Decumaria barbata vs hydrangea

Decumaria barbata and hydrangea both are nouns.

Word	Noun	Adjective	Verb	Adverb
Decumaria barbata	Yes	No	No	No
hydrangea	Yes	No	No	No

As nouns, hydrangea is a hypernym of Decumaria barbata; that is, hydrangea is a word with a broader meaning than Decumaria barbata:

Decumaria barbata: woody climber of southeastern United States having white flowers in compound terminal clusters
hydrangea: any of various deciduous or evergreen shrubs of the genus Hydrangea

Decumaria barbata (noun)	hydrangea (noun)
woody climber of southeastern United States having white flowers in compound terminal clusters	any of various deciduous or evergreen shrubs of the genus Hydrangea