[Read before the Hawke's Bay Philosophical Society, 13th August, 1907.]
In vol. xxviii of the “Transactions of the New Zealand Institute,” p. 493, there is an article by the late T. Kirk, F.L.S., on Dactylanthus Taylori. It contains all the information which was known up to that time concerning the life-history of this interesting and solitary(?) New Zealand genus of the order Balanophoreæ, which includes a variety of root-parasites. Kerner and Oliver, in their “Natural History of Plants,” vol. i, p. 161, state that “the distinctive property of true parasites resides exclusively in the withdrawal of nutrient substances from the living vegetable or animal bodies which they invade.” Based upon this definition, parasites are classed into three groups, the first including “generally all microscopic forms which live in the interior of human beings and animals, chiefly in the blood”; the second including “fungi possessing mycelia which have the power of withdrawing by the entire surface of their filamentous cells or by clavate outgrowths of the same nutritive material from the tissues of the host invaded by them”; and the third comprising “flowering-plants wherein the seedling upon emerging from the seed penetrates into the host by means of suction roots, or some other part which subserves the function of a suction root, so as to absorb juices from the host.” It is to the latter group that Dactylanthus Taylori belongs.
The order Balanophoreæ contains about forty species, belonging to fourteen genera. They are mostly tropical or subtropical in their distribution over the Old and New Worlds, and are usually found in the deep recesses of the forest.
In the first edition of “New Zealand and its Inhabitants,” by the Rev. R. Taylor, published in 1855, there appears on page 430 a picture of a new plant, “fam. Balanophoreæ,” that is evidently intended to represent the Dactylanthus, but no word is mentioned in the botanical notes about the plant. It may be that Mr. Taylor, at the time when the book was first issued, had merely seen or been shown an imperfect specimen of the plant, as in the second edition, which was issued in 1870, or fifteen years from the time of the first issue, Sir Joseph Hooker's description of the Dactylanthus is given, with several fine illustrations of the plant from specimens supplied by Mr. Taylor.
The claim set up by the Rev. Mr. Taylor as the discoverer of the Dactylanthus has been recently called in question by the son of the late Mr. Francis Williamson, of Wanganui, who writes as follows: “Dear Sir,—The Dactylanthus Taylori was first discovered by the late Francis Williamson, of Wanganui, who arrived in the colony in the early forties. It was found at the root of a Pittosporum tree, at a place called Putotara, a property owned by him. The plant was about the size of a large pine-apple; but, instead of having the top as a pine has, it had five flowerlike stalks, three of which were in bloom, and very sweet-scented. The other two were just buds. My father, being a botanist, knew this to be a new plant, and packed it to send home to England; however, as he heard the Rev. R. Taylor was about leaving for the Old Country, he took the specimen to him, who promised to do him the favour, and to give all particulars as to who found it, &c., Mr. Taylor saying it appeared to be quite a new plant. The next my father heard was that the new plant was named Dactylanthus Taylori.—D. H. Williamson, Havelock N., 30/7/07.”
In Mr. Kirk's paper it is stated that the plant was discovered by the Rev. Richard Taylor, about 1857, growing on the roots of Pittosporum, Fagus, and other trees, at an estimated altitude of 4,000 ft. This may be true as far as Mr. Taylor himself was concerned, as he probably had not seen the plant growing before 1857, although there is a picture of the Dactylanthus flower in his work published in 1855.
“Pua reinga” is the name by which the plant is said to have been known to the Natives; but I have never heard it so called, nor do I understand why it should be known as the leaping, or springing, or jumping flower. When found by me many years ago a Native was with me. The place was Matarau, near to Hicks Bay, beyond the East Cape, and the Native without any hesitation called the plant “wae-wae-atua.” Since then I have found the plant growing in many localities in the deep recesses of the bush, but whenever seen by Natives the same name has been given, and a very old Native of Taupo—Paul Rokino—gave me an old waiata referring to the flower. The name “wae-wae-atua,” or the fingers, the foot, or toes of the atua, seems an appropriate one, for the appearance of a number of fruiting specimens, as shown in Plate XXXI, fig. 1, as they appear above the surface of the ground, generally on the slope of a bank in a deep gully, is curious and strange.
Mr. Kirk, in his notes, gives localities where the plant was first discovered by various collectors. The earliest-known specimens were taken from within the basin of the Wanganui River; but Mr. A. Hamilton, Director of the Dominion Museum, was the first to find specimens along the east coast, at Tarawera, and subsequently at Nuhaka. It has not been observed by myself at the latter place, but in the vicinity of the East Cape and Hicks Bay it is fairly common, the parasite being of very large size. At Matarau many specimens collected were as large as a good-sized cabbage, and the
smell of the flowers in bloom was very sweet. It has been found by Mr. Frank Hutchinson at Hawkestone and Patoka, in the Puketitiri country; and I have found many specimens at Runanga and Opepe, in the Taupo plateau country.
