Grindelia robusta vs gum plant

Grindelia robusta and gum plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
Grindelia robusta	Yes	No	No	No
gum plant	Yes	No	No	No

As nouns, gum plant is a hypernym of Grindelia robusta; that is, gum plant is a word with a broader meaning than Grindelia robusta:

Grindelia robusta: perennial gumweed of California and Baja California
gum plant: any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock

Other hypernyms of Grindelia robusta include gumweed, rosinweed, tarweed.

Grindelia robusta (noun)	gum plant (noun)
perennial gumweed of California and Baja California	any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock