Sequoia gigantea vs Sequoiadendron giganteum

Sequoia gigantea and Sequoiadendron giganteum both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sequoia gigantea	Yes	No	No	No
Sequoiadendron giganteum	Yes	No	No	No

As nouns, Sequoia gigantea and Sequoiadendron giganteum are synonyms defined as:

Sequoia gigantea and Sequoiadendron giganteum: extremely lofty evergreen of southern end of western foothills of Sierra Nevada in California; largest living organism

Other synonyms of Sequoia gigantea include big tree, giant sequoia, Sequoia Wellingtonia, Sierra redwood.

Sequoia gigantea (noun)	Sequoiadendron giganteum (noun)
extremely lofty evergreen of southern end of western foothills of Sierra Nevada in California; largest living organism	extremely lofty evergreen of southern end of western foothills of Sierra Nevada in California; largest living organism