During the past ten years the Dactylanthus has been under fairly close observation by me, and the following notes are the result of inquiries made with living and dead specimens. The specimens in my possession, both wet and dry, are of various sizes. In every instance the rhizome is terminal in respect to the particular portion of the root on which it is found (Plate XXX, fig. 1). Panax and Pittosporum are the only two kinds of trees upon the roots of which it can be stated with certainty that the parasites grow. The ends of the most delicate roots are selected by the parasite. Here a swelling appears, having the appearance of a small wart on the human hand. This is very marked in the smaller specimens, where the host portion can be distinguished from the growing rhizome of the parasite by a smoother surface, a different swelling, and a difference of colour. The swelling at the end of a root host looks as if the tissues had been disturbed and cramped during growth, and near the place of junction the root thickens somewhat, as is clearly shown in Plate XXX, fig. 2. In the latter figure the junction of the rhizome with the host can be seen as flowerlike radiations on the lower part of the rhizome, and by corresponding radiations and depressions at the end of the host root. The latter does not cease to grow after being attacked; in fact, the root appears to grow stronger near the place of attachment with the rhizome, and this becomes more pronounced in the larger and older specimens. When a fresh rhizome is cut into halves so as to trace the root host, the latter, in large specimens, spreads out fanlike and in cuplike depressions, twisted on the outside, and appearing as if the ends of the root had been subjected to great pressure. The depressions or cups are filled mostly with a pithy substance, which, when dry, shrinks and leaves several hollow spaces. On the outside of the terminal roots of the host a similar pithy substance underlies the ordinary bark, and it appears as if the rhizome was fed or nourished in the places indicated.
The rhizome in a growing state presents the appearance of a large potato covered over with warts. When cut through there is a bluish-purple line not unlike that seen in the blue potato, formerly in common use by the Maoris along the east coast. It is not difficult to cut, and resembles a Swedish turnip except in colour. The taste is neutral, or perhaps slightly sweetish, and when bitten is crisp but somewhat dry, and leaves behind a slight raspy or acrid taste. As the flesh portion of the rhizome approaches the cortical layer it is covered over with pimple-like growths. These eventually push their way through a mass of cortical layer, and form flowering-shoots over the entire surface of the rhizome. If the tubercular growths which cover a rhizome-like wart be cut across, they show a distinct arrangement of parts. First come the scales, then a yellowish-white band made up of strands resembling resin. Within this, but touching the inner portion, are ten or twelve horseshoe-like forms, some of a rich orange colour and others a deep purple; but they always present one or other of these characteristics. If the two ends of a horseshoe were joined loosely so as to bend inwards somewhat, the similarity would be complete. I have cut many of the fresh growing tubercles, and have separated the scales one by one so as to get at the central growing portion. This consists of minute growths, not unlike in appearance one of the ripening flowers of a fig, except that each part is made up of two lip-like growths, one being a little larger than the
other. It would seem that the purple tubercles give rise to the female spadices, and the orange to the male. They certainly present similar appearances to what are seen in the complete flowers.
The female peduncle is usually shorter than the male, but each varies in size according to conditions of growth and development. The pistillate flowers surround each spadix. They are very small, are less numerous below, and increase in number upwards, although fewer seeds mature at the top than below. The flower is of two parts, forming a closely fitting perianth as the ends appear above the ovary, and, like the pistil, are permanent, and can be seen in the ripened fruit, as illustrated in Plate XXXII, fig. 2. The lower part of the perianth is pale yellow, the upper purple, as are likewise the style and stigma. As the seed ripens the ovary swells somewhat, and when ripe the yellow part has changed to a bluish-green, that passes above into a deep purple. This has reference to the perianth only, for when the covering is removed a tiny nut of a deep-purple colour is seen, and within this nut there occurs a white structureless substance like wax.
The male or staminate flowers have a peduncle that is similar to that of the female, except that it is larger, as are likewise the scales. As the flower expands the scales are symmetrical, and the whole when fully developed is ringent and not unlike a small dahlia (Plate XXXII, fig. 1). The colour of the surrounding scales varies from a straw-yellow in the outer whorl to a deep orange with purple stripes in the case of the petal-like scales that surround the spadices. The latter vary in number from 16 to 28. About each spadix staminate flowers wind from left to right. They are connected with the spadix by short filamentary attachments. Each staminate flower is of a yellowish-grey colour, fleshy, and presenting the appearance of a tiny disc, with a deep depression running from top to bottom. The pollen appears to be developed along the margin of the anther, and is abundant. As soon as the spadices are fully developed the scales fall back, and the flower eventually dies down and falls off.
The flowering takes place between February and April. Until Easter Monday, 1907, I had not seen a male flower in full bloom. Plate XXXII, fig. 1, shows a male flower just opening. As the development of the flower proceeds the scales droop, and the spadices present a straggling appearance.
I have made numerous experiments both with rhizomes and seed, but up to the present time the results have not been satisfactory.