A vocabulary of landscape — a landscape of words 1190 entries

blackthorn

BLAK-thorn
Prunus spinosa, a dense armored shrub that flowers white on bare black wood before any leaf appears, then carries small blue-black fruit — sloes — into autumn. The thorns are hardened side shoots and they are serious.
Etymology
Old English, and exactly what it says: blæc plus þorn, named against hawthorn or whitethorn, its opposite number in the hedge. The distinction is in the bark, which is near-black on this and pale grey on hawthorn, and the two flower a month or more apart, so a hedgerow tells you the date. Sloe is the older word for the fruit, Old English slāh, from a Germanic root shared with Dutch slee and German Schlehe, thought to trace back to a sense of blue.
Notes
Sloes are astringent enough to be nearly inedible raw and are traditionally picked after the first frost for gin. The Irish shillelagh is cut from blackthorn root and stem.