Friday, 21 August 2015

Dull Daventry - or is it?

Chris had a dental appointment today and the upshot was that I had about ten minutes to mooch around the car park, just being nosey like.

Now it has to be said that a municipal car park is not among the most exciting of wildlife habitats, coming a little behind the Serengeti - but I made the most of it.

The flowers of Bittersweet show its relationship to
tomatoes and potatoes. Daventry town centre.
21 August, 2015

Shrubs bordered the area and, scrambling through them was Woody Nightshade, aka Bittersweet, Solanum dulcamara. Although fruits were ripening on some plants, others were still producing their rather dramatic flowers. The poisonous nature of the plant  has been much exaggerated, being only moderately harmful, but this does not detract from its interest.
Travellers' Joy aka Old Man's Beard. Daventry town
centre. 21 August, 2015

Also doing its bit of scrambling was our only native clematis, Clematis vitalba. Out in the countryside it is a reasonably good indicator of alkaline soils, but in this habitat it seems content with common or garden border soil. Known as Travellers' Joy, it is, with its woody stems, an unlikely member of the Buttercup Family, Ranunculaceae, but the flower structure is a bit of a giveaway.

The unmistakable trunk of Betula papyrifera.
Daventry town centre. 21 August, 2015

A dozen or so birches had been planted. They lacked the gnarled and fissured trunk of the native Betula pendula, but were specimens of Betula papyrifera, a North American species. This tree, the Paperbark Birch, has become very popular in recent decades.

Birch fruits showing damage by Semudobia betulae.
Daventry town centre. 21 August, 2015

The trunk, the leaves and the shape of the catkins all helped to confirm the identity but I took some catkins and these proved to be of some interest. The perforations in these fruits are the work of a small fly, Semudobia betulae, and the undamaged 'wings' rule out its congener, Semudobia tarda. As far as I am aware this is the first record of this fly attacking Paperbark Birch in Britain.

Another tree nearby was a poplar, with Populus trichocarpa probably being the species in question.

Female 'cones' on poplar. Daventry town centre.
21 August, 2015

This is also a North American tree but its reproductive structures are typical of the genus. It will be seem that the female cone-like catkins are oval and, currently, tightly closed. 

Male catkins on poplar. Daventry town centre.
21 August, 2015

This close-up of the male catkins shows that they are upright and glossy. In spring they will dangle and gape, allowing the wind-borne pollen to escape.

Is it Isochnus sequenii? Poplar leaves, Daventry
town centre. 21 August,2015

The poplar leaves showed some brown blotches, probably the work of a small weevil, Isochnus sequensii. This insect is a relatively recent arrival in Britain and more work may be needed to confirm its identity and relationship to similar weevils.

(A tiny weevil was swept from the foliage but this was Betulapion simile, a seed weevil.)

Well, I reckon my ten minutes was time well spent. So much for 'lifeless' urban environments!

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