A Field Notebook: Late summer flowers on the Great Orme

Monday, 19 September 2016

Late summer flowers on the Great Orme

Some really nice late summer flowers on the Great Orme at Llandudno today, and one or two surprises, with some species that I really didn't expect to still be in fllower. Also today still two black redstarts at the copper mines, a single gannet over the sea, 15 common scoter, 4 chough and at least three wheatears.

The first surprise was a few flowers still in bloom of bloody cranesbill. This is one of the most beautiful flowers of limestone regions and it was a delight to see it so late in the year.

Wow! Now this is something special, not because it's a rare plant but because of the location it is growing in. This is common butterwort, its flowers long since over but always a good plant to see. It's insectiverous and you can see some of the small inverts stuck to its leaves. What I really like though is the fact that it is growing in a seepage in the limestone. It was the only plant growing here, and I wonder if it is only capable of living in such a calcareous position because it supplements its diet with insects?

The solubility of limestone in naturally acidic rainwater over millions of years results in the caves, pot holes, underground rivers and grikes often found in limestone regions. Where water runs down or through limestone, organic acid from the soil above increases this action and in caves can form stalactites and stalagmites. The rock in this photos looks like it is melting, and you can see what looks like a mini stalactite forming. The rock here was soft, almost like mud to touch. Look over to the left of the photo and you can see a small butterwort almost covered in the limestone solution!

On the limestone pavement puddles of water gradually eat into the rock until eventually they form deep holes called grikes. These grikes collect debris and soil and the remains of plants and invertebrates, and they're sheltered from the elements and have there own micro-climate. They also provide shelter to plants from grazing animals such as sheep, and it's not surprising therefore that they provide a good habitat for many species, especially ferns. This is black spleenwort, a limestone loving species but one which I had growing in the wall of my house in St Helens due to the lime in the mortar.

A limestone loving umbellifer, burnet-saxifrage. This is another species which grows in St Helens on mortar, or at least it used to. It was in the wall at the side of United Footwear in Carr Mill Road, but since the store closed down I'm not even sure that the wall is still there.

Rock samphire, a limestone loving, coastal umbellifer, it prefers to live close to the sea spray. Notice the fleshy leaves, typical of many coastal species.