80 MISSOURI BOTANICAL GARDEN. 
species had been earlier collected by C. G. Pringle, and 
distributed in his set of 1902 under the manuscript name 
B. unifolia Rose: a fact verified at my return to St. 
Louis, — the distribution number being 8690. 
Aside from its northern distribution for a species of 
the Section Huszia, the rather uncertain source of its 
closest relative, B. monophylla, and the single leaf which, 
like the latter, it produces, B. unifolia is of interest in 
that its single large leaf is closely applied to the rock or 
talus in the crevices of which it is rooted, so that its sub- 
terranean parts are thus given the same kind of protection 
afforded by the similarly appressed basal leaves of the 
stag-horn ferns, Platycerium. 
I am indebted to Dr. Rose for a technical description of 
the species, which has been slightly modified with reference 
to my field notes, and the accompanying detailed draw- 
ings, —the habit illustration being from a photograph 
taken in the Iguala cafion. 
BEGONIA UNIFOLIA Rose, n. sp. 
Tuberous-rooted. Leaf single, lying close upon the ground, sessile, 
nearly orbicular, 10 to 30 cm. broad, with mostly 10 to 12 radiate 
once or twice forked principal veins, deeply cordate with overlapping 
lobes, deltoidly dentate with unequal teeth and frequently shallowly 
and broadly crenate, like the scape loosely white-villous with soft col- 
lapsible hairs that are mostly confined to the veins beneath but are 
scattered over the upper surface, and turn brown in drying. Scape 40 
to 60 cm. high, emerging through the base of the sinus, usually soli- 
tary, at first simple and staminate, later with one or more pistillate 
branches above the middle which are subtended by suborbicular, deeply 
dentate often cuneate bracts sometimes 4 to 6 cm. in diameter: bractlets 
small, persistent, deeply cleft and lacerated. Flowers nearly white, 
glabrous, few at the end of the scape and its branch or branches, on 
slender glabrous or somewhat villous pedicels of about their own 
length. Staminate flowers about 25 mm. in diameter with 2 suborbicular 
often fimbriate sepals and 2 elliptical or spatulate narrower petals; 
stamens many, crowded, with globose-cuneate small anthers much shorter 
than the distinct filaments. Pistillate flowers longer-stalked, with 5 
caducous rather narrow perianth segments scarcely half as long as those 
of the staminate flowers. Fruit 10 to 25 mm. long, 3-celled, with 3 wings, 
of which one is much broader than the others, truncate above, cuneate 
