PANICLE CHARACTERS OF SORGO 27 
as they usually are more distinct than those of the fertile spikelet 
they are somewhat easier to count. The number in the first glume 
varies from about 6 to about 14. In some varieties it ranges ap- 
proximately from 6 to 10 and in others from about 10 to about 14. 
A third class is intermediate, having about 8 to 12 nerves, and the 
greater number of varieties appear to be in the intermediate class. 
The relative distinctness of the venation is somewhat easier to 
determine than the number of nerves, and although there are a num- 
ber of stages or conditions of distinctness which are not sharply 
defined, the extremes, in which the venation is respectively strong 
and weak, show a considerable contrast. In Plate XVI, B, 1 and 2", 
are shown spikelets of two varieties in which nerves are distinct, 
though somewhat less so in the second than in the first; and at B, 3, 
spikelets of a third variety are shown, the venation in these being 
faint. 
The second nerve from each edge of the first glume is frequently 
compressed, and it is usually on the edge of the spikelet as viewed 
dorsally. In some cases these lateral nerves are distinctly coarser 
than the others, and, like those of the fertile spikelet, they are often 
keellike. They are to a greater or less extent scabrous-hispid, and 
there are differences in regard to the coarseness of the minute bristles 
as well as some differences in the length of the latter. The keel of 
the second glume is finely hispid in a greater or less degree, and 
some of the other nerves of the first or second glume are often so to 
some extent in certain varieties. 
PUBESCEXCE 
The sterile spikelet is always barbate at the callus, and the pedicel 
is always ciliate on the angles. The edges of the first glume are 
always ciliate. These types of pubescence are shown in Plate II, D. 
In one or more varieties both glumes are glabrous except at the 
callus and on the edges ; in others they are pubescent, the pubescence 
varying as to abundance and fineness and somewhat as to persistence. 
Color is a somewhat less valuable character in the sterile than in 
the fertile spikelet, the colors usually being duller, there being no 
very sharp contrasts, fluctuations also occurring in tint and shade 
due to fading and to differences in maturity. The extent of the 
coloration is fully as reliable as the color itself, in some varieties the 
spikelets being darkest above and in others darkest at the basal end. 
The pedicel often partakes of the color of the rachis segment, but in 
certain forms it is more highly colored, resembling the fertile spike- 
let, this constituting a rather sharp contrast between certain kinds. 
SPIKELET PABTS 
Certain spikelets show only the two glumes, and others have a 
number of other floral parts, including two lemmas, the palea. and 
the two lodicules. The number of members represented differs with 
the variety, although limits are not sharply marked. Fresh spike- 
lets or those preserved in a liquid can be dissected with little diffi- 
culty, and spikelets from dried specimens can also be separated into 
their distinct members with comparative ease if first soaked in water 
