Samples of pineland threeawn, Curtiss drop-seed, bluestem grasses, other grasses, forbs, and shrubs were collected at 2-week intervals during the grazing season (April to October) on pine-wiregrass range in southern Georgia. They were analyzed for nylon bag dry-matter digestibility (NBDMD), two-state in vitro dry-matter digestibility (IVDMD) by cattle, crude protein (CP), cell-wall constituents (CWC), and dry matter (DM). NBDMD and IVDMD were highly correlated for each species or group of species and for all species together, indicating that both methods gave a similar estimate of digestibility for herbaceous plants. The shrub sample, which contained woody twigs along with leaves, was more digestible in NBDMD and IVDMD tests; however, the correlation between the two techniques was high. As the season advanced through late summer, CP and IVDMD decreased and DM increased. The poor quality of forage on pine-wiregrass range was indicated by CP levels under 8% and IVDMD of less than 40% during most of the grazing season. Crude protein appeared useful for predicting digestibility of grasses but not forbs and shrubs. Neither CWC nor DM appeared useful for predicting digestibility of forbs and shrubs.