botanist vs phytologist

botanist and phytologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
botanist	Yes	No	No	No
phytologist	Yes	No	No	No

As nouns, botanist and phytologist are synonyms defined as:

botanist and phytologist: a biologist specializing in the study of plants

Other synonyms of botanist include plant scientist.

botanist (noun)	phytologist (noun)
a biologist specializing in the study of plants	a biologist specializing in the study of plants