furnished with a distinct footstalk. The plant produces numerous
colourless rhizomes, as thin as threads, which bear minute bladders,
and occasionally swell into tubers, as will [page 432] hereafter be
described. These rhizomes appear exactly like roots, but occasionally
throw up green shoots. They penetrate the earth sometimes to the depth
of more than 2 inches; but when the plant grows as an epiphyte, they
must creep amidst the mosses, roots, decayed bark, &c., with which the
trees of these countries are thickly covered.
As the bladders are attached to the rhizomes, they are necessarily
subterranean. They are produced in extraordinary numbers. One of my
plants, though young, must have borne several hundreds; for a single
branch out of an entangled mass had thirty-two, and another branch,
about 2 inches in length (but with its end and one side branch broken
off), had seventy- three bladders.* The bladders are compressed and
rounded, with the ventral surface, or that between the summit of the
long delicate footstalk and valve, extremely short (fig. 27). They are
colourless and almost as transparent as glass, so that they appear
smaller than they really are, the largest being under the 1/20 of an
inch (1.27 mm.) in its longer diameter. They are formed of rather large
angular cells, at the junctions of which oblong papillae project,
corresponding with those on the surfaces of the bladders of the
previous species. Similar papillae abound on the rhizomes, and even on
the entire leaves, but they are rather broader on the latter. Vessels,
marked with parallel bars instead of by a spiral line, run up the
footstalks, and
* Prof. Oliver has figured a plant of Utricularia Jamesoniana ( Proc.
Linn. Soc. vol. iv. p. 169) having entire leaves and rhizomes, like
those of our present species; but the margins of the terminal halves of
some of the leaves are converted into bladders. This fact clearly
indicates that the bladders on the rhizomes of the present and
following species are modified segments of the leaf; and they are thus
brought into accordance with the bladders attached to the divided and
floating leaves of the aquatic species. [page 433]
just enter the bases of the bladders; but they do not bifurcate and
extend up the dorsal and ventral surfaces, as in the previous species.
368