Lowland dry forest in which the endemic Metrosideros polymorpha (Myrtaceae) is usually present, but only predominating on Hawai’i, occurs on all of the main islands up to an altitude of about 1500 m. However, they tend to be confined to the dryer rain shadow areas. The canopy height varies from 4 to 20 m, and apart from the summer deciduous endemic species Erythrina sandwichensis (Fabaceae), Euphorbia haeleeleana (Euphorbiaceae) and Reynoldsia sandwicensis (Araliaceae) all of the woody plants are evergreen. The diversity of these forests seem to be correlated with island age with the best examples on the geologically older Kaua’I and O’ahu, while the examples on Hawai’i are relatively impoverished. Other important canopy trees include the endemic Colubrina oppositifolia (Rhamnaceae), Diospyros sandwicensis (Ebenaceae) and Nestegis sandwicensis (Oleaceae), any one of which may dominate depending on the area. Today only a few relict stands remain of this once extensive forest system, and in these can be found many other endemic trees such as Alphitonia ponderosa (Rhamnaceae), Antidesma pulvinatum (Euphorbiaceae), Bobea sandwicensis (Rubiaceae), Charpentiera obovata (Amaranthaceae), Gardenia brighamii (Rubiaceae), Kokia drynarioides (Malvaceae), Myrsine lanaiensis (Myrsinaceae), Nothocestrum brevifolium (Solanaceae), Pittosporum hosmeri (Pittosporaceae), Pleomele aurea (Agavaceae), Pouteria sandwicensis (Sapindaceae), Rauvalvia sandwicense (Apocynaceae), Santalum ellipticum (Santalaceae), Sapindus oahuensis (Sapindaceae), Xylosma hawaiiense (Flacourtiaceae) and Zanthoxylum dipetalum (Rutaceae). In some cases these forests are somewhat open with a grassy ground layer, but where there is a closed canopy a diverse assemblage of under storey species can be found including many endemic shrubs like Delissea rhytidosperma (Campanulaceae) and Gossypium tomentosum (Malvaceae). Epiphytes, on the other hand, are scare, but there are a few endemic lianas such as Alyxia oliviformis (Apocynaceae) and Bonamia menziesii (Convolvulaceae). 

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