WAYS OF THE WILD.

Auckland Star, Volume LXI, Issue 289, 6 December 1930, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK. A REMARKABLE ROOT PARASITE.

(By A. T. PYCROFT.)

Mr. T. Shout writes from Raetihi asking for information regarding a small plant which he has. Mr. Shout has heard that the name of the plant is dactylanthus and says that when seen on the ground it appears as a solid mass, about the. size of a small football. When boiled .this mass, ha says, is freed of a rubber-like covering and a solid little flower is found attached to the stem of the plant. Mr. Shout states that some specimens which he lias are beautiful and varied and all that he has seen have been taken from the bush at Makatote Viaduct bordering on Tongariro, National Park, at ail altitude of about 2500 feet. Many people in Rafetihi are eager to know something about this queer plant, writes Mr. Shout. This peculiar root parasita has been previously described in this column. It is a remarkable parasitic plant of a very distinct single typo genus which i 3 not closely allied to any other genus and is confined to New Zealand. It was first discovered by Sir Joseph Hooker in 1559. When the Rev. R. Taylor, author of "New Zealand and its Inhabitants," visited England in 1556, he took with him a fragment of the plant which he gave to Hooker, and at Hooker's request Taylor, upon his return to New Zealand, sent a complete specimen from which. Hooker founded the genus dactylanthus wliich is from the Greek meaning finger flowered, in allusion to the finger-like spikes of the flower-heads. The second name of this plant bears the name of its discoverer, Taylor, who found it in 1845, near the head of the Wanganui River, at an estimated altitude of 4000 ft. It was not again met with, after Taylor's later discovery of it in 1857, until 1869, when the late Mr; T. Kirk found it on the Thames range at an altitude of about 1900 ft. Since then it lias been found in various parts of the North Island, as far north as the tableland between the Wairoa and Hokianga. The Flower of Hades.

3 The late Rev. R. Taylor says the - Maoris call this plant pua-o-te-reinga 1 ("flower of Hades") because if. grows t almost buried in the soil. Mr. H. Hill, ' of Napier, who has done so much .to ; increase our knowledge of this plant, i states that the Taupo natives call it E waewae-te-atija ("ghosts' legs"). The r same authority states that the plant is ) truly parasitic for the whole term of its r existence, and that it .never develops i- true roots. Although the dull brown' 1 colour of the flowering stems renders 7 the portion that appears above ground I very inconspicuous, the flowers emit a j strong perfume. Mr. Hill states that 1 lie was enabled to discover the plant i solely through the delicious daphne-like L . fragrance which it emitted, his atten- . tioii being first attracted by the per--3 fume. Mr. Taylor, however, describes f it as,having an earthy and rather un- , pleasant smell. Laing and Blackwell j state that this plant is not one of the , foul smelling or fungoid forms. Miss Crookes, a botanist who has studied this flower, states that should the passer- , by make a close inspection a number of ; thick fleshy shoots several inches high ' would be noticed, consisting of a stalk ' and a grotesque flower-liead, about an inch and a half long and shaped rather like an egg with the top cut off.: The flower-liead contains a number of finger - : like processes bearing minute flowers. , The stems and flower-head are protec- | ted by numbers of small, overlapping j brown scales. ! A Vegetable Storehouse. Now it is impossible for a plant to 1 manufacture food from chemicals in ; the air and water without the assistance of its green colouring matter. Miss Crooke» suggests, to solve this problem, the shoots should be followed to their source an the ground, and if the soil is carefully scraped away we should find that all the shoots sprang from a large warty tuber, which varies in size from a potato to, as Mr. Shout states, the size of a small football. This tuber is a vegetable storehouse providing the shoots with all the food tliey need, just as the potato tuber provides the young potato with nourishment until it can fend for itself, but here the resemblance ends, for if the tuber * is still further examined it will be found to be firmly welded on to the root of some forest tree, from which it received its nourishment. Tho seed is propagated by coming into contact with a suitable root; if it does not find one it dies. Having found a suitable root, a small wart-like swelling will appear. The young plant does not kill the -root, but the parasitic growth affects the root so that its development becomes irregular. The root of dactylantlius apparently grows stronger near the point of attachment, and the older the specimens the more marked this becomes. If the swollen end of the root of the tree at its junction with the parasite is examined it will be seen that in cross section it consists of grooves and ridges radiating from a common centre, into which fitted corresponding grooves and ridges on the underground stem of dactylantlius. This gives the flower-like eifecc mentioned by Mr. Shout. Miss Crookes saj-s the parasite apparently succeeds in deflecting the course of the minute conducting tubes of the tree, so that they pass into the -parasite's own underground stem, and it is thus able to tap the nourishment the root contains. The plant has, in fact, carried on a sort of natural grafting process. When the tuber reaches a suitable size it sends up flower-heads during the flowering sea"son, that is, between February ami April. The llower-hcads contain fingerlike rods, each one bearing a great number of small, very much reduced flowers. On the outside tlie flower-heads are protected by the brown overlapping scales;, inside they are white, brownish, or u curious fleshy pink in colour. It will be seen that the parasite is very specialised. Dactylantlius is only able to succeed in its particular mode of life as a result of a long and complicated series of adaptations. Parasitism moreover, lias its penalties as well as its pleasant and easy side. Dactylantlius has so reduced and modified its structure for parasitic purposes that ifc 1 is quite incapable of any other form of life, and cannot support itself. _ H it cannot find a suitable tree ioot .it dies, and its choice of trees is to some extent limited. The host is usually the pate, hut several other trees arc frequently, attacked.