The little flower buds of blackthorn (Prunus spinosa) look like tiny pearls on the bush and now they are bursting into flower. The blossom appears before the leaves but later then the similar flowers of the cherry plum (Prunus cerasifera) which is less spiny with larger flowers and sometimes mistaken for blackthorn.  Its thorns are very sharp and quite long so suitable for hedging around fields and often used to be used as needles for sewing.  Later the flowers develop into a tiny bitter bluish black plums called sloes which can be used to make sloe gin in late autumn.