Iron-wood, in botany: A genus of plants belonging to the class of pentandrae, and to the order of monoecia; and in the natural system ranging under the 4th order, Duma. The corolla is cut into 10 parts, the laciniae or segments being incurved alternately; the stigma is simple; the berry contains five seeds. There are ten species: 1. Mitre; 2. Inermis, smooth iron-wood; 3. Melanophloeum, laurel-leaved iron-wood; 4. Feudiflum; 5. Cynocephalus—both natives of the Cape of Good Hope; 6. Sericeum, silky iron-wood, a native of New South Wales; 7. Tenax, silvery-leaved iron-wood, a native of Carolina; 8. Lycoides, willow-leaved iron-wood, a native of North America; 9. Spinifum, thorny iron-wood or argan, a native of Morocco; 10. Decadrum.

The wood of these trees being very close and solid, has given occasion for this name to be applied to them, it being so heavy as to sink in water. As they are natives of warm countries, they cannot be preserved in this country unless they are placed, the two former in a warm stove, the others in a greenhouse. They are propagated by seeds, when these can be procured from abroad.