red buckeye vs buckeye

red buckeye and buckeye both are nouns.

Word	Noun	Adjective	Verb	Adverb
red buckeye	Yes	No	No	No
buckeye	Yes	No	No	No

As nouns, buckeye is a hypernym of red buckeye; that is, buckeye is a word with a broader meaning than red buckeye:

red buckeye: a shrub buckeye of southern United States
buckeye: tree having palmate leaves and large clusters of white to red flowers followed by brown shiny inedible seeds

Other hypernyms of red buckeye include Aesculus hippocastanum, horse chestnut.

red buckeye (noun)	buckeye (noun)
a shrub buckeye of southern United States	tree having palmate leaves and large clusters of white to red flowers followed by brown shiny inedible seeds
	the inedible nutlike seed of the horse chestnut