10 
BULLETIN 1260, U. S. DEPARTMENT 01 AGRICULTURE. 
plains flora. The mesquite bush and soapweed (Yucca glauca) are 
rather abundant, while the grass covering is thin. The principal 
grasses are blue grama, hairy grama (BouteJoua hirsute), and galleta 
srass (HUaria jamesii). 
SORGHUM GROUPS AND VARIETIES. 
Xo detailed classification of the sorghums will be attempted in this 
bulletin. The main groups and general relationships of the varieties 
are. however, indicated in Figure 5. 
Sorghum. 
;orgo. 
Black Amber. 
Red Amber. 
Orange. 
Sumac. 
Honey. 
Colman. 
Folger. 
Gooseneck, etc. 
Grain sorghum. 
Grass sorghum. 
Broomcorn 
/Sudan grass. 
~\Tunis grass, etc. 
(Standard. 
"\Dwarf. 
Kafir. 
Blackhull. 
White. 
Red. 
Pink. 
Dawn (Dwarf Blackhull . 
Sunrise (Early Blackhull;. 
Yellow. 
Mflo. 
White. 
/Standard. 
\Dwarf. 
/Standard. 
'IDwarf. 
[Standard. 
Feterita < Dwarf. 
(Spur. 
Durra. 
(White 
'\Brown 
Kaoliang (2&5£? 
\Barchet, etc. 
Shallu. 
Fig. 5.— Diagram showing the main groups and general relationship of the varieties of sorghum. 
Owing to the fact that sorghum varieties frequently cross-pollinate 
in the field, new varieties are constantly arising. Such varieties, be- 
ing more or less intermediate in character between the parent vari- 
eties or groups, are difficult to classify. Such supposed hybrids or 
perhaps, in some cases, mutations are represented by the Darso, 
Schrock. and Freed sorghums. Dwarf hegari. although it came di- 
rect from Africa in almost its present form, is intermediate in general 
character between feterita and kafir and shows evidence of hybridi- 
zation. 
Only the most important of the many varieties of sorghum are 
listed in the diagram (fig. 5). In fact although the groups include 
practically all varieties that are grown commercially in the United 
States, they make up but a very small part of the numerous form- 
known to exist in Africa and Asia, the two continents where sorghums 
have been grown from the earliest times. When these numerous 
forms are brought .together for comparison the dividing lines between 
the different groups are found to be very indefinite. Forms with 
white seeds and compact panicles, but having in addition rather 
sweet and juicy stems, seem to belong to the kafir as well as to the 
sorgo group. So, also, the kafirs grade imperceptibly into the durras 
and the durras into the milos and kaoliangs, and forms of the grass 
sorghums are found growing wild in Africa that are nearly as large 
and coarse as the cultivated sorghums. For present purposes, how- 
ever, the simple classification just presented is sufficient. Only the 
two groups, sorgos and grain sorghums, are covered by the experi- 
ments discussed in this bulletin. The grass sorghums arc discussed 
in Bulletin 9S1 (12) of the United States Department of Agriculture 
and the broomcbrns in Farmers' Bulletins 7tis [8 and 958 
