the southern states as Johnson-grass, is widely distributed in trop ical and subtropical regions. In Africa and Asia it presents a number of striking forms varying from each other in the same directions as do the chief groups of cultivated forms. A few of the cultivated forms of India are said to be directly traceable to the wild .4. Halepensis. The differences usually cited between the two species are the slender habit, lax open panicle and stout, jointed, perennial rootstocks of A. Halepensis. However, in rich soil A. Halepensis is often more robust than some forms of A. 'Sorghum, as for example, certain kaoliangs from China or some forms of Amber sorghum in this country. The lax, open panicle is also characteristic of Amber sorghum, of some kaoliangs and of some varieties of African origin, as Collier. The stout rootstocks are not possessed by any cultivated variety of sorghum so far as known, though our annual varieties not infrequently become perennial under favorable climatic conditions. Another sepa rating character, emphasized by Hackel, is the jointed pedicel of the spikelet in the wild species and the continuous pedicel in the cultivated species. However, he states that a cultivated form, refer able to A. Sorghum in other characters, was found to have the jointed pedicels of A. Halepensis, thus breaking down the last distinction separating the two so-called species.
Cultivated sorghum is known to have originated in the tropical or subtropical regions of the Old World and to have been many centuries in cultiva tion for human food. From the abundance and diversity of its forms and their very extensive cultivation and use, tropical Africa is generally considered the birthplace of the species. For the
same reasons it may be held to be indigenous to India also. In either case, it was probably culti vated in the Orient long before the beginning of the Christian era.
Botanical description.
Annual grasses, 3-15 feet in height, with stout, erect, jointed stems, 2 inches in diameter, stooling little or much from the base, simple above or producing a single, simple, fruiting branch from each of 1-5 upper nodes, except the uppermost; nodes 7-20 in the forms cultivated in this country; internodes normally longer than or about equaling the sheaths, or sometimes shorter, the sheaths then overlapping, as in kafirs; leaves in two opposite ranks (distichous), large, 1-5 inches in width, 1-3i feet in length, acute at the apex, broadest about the middle, somewhat to considerably narrowed at the base or broad and more or less clasping, depending much on vigor of growth. Peduncles slender or stout, 10-36 inches long, erect or recurved ("goosenecked"). Seed-head a panicle, 5-23 inches in length, of widely different color and shape in different cultivated varieties: a corymb or umbel in form, as in broom-corns, Collier sorghum, and the like ; a true panicle in Amber sorghum, in Shallu and others; a close and spike-like panicle in Orange and Sumac sorghums, kafirs, and others ; and a dense, ovate or globose, head-like panicle in many durras; the rachis or central axis of the panicle greatly shortened in the corym bose forms, as broom-corns, from one-half as long as to equaling the panicle in sweet sorghums, and nearly equaling it in kafir and durra varieties; spikelets in pairs, one sessile, fertile, prominent, the other stalked, sterile, slender, less conspicuous, and falling off readily at maturity; seeds oval, obovate, subglobose or lenticu lar in shape; white, pearly, yel lowish, reddish yellow, red or reddish brown in color ; shorter than the empty glumes (in cluded) or longer (exserted); empty glumes (hulls or outer chaff) usually thick, leathery, much shorter than to longer than the seed, rounded or acute at the apex; normally greenish white while immature, some times remaining so in maturity, in other varieties becoming dif ferent shades of red, brown and black, more or less silky-hairy, at least while young, some forms almost glabrous at ma turity; flowering glume thin, transparent, awned or awnless.