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DUNCAN S. JOHNSON 
C. The stamen, microspore and pollen tube. D. The carpel, fruit, 
ovule and seed. E. The megaspore, embryo sac, embryo and endo- 
sperm. F. Germination. G. Conclusion. 
A. Habit and Vegetative Structure 
Peperomia hispidula A. Dietr. is a small and very delicate Peper- 
omia found (according to deCandolle, Dahlstedt et al.) in Jamaica, 
Costa Rica, Colombia, Ecuador, Brazil and Argentina. It occurs in 
damp mountain forests. In Jamaica it is found on the ridge and north 
side of the Blue Mountains, from i,6oo meters upward. It grows 
among the mosses and ferns, usually in dense shade, on the nearly 
saturated humus of the forest floor. 
The mature plant is small and decumbent, with the terminal 5 or 
6 internodes of each branch assurgent (Swartz 1794, pi. IV). It may 
flower when only 4 or 5 centimeters long, and the largest plants seen 
were rarely more than 10 centimeters in length. The stem is delicate, 
usually whitish or nearly transparent, though, if growing in the light, 
it is sometimes decidedly greenish. It is sparsely branched, and 
cylindrical, except for the two ridges extending down each internode 
downward from the margins of the slightly winged petiole (fig. 10). 
The internodes are from 30 to 40 millimeters long, and i to 1 3^ milli- 
meters in diameter. At each internode are some 15 to 25 multicellular 
bristles, similar to those of the leaf blade to be mentioned below. 
These stiflf, tapering bristles consist of 8 to 12 highly vacuolated, thick- 
walled cells in one longitudinal series, are often a millimeter long and 
have a diameter of 40 ix (figs. 1,2). These trichomes stand out in all 
directions at the node and just above and below it. The stem roots 
freely by groups of 10 or 12 roots formed near the nodes, and more 
rarely by scattered roots along the internodes. These roots are only 
.2 or .3 millimeter in diameter, are but 20 or 30 millimeters long, and 
are sparsely branched. 
The delicate, short petioled, alternately arranged leaves are nearly 
orbicular, though often somewhat cordate at the base. The larger 
ones may be 8 or 10 millimeters in diameter and have petioles 3 or 4 
millimeters long. The petiole is slightly margined at the sides, and 
these two wings end against the dorsal side of the lamina just above 
its base (figs, i, 14). The two basal lobes of the lamina are connected 
with each other by a ridge extending across the anterior face of the 
petiole where it joins the lamina (fig. i). The insertion of the 
