Rose Leaf Gall
Having blipped a robin's pincushion gall on a dog-rose a few days ago, here is a different type of gall that I came across.
These galls will have been caused by the larvae of a small wasp - most likely a Diplolepis species.
There are a couple of reasons for being uncertain.
Diplolepis Sp. are known to produce pea galls on the leaves of the dog-rose (Rosa canina) but this is on a Burnet rose (Rosa pimpinellifolia)
On dog-roses, the galls may be smooth or spiked but are found entirely on the upper surface (generally smooth) or entirely on the lower surface (generally spiny). These however, are smooth but one hemisphere is above the plane of the leaf and one hemisphere below. Several galls were seen and they were all the same.
Maybe this species of rose reacts in a different way from the dog-rose. Maybe a different species of wasp is responsible.
Sorry it isn't a well posed composition. I was simply trying to record what I saw and get home before a big black cloud that was looming decided to drop all its water on me.