The 152 species described and illustrated by line drawings comprise 60 native species (including 53 that are endemic), 85 species introduced after the arrival of Europeans, and 7 species introduced apparently by the early Hawaiians. The native tree species of Hawaii are mostly scattered in distribution and of small size. Only two native tree species presently are commercially important for wood, because of their abundance and large size: 'ohi'a lehua, Metrosideros polymorpha, and koa, Acacia koa. Of the two, only koa is considered to be of high value.
The introduced species described include 13 species of eucalypts (Eucalyptus), 5 species of pines (Pinus), and 11 other conifers. Two plant families are well represented, the myrtle family (Myrtaceae), with 25 species, and the legume family (Leguminosae), with 15. One chapter is devoted to forests and forestry in Hawaii. Maps of the Hawaiian Islands show the physical features and place names, major forest types, and forest reserves and conservation districts.