AN AUSTRALIAN CARNIVOROUS PLANT.

Globe, Volume II, Issue 156, 3 December 1874, Page 4

AN AUSTRALIAN CARNIVOROUS PLANT.

The following communication appeared in a recent issue of the Sydney Morning Herald : Sir, —There appeared in the Herald a few days ago a brief notice of the proceedings of the British Association, wherein reference was made to a paper by Dr Hooker on a carnivorous Indian plant named dionaca. This recalled to my mind Hie existence of an Australian plant of similar propensities, but of such small size and so common that it has hitherto been allowed to remain in unmerited obscurity. Whether it is indigenous and peculiar to Australia, or whether it is a modest immigrant from some other land, I know not, but have requested information on this point from Dr Hooker, to whom I have sent this and other specimens by the outgoing mail. It is now nearly nine months since my attention was attracted on the North Shore by a small plant of rosette form, with leaves fringed and covered with hair-like processes, terminating each in a blood-red globule, coated-with a clear bright sparkling gummy exudation, which appeared to be excreted by the red globules. The longest of these hairlike prehensory organs are disposed around the margin of the leaf, in three or more rows. Others much shorter are situated on the surface of the leaf, gradually decreas ■'ng in length as they approach the centre, where they are merely slight protuberances, but each with the red terminating globule,

Pricier a small pocket lens, though there was then no flower, the little plant presented an exceedingly beautiful appearance. Within the last week I have had frequent opportunities of observing the same plant in this neighbourhood, where it is now in flower. The flower stalk, which was only a dry, withered object on my first examination, now exhibits itself two or three inches high, with stalk leaves of the same kind as those just described, and having on the summit a few flowers of a pink or light rose colour, and with buds which under a low magnifying power look like miniature moss roses

On most of these stalk leaves may be observed flies and gnats in various stages of decomposition, and, connecting this fact with the character of the leaf and its powerfully adhesive excretion, it appeared highly probable that we had here a carnivorous, or, more strictly speaking, an insectivorous plant. As a test a few small flics were placed whilst still living on the extremities of some of the outer and longer tentacles, where despite the struggles of the victims, they were securely held by the gummy substance. In fact the desperate struggle of the captives served only to increase the number of their bonds and lessen their chances of escape by bringing them into contact with other tentacles. No further result was immediately apparent, but on re-visiting the spot a few hours later, the flies were found transferred to the central portion of the leaves, where they were held by the adhesion of the short protuberances beneath, and by the pressure of the longer processes or tentacles, which were bent over in a curve. At a still later period the long marginal tentacles had detached themselves from their prey, and resumed their original position—in other cases, where the plants were more advanced in age, the tentacles retained their bent position, or, on recovering from it, became withered. As there was still some doubt whether the flies and gnats had struggled to the centre of the loaves, or whether the tentacles had conveyed them there, this problem was the next to occupy the attention. The solution was soon furnished by the accidental fall of some earth on the tentacles, which were subsequently found to have bent towards the centre of the leaves. In order to confirm the opinion deduced from this occurrence, some very small pieces of beef were placed on the extremities of the tentacles of different leaves. This was done in the forenoon, and on observing the plants four hours later the beef was in every instance found to have been conveyed to the centre, thus affording proof of the power of the prehensory organs to convey the food or whatever adhered to them to the spot where it was decomposed, or digested, or rejected. Of course it is obvious from the size of the plant that only small insects can be captured, the largest not exceeding the bulk of a very small house fly. The insects are held fast until entirely decomposed, the interior and softer parts being the first to disappear, the harder and less digestible portions, such as the wings and head, remaining to the last, and many such remains of the feast will be distinctly visible under the lens, which, without its aid, seem to be a confused black mass.

On some few occasions I have perceived the tentacles in motion when they have not been engaged in holding prey, but the movements were very slow and limited in extent. This beautiful and curious little plant deserves careful examination under the microscope. It is to be found on the sandy borders of small streamlets, and on moist sandy patches where the poverty of a soil composed chiefly of quartz sand, permits but few other plants to thrive. It may be that its insect diet supplies it with those essential elements of nutrition which are not obtainable in its peculiar habitat, and it is thus enabled to flourish where to live would otherwise be difficult or impossible.