Feeds:
Posts
Comments

Posts Tagged ‘Epipactis’

The Biology of Flowers, Eigil Holm, illustrated by Thomas Bredsdorff and Peter Nielsen (Penguin Nature Guides 1979)

An excellent short introduction to one of the most fascinating areas of biology. Flowers are results of millions of years of interaction between plants and animals. The first animals were insects, the next were birds, and the last so far, at least in nature, were bats. Flight is the important thing, you see, because it allows pollinators to travel far, fast and accurately between individual flowers. To take advantage of wings, plants have evolved to advertise with color, shape and scent, but those advertisements aren’t necessarily honest. Some animals are paid for their services with nectar and pollen, or even with seeds, but others are tricked into cooperating or even turned into drug-addicts.

Helleborines of the genus Epipactis, an orchid named after a plant supposed in ancient times to cure madness, actually induce a kind of madness in the wasps that pollinate them: a wasp sometimes becomes so drunk on Helleborine nectar that “it cannot fly, but walks from flower to flower, covered in pollen clubs” (the helleborine glues a little stick of pollen to the wasp’s head as it drinks the nectar). The wasps can even blunder into spiders’ webs while under the influence or end up too weak to move, caught on the sticky helleborine flower. Apart from bee-orchids, flowers pollinated by bees generally play fair. But bees don’t always play fair back: some flowers are designed for only the heaviest bumblebees to enter, so the lighter “buff-tailed bumble-bee (Bombus terrestris) sometimes steals the nectar by biting holes in the corolla tube” (the base of the flower where nectar is stored).

Talk of “playing fair” is anthropomorphism, of course: selfish genes take whatever advantage they can and if a plant has evolved to feed an animal, it’s because the animal performs some service for it in return. Plants that don’t use animals to reproduce, like the grasses, can seem less interesting at first glance, but if you wait patiently by a field of rye (Secale cereale) in summer, you might change your mind. The dull-looking rye-flowers will be waiting patiently too: for a “sudden lowering of light intensity” caused by a cloud passing in front of the sun, which will trigger the simultaneous opening of thousands of stigmas and a huge cloud of pollen. There’s a lot more to even the dullest-looking flower — and plant — than immediately meets the eye, and this book will give you many mind-expanding examples, beside enriching your understanding of those aspects of flowers that do immediately meet the eye (and nose): their shapes, colors and scents.

Read Full Post »