yellowwood, common name for any species of the genus Cladrastis, leguminous trees of the family Leguminosae (pulse family). Three of the four species are native to China and Japan. The other, C. lutea, is native to the SE United States and is cultivated as far north as Massachusetts, chiefly as an ornamental for the bright green leaves and the fragrant white blossoms. A dye has been obtained from the yellow heartwood. The name yellowwood is used also for several unrelated trees yielding yellow lumber, e.g., Podocarpus thunbergii and P. elongata, conifers of S Africa used in construction; Schaefferia frutescens of S Florida and the West Indies, sometimes also called boxwood and used in engraving as a substitute for true boxwood; and West Indian satinwood. Cladrastis is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Leguminosae.