ironwood tree vs iron tree

ironwood tree and iron tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
ironwood tree	Yes	No	No	No
iron tree	Yes	No	No	No

As nouns, ironwood tree and iron tree are synonyms defined as:

ironwood tree and iron tree: a small slow-growing deciduous tree of northern Iran having a low domed shape

Other synonyms of ironwood tree include iron-tree, ironwood.

ironwood tree (noun)	iron tree (noun)
a small slow-growing deciduous tree of northern Iran having a low domed shape	a small slow-growing deciduous tree of northern Iran having a low domed shape
medium-sized hop hornbeam of eastern North America
handsome East Indian evergreen tree often planted as an ornamental for its fragrant white flowers that yield a perfume; source of very heavy hardwood used for railroad ties