giant reed vs Arundo donax

giant reed and Arundo donax both are nouns.

Word	Noun	Adjective	Verb	Adverb
giant reed	Yes	No	No	No
Arundo donax	Yes	No	No	No

As nouns, giant reed and Arundo donax are synonyms defined as:

giant reed and Arundo donax: large rhizomatous perennial grasses found by riversides and in ditches having jointed stems and large grey-white feathery panicles

giant reed (noun)	Arundo donax (noun)
large rhizomatous perennial grasses found by riversides and in ditches having jointed stems and large grey-white feathery panicles	large rhizomatous perennial grasses found by riversides and in ditches having jointed stems and large grey-white feathery panicles