136 
IOWA ACADEMY OF SCIENCES. 
ANDROPOGON SORGHUM, VAR. HALEPENSE. HACKED. 
(PI. xiii, Fig. 9; PI. xiv, Fig. 11.) 
The epidermal cells (E. C.) in this species have a thick cell 
wall and vary somewhat in size, not as much, however, as in 
some of the other species. Many of the cells, especially the 
larger ones, are somewhat elongated. The cuticle is well 
developed. The bulliform cells (B. C.) vary in number from 
two to four. These gradually blend into the epidermal cells. 
The carene (Car.) consists of five bundles, the large bundles 
of the mid-rib and two smaller closed mestome bundles on each 
side; the bundle next to the mid-rib is very small and without 
stereome. Below the second bundles on each side is found a 
small group of cells. The large central bundle of the carene 
does not differ from those of other species. In this variety the 
leptome (L.) consists of large cells, nearly uniform in size. 
The pitted ducts occur singly; annular duct is rather large. 
The interior of the bundle contains very little stereome. Chlo- 
rophyll-bearing parenchyma cells surround the bundles and are 
average in size. Stereome (Ste.) occurs on upper side of leaf, 
and large bundles are in direct contact with the epidermal cells 
and consist of two quite regular aud distinct layers of cells. 
The uncolored parenchyma cells are large. The lower surface 
of mid-rib in this species is decidedly convex. This is also true 
of M. sorghum, but not so marked. The surfaces of the leaf are 
smooth with the exception of an occasional sharp trichome or 
conical projection which occurs on the upper surface of the 
leaf and only in vicinity of the mid-rib. The usual four types 
of bundles occur. The mestome bundles are not character- 
istic. The cells of the mesophyll (Mes.) directly surrounding 
the bundles are elongated. The bundles on either side of the 
carene occur quite close together. The stereome is confined 
principally in the vicinity of the carene and larger secondary 
bundles. The mesophyll portion does not differ materially from 
that of other species studied. Below stomata (Sto.) occur large 
intercellular spaces. The edges of the leaf contain conspicuous 
cells of stereome. 
COMPARISON. 
A comparison of the species of the genus Andropogon which 
have been studied at this time shows general similarity in ana- 
tomical arrangement of paits, and yet, in each species occur 
characters sufficient to distinguish it. The bundles have the 
same general arrangement and structure, except some minor 
