60 SORGHUM. 



AndropogoQ halapensls. — Kunth. 

 Andropogon avanaceus. — Michx. 

 Bluraeiibachia halapensis. — Kohl. 



Bentham, in Genera Plantarum, III, p. 1135, considers the whole genus sor- 

 ghum as comprised in two species, S. vulgare and S. halapense. 



This final conclusion of such eminent authority, is evidence of the plastic 

 nature of this plant, which, by variations, has adapted itself to the various cli- 

 matic conditions under which it is grown, and gives reason to hope that, in the 

 hands of the intelligent cultivator, it may develop other varieties more valuable 

 for the purpose of sugar production than any now known. 



The genus Sorghum (of which Sorghum vulgare is the accepted type) is in- 

 cluded in the natural order Graminacese, to which natural order belongs, also, 

 the tropical sugar-cane (Saccharum officinarum); but it should be remarked 

 that, between the genus Sorghum and the genus Saccharum, there are classed 

 by botanists the three genera, Erianthus, Eriochrysis, and Ischaemopogon. 

 Vid. Grisebach's Flora of the West India Islands, pp. 5G0, 561. 



While, therefore, the two plants are somewhat closely related, this relationship 

 does not warrant the assertion made by a recent writer upon this subject, " that 

 the name sorghum is a mere disguise, for the reason that it is nothing more nor 

 less than a sub-variety of sugar-cane, which may explain why it is that the 

 reader and the investigator have so frequently been misled." 



To the unscientific observer, a growing sorghum plant would seem to combine 

 many of the exterior characteristics of sugar-cane. 



I here append parallel statements, prepared by Dr. George Vasey, Botanist of 

 the U. S. Department of Agriculture, which show the differences between the 

 genera Sorghum and Saccharum, upon which botanists base the opinion that 

 sorghum is not " a sub-variety of sugar-cane.''' 



Sorgimm vulgare. Saccharum officinarum. 



Flowering spikelets, two or three to- The flowering spikelets are placed, 

 gether, on the ends of the branches of at short intervals, on the joints of long, 

 an open panicle; these spikelets are slender branches of the panicle, usu- 

 of two kinds, viz., one sessile, single ally in pairs, one of which is sessile, 

 flowered, fertile spikelet, and accom- and the other pedicellate. They are 

 panying this, one or two others, which each surrounded at the base with a cir- 

 are short stalked, or pediceled, and cle of silky white hairs, which are 

 contain male flowers, or sterile flowers ; longer than the flowers. The spikelets 

 or sometimes these disappear, leaving are usually single flowered ; the sessile 

 only the stalks or pedicels. The fertile one fertile, the upper sometimes male 

 spikelet consists of a pair of thick, only. The glumes are soft and char- 

 coriaceous or hard glumes, and of two taceous, the palets thin and transpa- 

 very thin hyaline palets, one of which rent, and awnless. 

 usually has a twisted awn or beard. The most striking differences be- 

 twice as long as the spikelet. In some tween the two genera, are in the size 

 varieties, the glumes and seed are more and consistence of the flowering or- 

 |or less hairy, and in others nearly gans, in the manner of branching of 

 smooth. The seed is large and round, the panicle, and in the presence in 



Saccharum of the long hairs at the 

 base of the spikelets. 



