THE COLOUR MYSTERY

Sun (Auckland), Volume II, Issue 382, 16 June 1928, Page 28

THE COLOUR MYSTERY

Colour is the feature which attracts the gardener most in flowers. Without their brilliant petals, flowers would be of little interest and horticulture would appeal to very few if the only colours to be seen in a garden were all shades of green. Exactly how the different hues now exhibited by flowers came to be developed is very much of a mystery at present, but by bringing a little imagination to play, the subject may be illuminated to some extent at least. If we regard the parts of the corollo as having been evolved from foliage leaves, it follows that the earliest blossoms must have been green, as are those of many wind-pollinated plants at the present day. In plants grown under unfavourable conditions the leaves often become sickly and turn yellow and this colour is assumed if insufficient light prevents the chlorophj'll from developing properly. Thus leaves have tended to assume a yellowish tint and in course of time yellow flowers may thus have appeared. This line of reasoning receives some support from the fact that the small flowers of wind-pollinated plants are often yellow. Red may have arisen in the same way as this shade originates in faded leaves in autumn, which turn first yellow and then red and there is no doubt that in the plant world these two colours are closely related, for when a plant which normally bears yellow blooms suddenly “sports’’ blossoms of another colour, the new shade is almost invariably red or orange—the latter being a half-way house, as it were, between the two. Pink, of course, is a weak or diluted form of red, but blue and purple are most difficult to explain. Both colours, are, however, see Din autumn leaves, as well as in the ordinary foliage of such plants as some of the euphorbias and the “red” cabbage. White would result from the total suppression of the green colouring matter, chlorophyll. On this theory, therefore, the earliest flowers were green, yellow being the next to appear, followed by reds and then blues and purples. No. of species White Yellow Rod Blue 20,000 49.13 41.89 33.35 12.9 Mauve Green 9.63 5.4