The Cashew or Sumach family is mainly tropical comprising about 50 genera with 500 species of trees, shrubs and woody vines. Its members are not valuable as wood producers but in many cases they have commercial importance on account of their acrid, milky, or resinous juice, used in medicine, tanning, and the manufacture of varnishes and resins, and on account of their attractive appearance when planted as ornaments. The genus Rhus, (pp. 169, 171, 173) is the only one native to Northeastern America. There are 120 known species of Rhus, about 16 of which are found in North America and 6 in West Virginia. Besides those described in this bulletin the following shrubby species grow wild in the State: Smooth Sumach (Rhus glabra, L.), Poison Ivy (Rhus Toxicodendron, L.) and Fragrant Sumach (Rhus canadensis, Marsh.)

The Smoke Tree (Rhus Cotinus, L.), an introduced tree, is planted on lawns.