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Volume 25, 1892
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Art. XXXVIII.—On a New Insectivorous Plant in New Zealand.

[Read before the Wellington Philosophical Society, 7th December, 1892.]

As is probably well known to all present, we possess in New Zealand several species of Drosera, a group of plants which not only catch insects by means of their tentacles and the viscid matter secreted from their glands, but which, as Darwin has conclusively shown, have likewise the power of dissolving animal matter by the aid of this secretion, which contains an acid, together with a ferment almost identical in nature with pepsin, the matter thus digested being afterwards absorbed into the system of the plant as a means of nourishment. Darwin has fully described other insect-catching plants—Drosophyllum, Roridula, and Byblis effecting the capture by means of their viscid secretion alone, and Dionœa and Aldrovanda through the rapid closing of their leaves. All these carnivorous plants belong to a recognised family known as the Droseraceœ, comprising six well-determined genera.

The New Zealand plant which I desire to bring under your notice to-night is something entirely different. It is a species of fungus belonging to the genus Aseroe, described thus in Hooker's Handbook (vol. ii., p. 616): “A curious genus, the arms of whose pileus somewhat resemble a starfish. Found in New Zealand, Ceylon, and Australia. Volva globose, gela-

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tinous within; pileus stalked, divided at the summit into long radiating simple entire or forked horizontal arms; hymenium at the base of the arms.” The species to which I am about to refer is thus described by the same distinguished botanist:—

Aseroe rubra, Labill., Fl. N. Holl., ii.; Berk., in Fl. N.Z., ii., 187. Two to four inches high; stem as thick as the thumb, even. Rays of the pileus about 8, bright-red, long, subulate, lin.–2in. long, split to the base, continuous with the stem, not divided from them by a deep groove.”

Another species of the same genus, discovered by Mr. Colenso at the Bay of Islands, has been described, and named Aseroe hookeri; but I have never seen it.

There is an excellent coloured drawing of Aseroe rubra in the appendix to the Rev. Richard Taylor's “New Zealand and its Inhabitants” (pl. v., fig. 3).

I have met with this plant in various parts of New Zealand, always in the depth of the woods, its star-like form and bright colour attracting immediate notice. But what I desire to call attention to now is the singular fact (hitherto unrecorded) that this fungus appears to be insectivorous in its habit of life. Its presence is always indicated by a peculiar fœtid smell, like decomposing animal matter, and so pungent in its nature that on handling the plant this very disagreeable odour communicates itself to the fingers, and can only be got rid of by washing the hands in water.

On a recent occasion I found several of them growing in the woods near the Papaitonga Lake; and Mr. Morgan Carkeek, the District Surveyor, who happened to be with me at the time, drew my attention to the fact that each of them had the surface-cup, if I may so term it, completely filled up with the partially-dissolved bodies of dead insects. Mr. Carkeek assured me that during the many years he has spent in the New Zealand forests he has invariably found this plant garnished in a similar manner.

From the interior of the stem a viscid foul-smelling fluid is secreted, and this rises into the cup and mixes with the bodies of moths, flies, beetles, and other small insects collected there, which appear to undergo a process of gradual dissolution and absorption. Now, the question arises, Is this fungus, like the Drosera, a carnivorous plant, and is it endowed with its pungent odour, added to its flower-like brilliancy, for the purpose of attracting its insect-food? And is the fluid itself a solvent, with the acid constituent for aiding the process of digestion? My answer is in the affirmative.

I dissected one of the stems, and found that it was hollow, or nearly so, with what appeared to be a membranous sac at the bottom containing fluid matter; but the examination,

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made on the spot, was necessarily a very hasty and imperfect one.

Since the above was written I have received a letter from Mr. J. Brough, of Nelson (a very observant settler), forwarding me a pressed specimen of the star-like portion of the plant, which I now exhibit, and accompanied by the following note:—

“I wish to bring under your notice a rare fungus I met with some time ago in the locality of Rotoiti Lake. I have never noticed anything of the kind in my travels before. There were six of them, forming a sort of circle. They had the appearance when growing of a flesh-and-blood colour, and several insects and spiders were sticking about each of them. I preserved three of them, and I send you one herewith. Of course it is now dried up, and you merely get the outline, but no doubt this will be sufficient to enable you to send me its botanical name.”