white thistle vs quail bush

white thistle and quail bush both are nouns.

Word	Noun	Adjective	Verb	Adverb
white thistle	Yes	No	No	No
quail bush	Yes	No	No	No

As nouns, white thistle and quail bush are synonyms defined as:

white thistle and quail bush: spiny shrub with silvery-scurfy foliage of alkaline plains of southwestern United States and Mexico

Other synonyms of white thistle include Atriplex lentiformis, quail brush.

white thistle (noun)	quail bush (noun)
spiny shrub with silvery-scurfy foliage of alkaline plains of southwestern United States and Mexico	spiny shrub with silvery-scurfy foliage of alkaline plains of southwestern United States and Mexico
any plant of the genus Argemone having large white or yellow flowers and prickly leaves and stems and pods; chiefly of tropical America