Leitneria floridana vs shrub

Leitneria floridana and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Leitneria floridana	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of Leitneria floridana; that is, shrub is a word with a broader meaning than Leitneria floridana:

Leitneria floridana: very small deciduous dioecious tree or shrub of damp habitats in southeastern United States having extremely light wood
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Leitneria floridana include bush.

Leitneria floridana (noun)	shrub (noun)
very small deciduous dioecious tree or shrub of damp habitats in southeastern United States having extremely light wood	a low woody perennial plant usually having several major stems