58 TlMEHRI. 
covering and quite concealing the still water in which it 
grows. In estates' trenches, ponds and ornamental 
waters, this plant is a pest, from the freedom with which 
it multiplies and the multitudinous number of the indivi- 
duals. The capsules are two to nine in number, or per- 
haps more, about from one to three (sometimes none) of 
each cluster containing macrosporangia. The variety is 
from Cayenne, gathered by PORTEAU and SAGOT, n. 
745, and I have not seen it. 
General distribution — The type from Cuba to Brasil, 
and the var. French Guyana, South Brasil, and Para- 
guay. 
2. Salvinia Radula, Baker, Jour. Bot. Vol. 24 p. 98. — Rhizome 
horizontal, cord or thread-like, 1-2 or more in. 1., branching, puberu- 
lous-scaly. Fronds in pairs, at right angles with the axis, shortly peti- 
oled, rather oblong, rounded, cordate at the base, but not deeply, the 
auricles rounded, ^-fth in. 1., less w., herbaceous, under side pubescent, 
upper striglose, colour metallic-green, veins close, numerous, no fruit 
seen. 
This I gathered (Jenman n. 11 14) in the lake where 
the Victoria regia is growing wild in the forest of an island 
above the falls on the Essequibo River. The rhizome seems 
to extend less than in the preceding species, the leaves are 
more oblong, and the vestiture of the upper surface and 
the veins fewer, and the colour more of a glaucous 
green than in that species. 
General distribution — Guiana to South Brasil. 
Genus II. Azolla, Lam. 
Very small communal floating weeds, branched, with minute imbri- 
cating leaves in a double series, sessile with no veins, a central rib only 
in each, the inferior smaller than the superior, and descending filiform 
simple villous roots, capsules situated in the axils of the leaves beneath, 
of two kinds, membranous, indehiscent ; the larger, globose, containing 
