Lagerstroemia vs plant genus

Lagerstroemia and plant genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lagerstroemia	Yes	No	No	No
plant genus	Yes	No	No	No

As nouns, plant genus is a hypernym of Lagerstroemia; that is, plant genus is a word with a broader meaning than Lagerstroemia:

Lagerstroemia: shrubs or small trees of tropical Asia and Africa usually with showy white, pink, or purplish flowers
plant genus: a genus of plants

Lagerstroemia (noun)	plant genus (noun)
shrubs or small trees of tropical Asia and Africa usually with showy white, pink, or purplish flowers	a genus of plants