A SHOT AT THE END OF SUMMER: do you enjoy surprises? Try the reaction of Touch-me-not. When ripe, the narrow pods are stretched to breaking point and the slightest touch or shock causes them to explode. The seams of the pods can no withstand the strong tension and burst open. The strong pressure is induced by a quantity of sugar solution in the cells of the issue. When ripe the pods are enormous pressure.
When is a Flower Not a Flower ?
The golden disc looks like a splendid flower on top of thickly leaved stem. But it is not. It is great cluster of small florets the sunflower ( Helianthus annuus).
The centre of the tiny, yellow – brown, tube like florets is encircled with yellow, tongue shaped florets. The centre flowers are fertile but the outer florets are infertile.
They are the signals that attract pollinating insects to land.
The tiny florets, grouped together in what seems to be a single flower, ‘co-operate’ in the pollination by insects. The florets bloom gradually from the circumference in towards the centre. The buds of the tubular flowers are open and push out first of all the dark anthers holding the pollen. They attract bees which are usually busily seeking sweet nectar. The bees suck the juice and wipe themselves against the pollen. Further on they find the flowers that bloomed earlier, nearer to the edges. Their stamens have lost their and so they have prepared their styles and stigmas ready to accept the pollen from the young flowers.
The bee that visited the tubular flowers containing nectar and gathered pollen on its body, runs across the capitulum and inadvertently transfers pollen to the prepared stigmas, pollinating the flowers.
The sunflower is such great sun lover that its flowers can be seen turning their faces to the sun as it slowly moves across the sky. It is one the most useful cultivated plants. The plant was grown by the ancient Indian. The Europeans bred this originally ornamental flower to become an immensely productive flower.
No comments:
Post a Comment