40 ‘MISSOURI BOTANICAL GARDEN. 
fleshy, more or less globular, and rootless. Reproductive 
pouch funnel form with its circular opening at the basal 
end of the frond. Spadix of one pistillate and one stami- 
nate flower, bursting through the tissues of the upper sur- 
face of the frond, without spathe ; pistillate flower one 
carpeled and one ovuled; staminate flower of one stamen ; 
anther unilocellate, dehiscing by a slit across the top, the 
two halves opening as reflex valves. 
* More or less flattened above, gibbous beneath, brown punctate, 
WOLFFIA PAPULIFERA 0. sp. 
Fronds slightly unsymmetrical, apparently symmetrical 
to the unaided eye; obliquely broadly ovate in horizontal 
outline; 1 mm. broad by 1-1.5 mm. long; apex rounded; 
upper surface flat at the margin, gradually ascending to 
form asingle prominent large conical papule on the median 
line immediately below the center ; under surface strongly 
gibbous, having the form of the half of a longitudinally 
divided egg; stomata numerous over the entire upper sur- 
face; abundantly punctate with brown epidermal pigment 
cells above, less so beneath. Cells of the upper portion 
small, of the lower large. Floating at the surface with the 
entire upper surface exposed to the air. Flowers and fruit 
unknown.— Thus far found only in Missouri, densely cov- 
ering stagnant pools.— Plate 4 D. 
This species is allied to the Brazilian type, but differs in 
its larger size, proportionately greater width, rounded 
apex, the presence of the large papule, and in the smaller 
number of pigment cells. 
Collected by B. F. Bush, in Varner river, near Kennett, Mo., July, 
1895, and again in quantity by myself (no. 250), at Columbia, Mo., June 
5, 1897. 
WOLFFIA PUNCTATA Grisebach, F]. Brit. W. Ind. Isl. 519. 
1864, 
Fronds symmetrical; elliptical to ovate oblong; .35-.53 
mm. broad by .58-.82 mm. long; upper surface flat or very 
20 
