NATURALISTS’ FIELD CLUB

Evening Star, Issue 23382, 27 September 1939, Page 6

NATURALISTS’ FIELD CLUB

NATIVE FIONA One of the commonest of _ native shrubs is the Coprosma, some 17 varieties being listed by the Field Club. At the indoor meeting, Miss H. K. Dalryinple gave some indication of the difficulty of classifying and naming the different species, ami by means of sketches and mounted specimens showed the variations to bo found in this large family of plants. Coprosma, like the coffee plant, belongs to the madder faniilv, and is practically indigenous to New' Zealand, only a few specimens being found in Australia and the Pacific Islands. Coprosmas attract most attention in autumn, when they are covered with innumerable small fruits, the colours of which range from white through cream, yellow, orange, to scarlet, and from pale blue to black. The different species are vary variable in habit, foliage, and vegetative characters, and the difference in colour of the fruits gives no rule for defining the species. One may find the Coprosma growing in any locality, on cliffs by the sea shore, in bush,'or on the edges of bush, in swamps, or on mountains, and it may vary in form from a tall tree to a tiny creeping alpine shrub. Some varieties have large shining leaves with deepseated pits on the backs of the leaves, wliile the smaller-leaved kinds hay© usually a scrubby appearance with branches coming off at very wide angles and widely-separated pairs of small leaves, the' fruits being generally small and round. One species with a very decided odour is called Coprosma foetidissima: another with narrow, small, elongated leaves and bright yellow wood is the mika-mika, while still another common on dry banks has striped blue and white fruits. All the species have certain characteristic features. The flowers are dioecious—that is, one plant bears stanimate or male flowers only, the other pistillate or female. These flowers are very small, greenish grey in colour, so that they are very difficult to see, and they are absolutely destitue of nectar. The stamiuatc flowers are produced in immense numbers. They each have four anthers hanging out of the tiny corolla cups on long, slender filaments, so that they are easily shaken by the "btest breath of wind, and when so disturbed a cloud of extremely fine, dry, and dustv pollen is shaken out of them. The pistillate flowers are usually fewer in number, and are produced close to the branches. The most curious feature about them is the relatively large size of their stigmas, which are from eight to 12 times as long as the corollas. They therefore expose a large surface to the air so as to catch any pollen grains which may be floating about. Flowers of Coprosma may be found at present, and they_ present one -f the best examples of wind-fertilised flowers in the native flora.

OUTING TO BRUCE’S ROCKS. A most interesting time was spent bv a partv of 27 who made the trip to Bruce’s Rocks on Saturday. Solid -rock forms a good -part of the bench here. Tho components of this rock vary in their resistance to the action of the sea, and the resulting channels and pools left when the tide is out make a fascinating field for the study of the abounding plant and animal life in them. Seaweeds of many shapes, sizes, colourings, and textures line the pools, while great masses of kelp fringe the outer edges of the rock platform. Two species attracted special attention, beadlets, composed of straight, upright strings of small graduated bright green beads in pools, and Neptune’s (or mermaid’s necklace), composed of strings of dull, rough, larger beads, and covering large areas of flat -rock about halftide level. Among the seaweeds various forms of animal life were to be noted. Anemones of different colours attracted most notjee Several species of starfish were found, and one most obligingly gave a demonstration of how, when it was turned upside down, it could turn right side up again. Sponges, marine worms, and compound ascidians and some rather small forms of sea life were collected.

Shellfish abounded. Most plentiful, sprinkled on the rocks, were tiny black young periwinkles (Melarhaphe cincta). The largest univalve found was a frog shell (A-rgobucclnura tumida) 3Jiu high. Several specimens of Maurea punctulata uibamor, one of the few red-shelled New Zealand molluscs, were found. More common was the cat’s eye shellfish; it has a green, stony opersulum (or door) which has a -resemblance to a cat’s eye. Several kinds of limpet are to be found clinging to the rock, two being rather prettily marked, one with bands of black and! white with white spots, and the other with white splashes on a green background. Several species of chiton or mail-shell were seen. A single valve of a large lamp-shell was picked up, different from the smaller ones fairly common on the Dunedin beaches. Specimens of the three New Zealand species of sea-ears (Haliotis) and of a slipper limpet were gathered. Over 40 species of shells from Bruce’s Rocks and neighbouring beaches have been listed.