Saturday, 28 July 2012

Medmenham Meadows

People have had what they wished for - a period of hot weather, useless for long walks but a pleasant enough break in the recent run of cloudy and wet eather. Fortunately the heat has diminished and I braved a walk with the local natural history society trip to Medmenham, which is just over the Thames in Buckinghamshire. For a report on all that the group found please look here. With all the rain the brooks and streams were surrounded by lush, marsh vegetation. We first saw good stands of Hemp Agrimony (Eupatorium cannabinum).

Hemp Agrimony,Eupatorium cannabinum

The concentration was on plants, and fortunately there were several able botanists in the group. Of other creatures the most common must undoubtedly have been grasshoppers. Everywhere you stepped in the meadow, a number of grasshoppers were disturbed and hopped off in every direction. Mostly these were Common Field Grasshoppers (Chorthippus brunneus).

Common Field Grasshopper,Chorthippus brunneus

We saw one or two Ragged Robin (Lychnis flos-cuculi) plants still in flower, indicating a damp, unmolested meadow.

ragged robin,Lychnis flos-cuculi

There were several 'marsh' versions of common plants. Amongst them is Marsh Thistle which has a good proportion of white rather than pink flowers.

Marsh Thistle,Cirsium palustre

Another one is Marsh Valerian (Valeriana dioica)

Marsh Valerian,Valeriana dioica

Growing to an exceptional height of 5 feet 6 inches (1.7m) was Common Figwort (Scrophularia nodosa). Swooping over the fields was a Hobby.

Figwort,Scrophularia nodosa

We then walked along a wooded path with a steep north bank, the bank had many Hart's Tongue ferns (Asplenium scolopendrium). Quite a few had 'split ends' which is an unusual feature for a plant - the central leaf vein can split (bifurcate) into two fronds, sometimes the splits will bifurcate again as in this example.

Hart's Tongue ferns,Asplenium scolopendrium

The ferns were numerous enough as to produce impressive banks.

Hart's Tongue ferns,Asplenium scolopendrium

Along the bank was common but beautiful bellflowers.


The path led along the bottom of a chalk cliff hemmed in by the river Thames on one side, it then turned steeply inland through a tunnel and eventually out into chalk meadow. The presence of Yellow Rattle (Rhinanthus minor) kept the grass in check a bit.

yellow rattle,Rhinanthus minor

Slender knapweed (Centaurea nemoralis) was seen.

Slender Knapweed,Centaurea nemoralis

These days it is the English name that is mainly used for plants, sometimes this is misleading as the name does not make much sense. A case in point is Burnet Saxifrage (Pimpinella saxifraga), which looks nothing like a 'saxifrage' it is actually an umbelifer (carrot family).

Burnet Saxifrage,Pimpinella saxifraga

Now for the non-plant highlight. Among the many insects hopping around in the grass were Roesel's Bush Cricket; it has a characteristic yellow loop behind the head. Like many crickets the antennae are longer than the body.

Roesel's Bush Cricket,Metrioptera roeselii

The final plant of interest was another misnomer, goat's rue which is not like the rue plant at all. Presumably the name came from making the goats that ate it lactate as this is one of the effects of the powerful defence chemicals it contains. In any case it is a member of the large vetch family (Galega officinalis). Not really a 'wild' flower, it is probably a garden escape. Here it had spread over a large area.

Goat's rue,Galega officinalis

Here is the flower close-up, you can see it is a legume with a typical pea flower.

Goat's rue,Galega officinalis