Native Wildflowers

Auckland Star, Volume LXVIII, Issue 150, 26 June 1937, Page 6 (Supplement)

Native Wildflowers

[Unfortunately it was foltnd neces-r-.iiy to interpose the article on clinker or hard beech between this art'.ilo and Xo. XIV of the series. K':•<!('!-; who have any difficulty in following the«e notes please refer to the earlier article published on June 12.]

No. XVI.—TINKERING WITH FLAX

By L. M. CRANWELL, MATT HAVE already given you the £ briefest account of our two species of flax, wharariki being the smaller plant, to be seen by the seashore and in the mountains. The commoner and stouter harakeke is Uvs tolerant of cold and exposure. Perhaps it will come as a surprise ti> you to learn that the mountain people of the Urewera could obtain it only by bartering or raiding from their uneasy Bay of Plenty neighbours. Only the tohunga would manage to grow it in some sheltered spot where own "mana"' would make it safe from thieving. Where the Maori women are still working at plaiting and their curious form of weaving, you will find that bleached strips of the root-climbing kiekie, also from the lowlands, are as much used a.i flax, especially for floor mats. These plants do not grow as natives of any country, save Norfolk Island, outside New Zealand, so a first sight of them must have been a real thrill for the early botanists. The Forsters, in 1776, described one species under the name of Phormium, thus making a new genua for the lily family. Since then these plants have become among the chief ornaments of gardens in favourable climates abroad.

In 1912 Dr. Leonard Cockayne reported a probable hybrid between the two species. Other botanists scouted the idea that such crosses occurred.

Xow we come to the work of Dr. H. H. Allan, which has just appeared in the April number of the "Journal of Science and Technology." Dr. Allan, Government botanist, with his assistant, Mr. V. D. Zotov, set out to prove that they could produce hybrids that would mimic the queer forms they had seen in the wild state.

This is what they did, and you could do it yourself if you had the patience to wait some years for your first flowers. They grew a typical clump of wharariki (the little flax) in Feilding in 1927, and as they had

decided to make this the "mother" plant they pinched out all the stamens before the orange pollen could be shed. To protect it from other pollen brought by birds or insects, they covered the flowers, except at the exact moment when they were ready to pop pollen of harakeke (the big fellow) on to the sticky stigmas. Thus they made sure that the next generation would be hybrids. Little seed was set, but this was not unexpected. Four seedlings eventually saw the light of day. and in December, 1935, they flowered for the first time, producing plenty of seed later in the summer. Flax matures rather slowly, so it will be several years before the second generation of seedlings will begin to flower.

And how have the first hybrids behaved? They are all alike,"being intermediate between the parent plants in leaf strength, width of leaf, colour of flower, and so on. In a few respects they are closer to harakeke. which, as you remember, provided the pollen, if you knew of the work of Gregor Mendel, the famous Austrian monk, you could have guessed from the beginning (1) that they would be alike, and (2) that they would come half-way between the parents. Mendel would have called them the IT or "firi*t filial generation." and this term is now always used by plant-breeders. Let me put this simply in the form of a diagram as shown below.

PARENTS.

Xow let your eye follow down the four lines and you will see that in the F2, or "second filial generation,*' there will be three groups emerging. They will be pure plants like the parents (left and rishfi. and hybrids of all grades (in the middle). This ie. what we can predict from the experiment, because Mendel showed us how a certain proportion run true to the parent forms in the second generation, while only the intermediates continue to produrp a mixture of forms. Unfortunately Dr. Allan's experiments may be complicated if foreign pollen comes into the scene. This hybridising 1 business can become very tangled. The main point that flax would cross was proved very easily all the same, wasn't it?