BLADDERWORTS AND GUNNERAS. 127 
small, showy, purple flowers. The bladderworts are quite without 
true roots, metamorphosed leaves functioning as such. In some 
instances the leaves develop in another unusual way: they construct 
themselves into small bladders, which are furnished with a lid, which 
can open only from without inwards. This leads to an arrangement 
like that of certain mouse-traps, so that a minute aquatic animal may 
easily enter the bladder, whence it cannot escape, and is digested in 
due course by the plant. A beautiful bladderwort (U. delicatula), 
having white flowers with a yellow eye, grows in certain Auckland 
bogs. Another species, U. novae-zelandiae, found in North Island 
bogs generally, has pale-purple flowers with a yellow eye. U. pro- 
trusa and U. Mairi are aquatic species which float on the surface 
of the water; the latter was a plant found only in Lake Roto- 
mahana, but it was destroyed during the Tarawera eruption, nor 
has it been since found either there or in any of the other lakes. 
Species of the genus Gunnera are frequent in lowland bogs. 
Those near Invercargill contain abundance of G. prorepens, which 
forms blackish mats. The New Zealand species of Gunnera are quite 
small—mere pygmies, indeed, in comparison with their huge-leaved 
Chilian relation (G. chilensis) or that giant recently discovered by 
Skottsberg on the Juan Fernandez Group (G. masafuerae) with leaves 
10 feet across. But, notwithstanding this, all equally afford house- 
room to a species of Nostoc, a fresh-water alga, somewhat after the 
manner of Azolla, before described. Perhaps the prettiest denizen 
of these Southland bogs is the pale-blue grass-lily (Herpolirion novae- 
zelandiae), which, when not in flower, may be mistaken for a grass. 
A companion plant is Oreostylidium subulatum,* the only species of 
this purely New Zealand genus. A creeping club-moss (Lycopodium 
ramulosum) is frequent in Stewart Island and on the west of the 
South Island, and farther north the somewhat similar L. laterale is 
encountered. 
Where streams flow through the montane low tussock-grassland 
sphagnum bog of a peculiar kind is common, its presence being at 
once recognized by the general grey colour given by its dominant 
species, a tussock-plant with reddish stems at a close view, the false 
snow-grass (Schoenus pauciflorus). Here, too, in due season, the 
* The species of this paragraph occur in the mountains in many parts of New 
Zealand, 
