Sunday, May 30, 2010
Saturday, May 29, 2010
Saxifrages tend to be associated with mountains - after all their Latin name refers to their habit in growing in rocky crevices - but this species, meadow saxifrage Saxifraga granulata, thrives in grass. It's a declining wild flower but it still has some strongholds up here in North East England, in Teesdale in particular.
Meadow saxifrage has its own distinctive technique for growing and flowering before being shaded out by other vegetation. If it just reproduced from seed it would struggle to compete with grasses but at the end of flowing dozens of tiny buds called bulbils (the 'granules' of granulata), form at the junction of the leaves and stem and when the rest of the plant withers away these sit on the soil surface over the winter. When spring comes they sprout leaves and flowers quickly, stealing a march on the grasses. The flowers still produce large numbers of tiny, widely dispersed seeds and for this they need pollinators, but this particular flower was a potential death trap for an unwary hoverfly visitor.....
... with a spider lurking under the petals, waiting to ambush visitors.
Friday, May 28, 2010
Wednesday, May 26, 2010
Tuesday, May 25, 2010
We encountered this life-and-death struggle between a ground beetle larva and an earthworm that had ventured out of its burrow in Teesdale.
... rolled over on its attacker.....
... and glued it down with sticky mucus.
Saturday, May 22, 2010
Tuesday, May 18, 2010
.... and for small solitary bees like those above. Can anyone help me identify any of these?
It might seem that this is a perfect example of a partnership between plant and pollinator, with generous rewards for services rendered by the insects, but this is a very one-sided relationship. Unlike typical flowers, most dandelions don’t actually need any pollen to set seeds.
Seeds are usually produced when male pollen fertilises a female egg cell inside the flower to produce an embryo inside of the developing seed, but in many dandelion species seeds are produced without the need for fertilisation, so the seedlings are genetic clones of the mother plant. All that pollen and nectar that sustains the bees, as well as the elaborate mechanism for presenting pollen to bees to maximise the chances of cross pollination, is redundant as far as the dandelion is concerned - a needless expense.
This production of seeds without pollination is called apomixis and in recent years it has attracted the interest of genetic engineers, because if it could be enginerred into GM crops they wouldn't require pollen for seed production. This would remove one major objection to these high-tech crops – that they can transfer their genes via pollen to organic crops or wild plant relatives. Without pollen, an apomictic crop could not contaminate non-GM crops, with the added bonus that it could reliably produce seeds without depending on insect pollinators.
Monday, May 17, 2010
Sunday, May 16, 2010
The Durham coast used to be famed for industrial dereliction and coal waste dumping, but thanks to a wonderfully successful clean-up campaign it's now a great place for coastal walking, where you can get eye-to-eye with a kestrel as it glides on the updraft from the beach.