Pteropogon humboltianum vs pteropogon

Pteropogon humboltianum and pteropogon both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pteropogon humboltianum	Yes	No	No	No
pteropogon	Yes	No	No	No

As nouns, Pteropogon humboltianum and pteropogon are synonyms defined as:

Pteropogon humboltianum and pteropogon: southern Australian plant having feathery hairs surrounding the fruit

Pteropogon humboltianum (noun)	pteropogon (noun)
southern Australian plant having feathery hairs surrounding the fruit	southern Australian plant having feathery hairs surrounding the fruit