Thanks Mike

, but I think I have confused myself and everybody else. The image indeed shows what appears to be a Hawthorn stem, because, as you point out, Blackthorns have lateral buds on their thorns
http://www.wildlifeinsight.com/Insight/?p=3563 . However looking again at the original wide image, there are buds on the thorns (and also on the new image that Pauline has just sent me), so these must be Blackthorns!**
Also, for information, the larger, rounder buds may be flowers while the pointy buds should be leaves. I'm not sure if Brown Hairstreak larvae will feed from a flower bud (but I know that other species do). The only way of avoiding flower buds is to take cuttings from a young plant which is not mature enough to produce flowers.
I think it's now just a question of waiting to see what happens.
Vince
**
EDIT** After viewing both species in the wild the following day I have come to the conclusion that this is actually
Hawthorn. It seems that the website link that I posted did not fully explain all the possible variations exhibited by Hawthorn and the similarities it sometimes shares with Blackthorn. The round buds are indeed flower buds, but they also contain developing leaves (Blackthorns have separate flower and leaf buds). The final confirmation was provided by Pauline when I asked her to dissect a round bud and describe the contents. Got there in the end
