1908] HOLM—SISY RINCHIUM 187 
structure is rather uniform, and the few distinctions which I have 
observed seem to be of merely specific importance. 
Beginning with section BrrmuprANA, the leaf-blade is smooth 
in S. anceps, but furrowed longitudinally in several of the other 
species, as S. angustifolium, S. bellum, etc. The surface varies 
from perfectly glabrous to very prominently scabrous, and it deserves 
Notice that the leaves may exhibit both structures when examined at 
different places. The apex may be very scabrous, for instance, in 
contrast with the lower parts of the blade, or sometimes vice-versa; 
or some of the earliest developed leaves may be more glabrous than 
the succeeding. I mention this since the characters “glabrous” and 
“scabrous” figure so very conspicuously in the recently published 
diagnoses of “new species of Sisyrinchium.” 
The cuticle is thick and distinctly wrinkled. The epidermis is 
frequently thick-walled, especially the outer walls (figs. 13, 15, 20, 21); 
and, as stated above, the extension of epidermis into papillae of 
various forms, pointed or obtuse, is common to several members 
of the genus (fig. 21). 
The stomata are arranged in longitudinal lines on both sides of the 
blade, and they are sunk (fig. 13). It is interesting to notice that in 
the subtropical |S, xerophyllum (from Eustis, Florida) the thickness 
of epidermis reaches its maximum (fig. 15); the cell walls are extremely 
thick and porous, but no papillae were observed in this species. 
In regard to the chlorenchyma, we have in this section a more or 
less typical and compact palisade tissue of several layers, the inner- 
‘Most of which forms circular bands around the mestome bundles, 
with the cells radiating toward the center; while in the peripheral 
(hypodermal) strata the palisade cells are vertical to the epidermis. 
In some species, for instance S. anceps and S. xerophyllum, the 
chlorenchyma breaks down and forms lacunes between the veins, 
especially in the latter species. The mechanical tissue in the genus 
1s only Tepresented by stereome, which accompanies the mestome 
bundles as a small cover on the leptome and hadrome side; but it 
S Not very thick-walled except in S. xerophyllum, and it does 
hot occur as isolated, hypodermal groups in any part of the leaf. 
It occupies the somewhat unusual position of being located inside 
the thin-walled, chlorophyll-bearing parenchyma sheath, which 
