Keston Grasslands

Greater yellow rattle, Rhinanthus angustifolius.
Ravensbourne meadow, 15 June 2011.

Even though I had taken part in a study of Keston's meadows quite recently, I was pleased to see them again. Judy John of the BCS led the walk once again. She knows this common very well, especially its botany.

This time we started at a different spot, by Keston Ponds, and looked at some of the acid grassland nearby before moving across the heath, past Keston Bog, and on to the dry and wet Ravensbourne meadows. Naturally I don't want to repeat what I have already covered, so here are some highlights from this trip.

On the dry grassland where Juncus squarrosus grows, on a poor soil made up of Blackheath gravel, I saw a little butterfly, like a meadow brown but smaller, identified by Judy as a small heath. It was very mobile (kept flying off when I got close) and I only got a partial photo of it, but enough to confirm the identification. It was good to see this; the species is in decline.

We had a closer look at the area around the bog than I took last time. Part of it is still full of white fluffy cottongrass. The small yellow flowers of tormentil were scattered around, and Judy says we should soon see bog asphodel. There were several rushes and sedges; Judy pointed out one new to the bog, Carex demissa, common yellow sedge.

The front of a slowworm, Anguis fragilis, and some cast skin.
Ravensbourne meadow, 15 June 2011

The bog had suffered after Darwin's time from a misplaced attempt to protect it from trampling and depradation by allowing trees to grow up around it, to conceal it. But bog plants such as sundew need light, which was shaded out; a low nutrient environment, ruined by leaf litter; and plenty of water, which was being sucked up by the trees; so the bog fell into a poor state.

Recently, the nearest trees have been removed, and the leaf litter on the sides of the small depression has been scraped off. The old flora are coming back. There are still no sundews, but now that the wet ground surface is exposed again there are other good things, like the sedge mentioned above. But given our generally drier climate, it might never return to being a true valley bog as Darwin saw it.

In the meadows we looked under two of the small corrugated iron shelters and saw several slowworms — many more than we saw on the reptile walk in May. One of the shelters also had a busy ant's nest. The other contained some cast skin, shown in this photo. It's a cropped corner of a rather dark image, and not very clear; I didn't spot this slowworm until I looked at the photo on my computer.

Walking through the woods between the meadows, Judy pointed out specimens of broad buckler fern and male fern by the path. In the wet meadows were the purple flowers of marsh thistles. To one side, a statuesque Italian black poplar tree, not in the best of health.

An Italian black poplar to one side of a meadow. 15 June 2011.

One of the dry meadows had some patches of greater yellow rattle, probably brought in on the machinery used to cut the grass, as we know happened with the corky-fruited water dropwort that came from Jubilee Country Park. On one of the wet meadows, someone had recently camped overnight and had a camp fire, potentially eradicating the black sedge that Judy had been so pleased to find two weeks ago. It takes a lot of work to keep this common in shape and gradually improve it, and it's not always a forward progression.

Back at the ponds, Judy said goodbye and a few of us went off towards the upper car park. At this point I was thinking: Well, I've got some quite interesting photos, but nothing really special. Then a damselfly landed on Sally's arm. I think it was an emerald damselfly, but it's not quite like any of the illustrations in my books, and I will amend this if I am proved wrong. A little further on, we saw where some of the yellow water lilies had been pulled up by someone. One of the flowers was near the bank, floating free in the water. At last, a chance to test whether they really do smell of alcohol! And indeed they do, quite strongly, justifying their alternative common name of brandybottle. The flower was big and fleshy, and the stem was bulky and weak.

Loosely attached to the side of this flower was the exuvium of a damselfly or dragonfly, the empty skin which it had moulted when emerging as an adult. You really can't go far on this common without seeing interesting things, if you watch out for them. Also interesting was a group of people fishing illegally — these ponds are part of the river Ravensbourne, and it was still the close season for coarse river fishing until the end of the day (15th June). Other groups of fishermen by the middle pond were merely reconnoitring and waiting out the day.

Judy John pointing out a sedge new to Keston Bog, Carex demissa, the common yellow sedge.
Keston Bog, 15 June 2011.

Damselfly, possibly an emerald, Lestes sponsa. Keston middle pond, 15 June 2011.

Flower of yellow water lily, Nuphar lutea, aka brandybottle, with damselfly or dragonfly exuvium.
Keston upper pond, 15 June 2011.

Flower of yellow water lily, Nuphar lutea, aka brandybottle, with damselfly or dragonfly exuvium.
Keston upper pond, 15 June 2011.

Fishing out of season. The statutory coarse fish close season applies between 15 March and 15 June inclusive.
This is Keston upper pond, part of the Ravensbourne river, on 15 June 2011.

All the photos in this post were taken with my little Ixus 100 camera.