PLANTS OF FRESH WATER, SWAMPS, AND KOi.S. 113 



leaf, it becomes entangled in the sticky fluid, and at the same time 

 the hairs bend over and pin the victim fast. Thus does this tiny 

 but bloodthirsty plant procure some of its nitrogenous food. All 

 this family do not dwell in bogs ; D. auriculata is a plant of the heath, 

 and climbs over grass-stems, &c. D. pygmaea has a remarkable dis- 

 tribution, having so far been found only at the two extremes of New 

 Zealand viz., on the Bluff Hill and in the far north of the North 

 Island. It is a tiny plant, no bigger than one's little-finger nail, and 

 so mav be easilv overlooked. 



*/ / 



Species of the genus Gunnera are frequent in lowland bogs. Those 

 near Invercargill contain abundance of G. prorepens. The New Zea- 

 land species are quite small mere pygmies, indeed, in comparison 

 with their huge-leaved Chilian relation (G. chilensis). But, notwith- 

 standing this, both equally afford house-room to a species of Nostoc, 

 a fresh-water alga, somewhat after the manner of Azolla before de- 

 scribed. Perhaps the prettiest denizen of the bogs is the pale-blue 

 liliaceous Herpolirion novae-zealandiae, which, w T hen not in flower, may 

 be mistaken for a grass. A companion plant is Oreostylidium subu- 

 latum. 



The bog umbrella - fern (Gleichenia dicarpa) frequently occupies 

 large areas of boggy ground, its pale-green leaves and brown stems 

 rendering it very conspicuous. A creeping club-moss (Lt/copodium 

 ramulosum) is frequent in Stewart Island and on the west of the 

 South Island, and farther north the somewhat similar L. laterale is 

 encountered. 



Before leaving the bogs, another flesh-eater must be mentioned, 

 the bladderwort (Utricularia monanthos), a plant with small, showy, 

 purple flowers. The bladderworts are quite without true roots, meta- 

 morphosed leaves functioning as such. In some instances the leaves 

 develop in another abnormal 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 so is digested in due course 

 by the plant. 



