Live oak leaves and soil samples were collected from 16 sites from south Georgia and northcentral Florida. The sclerophyll index (crude fiber x 100/crude protein) varied from 204 to 507. Much of the site to site variation (r2 = 0.60) could be accounted for by the combined effects of soil Ca and P levels. The sclerophyll index of 16 deciduous and 9 evergreen species from the southeast are compared. The deciduous species are less sclerophyllous than the evergreen species and they have higher levels of leaf N and P.