Astudy of some anatomical characters of North American 
Graminex. VI. 
THEO. HOLM. 
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WITH PLATES XXVII AND XXVIII. 
Oryza sativa L. 
The leaf of this grass shows a very great resemblance to 
that of Leersta oryzotdes Swtz. which we have described in a 
previous article upon the leaf-structure of the genus Leersia. ' 
¢ leaf of Oryza (fig. 1) shows the large development of the 
median part, containing not only a mass of colorless paren- 
tyma, but also several mestome bundles on the superior face 
ofthe blade. But it differs by the presence of the large la- 
‘ines, the larger number of mestome bundles on both faces 
{the keel, and the absence of bulliform cells on the inferior 
face of the blade. We remember that in Leersia there was 
oe group of bulliform cells developed on each side of the keel 
® the superior and the inferior face. 
_ Considered by itself, the leaf of Oryza may be character- 
ted as follows: The epidermis, seen en face, represents two 
forms, viz, : strata of short broad cells with undulated radial 
re which cover the mesophyll and in which the stomata are 
° be observed, and strata of long and very narrow cells which 
ver the stereome. A transverse section of these strata (fig. 
eo the narrow lumen of the last mentioned form, that 
| oc lies outside the stereome in contrast to the other one, 
| a & the mesophyll. The bulliform cells (fig. 4) occur only 
ar © Superior face between the mestome bundles, and none 
| : tobe observed above the keel. Epidermal expansions 
‘Vode wmerous, as roundish warts or as curved thorn-shaped 
4&8; the last are confined, however, to the strata outside 
mereome. The stomata seemed to be equally distributed 
“tr ah faces of the leaf-blade, but as stated above, they oc- 
the a. in the strata outside the mesophyll, excepting where 
T iform cells are situated. ae 
~_‘€ Mestome bundles are very variable in size, a fact which 
I 
os Gazerre 17: 358-362. N1892. 
357] 
