WAYS OF THE WILD.

Auckland Star, Volume LIX, Issue 225, 22 September 1928, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK.

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(By A. T. FT€BOFT.V

Spring associates us with thi ■"••■ - .uM) one of our most beautiful native .'.> .vers. The seed producing flowers in their decline are also beautiful. The ripened seeds are each provided with a long, feathery plume which enable the seeds to be wind-born, and when fallen to the earth are sometimes buried by the action of the wind twirling the plume.

The nine New Zealand species are all confined to this country, and each species has two kinds of flowers—male and female. The clematis is a member of the ranunculus family, and is a climber belonging to a genus of over one hundred species found in most temperate climates. In other lands the flowers are often blue, purple, or yellow.

Laing and Black well state: "Two peculiarities of New Zealand plants are well illustrated by the genus clematis, A large number of our flowers are green and inconspicuous, or at least not brightly coloured, and an unusually large proportion of the species have stamens and pistils on different individuals. There is no doubt that the prevalence >f white in the flora is in some way Hjnnected with the paucity of insects in New Zealand. It also seems probable tjat flies play a larger part in the work of pollination here than they do elsewhere, but too little is known at present about the indigenous species of the lower orders of insects to enable one to speak -definitely about them and their relationship to flowers."

Miss Marguerite Crookes. referring to the large flowers of clematis indivisa in her charming book, "Plant Life in Maoriland." says the scientific reason for the large conspicuous flower is that it is pollinated by insects, and must make itself attractive to secure their visits. The reason why so many of our flowers are green and inconspicuous, is that they are pollinated by the wind, and as it makes no difference to the wind whether they are beautiful or not, they are often very small and insignific!ant. But when Sowers do not use the «m 4 lot fertilisation \»\iT\»oses, but must rely on the visits of certain insects or birds, matters assume a very different aspect.

"It Pays to Advertise." To secure the visits of insects the flower must do two things. It must advertise for a helper; that is to say, it must make its presence known by means of bright colours, large flowers, and sweet scents. Then, having attracted the insects' attention it must make the visit worth while by providing honey, large quantities of pollen or attractive juices of some sort. In some cases we find flowers "make trebly 6ure of securing helpers by being large, brightly coloured, and also fragrant, but jnost flowers are more economical. For instance, among the New Zealand clematis family the largest and loveliest species, clematis indivisa, is both colourless and scentless. On the other hand C. fostida (grossly misnamed) and C. afoliata rely on the production of a powerful scent.

The flowers of -both these species are inconspicuous, those of the former being greenish-yellow and about threequarters of an inch across, while those of the latter are duH purplish and barely half an inch in. diameter.

The best: known species C. indivisa was first collected in 1773 by Forster, in. Queen- Charlotte Sound during Cook's second voyage. "From Forster's time onwards," Cheeseman remarks, "it has been observed by all botanists and explorers, and is now known to be generally distributed in lowland districts from the North Cape to Stewart Island, usually iu bushy places on the outskirts of forests, etc. It ranges from sea level to to 2500 feet."

The Maori name of this plant has been translated as the "Sacred Flower." In the Urewera district, according io Mr. Elsdon Best, the name is spelt Poananga, and is applied to the flowers alone, the stem or entire plant being called Pikiarero. Our name clematis is from the Greek, signifying a vine shoot; it is sometimes called in England, "Virgin's Bower." Another English species is known as "Traveller's Joy." The flowers have no petals, the sepals acting both as protective and attractive organs. The leaves of the young plant are of a very different shape to that of the adult plant; this is the case with many New Zealand plants.

Sensitive Tendrils. The mode of climbing of this and many other species of clematis is through the agency of their highly sensitive petioles, or foot stalk of the leaves, which coil around any twig with which they may be brought in contact. The twining of a tendril is caused by its outer side growing more rapidly than the inner, and thus producing curvature. Miss Crookes describes the method by which the clematis climbs by the stalks of its leaves as follows:—These leaf stalks, like all tendrils, are amazingly sensitive, and if one of them is stroked for.a few minutes with a straw it will gradually bend round and begin to encircle it. When the tendril has once firmly clasped its support, it loses its extreme flexibility and develops internal tissue that makes it stiffer and stronger. The stem of clematis also twines, and as it is sometimes a hundred feet in length, it must, of course, combine extreme strength with extreme flexibility. It is obvious that the arrangement of wood tissues must be quite different from that of an ordinary tree, which must of necessity be strong and rigid to withstand the wind and weather. Now, the clematis obtains ite mechanical success by working on exactly the same principle as do our engineers when making a structure that combines extreme strength with great flexibility. That is to say, the clematis is a successful climber because it uses the cabla method. One difference between an iron cable and, say, a rigid iron pole, is that in the cable the strengthening material is split up into ever so many different strands which are consequently able to slip over each other.

The stem of a typical climbing plant is constructed upon exactly the same principle. If we were to examine a cross section of the stem of clematis under the microscope, we should ee that the strong woody tissue, instead of being arranged in a solid mass, is split up into ever so many strands, united by softer tissue. However, round the outside of the stem we should find a, continuous ring of very strong tissue. The purpose of this ring is to protect the stem from the danger of undue pressure through the growth of itf •upport.