cuckoo bread vs oxalis

cuckoo bread and oxalis both are nouns.

Word	Noun	Adjective	Verb	Adverb
cuckoo bread	Yes	No	No	No
oxalis	Yes	No	No	No

As nouns, oxalis is a hypernym of cuckoo bread; that is, oxalis is a word with a broader meaning than cuckoo bread:

cuckoo bread: Eurasian plant with heart-shaped trifoliate leaves and white purple-veined flowers
oxalis: any plant or flower of the genus Oxalis

Other hypernyms of cuckoo bread include sorrel, wood sorrel.

cuckoo bread (noun)	oxalis (noun)
Eurasian plant with heart-shaped trifoliate leaves and white purple-veined flowers	any plant or flower of the genus Oxalis