Tuesday 26 July 2011

Thistly things

There is a great patch of teasels in the open field.

A close-up (left) shows the intricate spiral structure of their flowering heads. (Click on pictures for enlarged copies.)

The other end of the field contains a large stand of burdock (right). The flowers also have their own complex structure.

Both of these plants are members of the thistle family with their flowering heads consisting of a huge number of tiny florets, each containing all the parts found in larger flowers.





The spear thistle (left) is one of the more common members of the family. They usually grow as single specimens, as was this one, at the end of the footpath by the rams' field.

In contrast, the creeping thistle (right) grows in large thickets. They form a continuous clump all along the side of the same footpath.






But why this one is called a thistle I don't know. It's not prickly, has a completely different flower structure and makes quite a pretty picture. It's a blue sow thistle - an invading species from the Caucasus which has escaped from gardens. There's a lovely patch of them at the lower end of Market Field.

It doesn't even have the thistle-like rosettes of leaves at the base that our common British yellow sow thistles have.

I wonder who it was that decided on the name?

Friday 22 July 2011

Dog at the seaside

A trip to the beach at Lancing today. Petra enjoys investigating the vegetation. 

The most common plant is the sea-kale.

But the horned poppy is here in numbers too.

It is very popular with the hover-flies as you can see on the right.

This form of ragwort is also easy to find.I think it is hoary ragwort.The enlarged picture shows the grey down all over.

And a stunted form of bittersweet is flowering well.

Both of these are attractive to the hoverflies too. It's difficult to take a picture without a hoverfly in it! The last two flies shown are the migrant hoverfly - eupeodes corollae. The one on the horned poppy is episyrphus balteatus - the marmalade hoverfly. All three are females and both species are flies that migrate to England from the continent - which is probably why they are here on the beach! Just arrived?

Wednesday 13 July 2011

Ragwort

 

Common Ragwort is one of five "injurious weeds" specified in the Weeds Act 1959. It is said to be one of the most frequent causes of  livestock poisoning in Britain. As such, it should be controlled or eradicated where it might come into contact with farm animals. Unfortunately, this large patch of ragwort is on the footpath next to the rams' field on my walks. I'll see if it gets controlled!

Some free biological control is taking place though. The picture above shows a couple of cardinal beetles which seem to like the ragwort. I don't know if they weaken it, but the cinnabar moth caterpillars in the pictures below certainly do.



The caterpillars feed furiously and the affected ragwort stems get completely consumed. There are scores of caterpillars on this clump of weed but they may not all make it to maturity.

If the ragwort starts to run out, the larger caterpillars are known to feed on the smaller ones.



Where do I Walk?

Mainly in a fairly compact area on the north-east side of Steyning in West Sussex, UK.

For a map of this area see My Home Patch