damson plum tree vs bullace

damson plum tree and bullace both are nouns.

Word	Noun	Adjective	Verb	Adverb
damson plum tree	Yes	No	No	No
bullace	Yes	No	No	No

As nouns, bullace is a hypernym of damson plum tree; that is, bullace is a word with a broader meaning than damson plum tree:

damson plum tree: plum tree long cultivated for its edible fruit
bullace: small wild or half-domesticated Eurasian plum bearing small ovoid fruit in clusters

Other hypernyms of damson plum tree include Prunus insititia.

damson plum tree (noun)	bullace (noun)
plum tree long cultivated for its edible fruit	small wild or half-domesticated Eurasian plum bearing small ovoid fruit in clusters