Raindrops helped flowers evolve

Two scientific researchers from the Wuhan University in China have discovered that raindrops may have played a role in the evolution of flowers.

After studying 80 species of flowers living on the university campus, as well as from the nearby Wuhan Botanical Garden, they found that many evolve their shape and structure to prevent their pollen from getting wet. Others, they discovered, dealt with the problem by evolving waterproof pollen, which may explain why flowers in rainy areas have drooping petals or close them when it rains.

Charles Darwin speculated that certain flowers may have evolved traits or structure to protect themselves against the effects of rain, which can wash away pollen grains and dilute the nectar. But, until now, few researchers have done experimental testing in this area.

The scientists realized that humans and animals like to be sheltered when it rains, but wondered how an immobile plant could cope.

First, they recorded how the flowers of each species responded to rainfall; whether the pollen became wet or washed away and the flowers moved or closed their petals. They also measured the effect of rain on the pollen performance, by determining how long the pollen from each species remained viable in water.

The plant 'tanecetum vulgare'. Their findings showed that 20 of the species produced flowers that completely protected their pollen, which meant it was not resistant to water. This supports the theory that flowers can evolve certain structures to keep their pollen dry and viable, to be picked up by pollinators during dry weather.

Other plants, like tulips, shelter the pollen grains by closing their petals rapidly when rain hits them. Some had flowers that would droop downwards, while one species had outlets in its base to let rain drain away.

But 44 species exposed their pollen without any protection, and 13 of these were found to produce pollen that was highly resistant to water, suggesting they had evolved an alternative way to deal with rain.

Research is expected to follow on the protection of nectar from rain on the flowers.

Ants continue to be an issue for many gardeners and just recently, the Toronto Master Gardeners compiled a list of products that are safe and legal to use. There was a lot of confusion when the pesticide ban went into effect, and the only thing I recommend is to check the label of the products listed to be certain they say they are for use in the garden.

These are all boric acid based products for ants that act as a stomach poison and the dry powder can also act as an abrasive to damage the exoskeleton.

Green Earth Homecare ant, roach and crawling insect killer, Wilson roach powder insect dust, Doctor Doom granular bait, Safer's attack ant killer, Later's boric acid dust, The Insect destroyer powder, and Surekiller insect powder can work.

In the past, I've used common tansy (Tanacetum vulgare), a medicinal herb with ferny foliage, as a natural repellent. Although it may not work on all types of ants, it has been successful in the past. Dry the leaves and crumble them, or cut it fresh, to place in and around ant hills as they don't like the scent of it.

Any readers that try an ant product listed above and find it works well can e-mail me, to share their experience so I can pass it along in a future column. E-mail me at lavendercottage.rogers@gm ail.com and visit my blog at http://lavendercottagegardening. blogspot.com.

— With files from the

BBC News