Ironwood is a common name for a large number of woods or plants that have a reputation for hardness, or specifically a wood density that is over 1000 kg/m3 and sinks in water. Usage of the name ironwood in English may (or may not) include the tree that yields this heavy wood.
The equivalent German language term "Eisenholz” is given only to woods of plants with their wood weight of nearly 1000 kg/m3 or more, see German Wikipedia: Eisenholz
Acacia estrophiolata
Acacia stenophylla flowers
Carpinus caroliniana leaves
Casuarina equisetifolia subsp. incana
Chionanthus foveolatus leaves
Eusideroxylon zwageri leaves
Holodiscus discolor flowers
Libidibia ferrea
Lyonothamnus floribundus
Mesua ferrea
Nestegis apetala
Olea capensis
Olea woodiana
or may refer to