iron tree vs iron-tree

iron tree and iron-tree both are nouns.

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

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

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

Other synonyms of iron tree include ironwood, ironwood tree.

iron 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