Shrubs or trees, crown rounded. Stems smooth; young twigs reddish brown, bark longitudinally fissured. Winter bud scales 1, enclosed by petiole wings, compressed, 2-5 mm, silvery-pubescent. Leaves: petiole 2-15 mm, wing 1-2 mm wide; blade ovate to widely elliptic, (3-)8-12(-15) × (2-)4-7(-8.5) cm, base broadly cuneate to rounded, margins serrulate to erose, ciliate, apex acute to acuminate, abaxial surface sparsely pubescent, primary veins in 5-7 pairs. Inflorescence bracts 1, 10-15 mm. Pedicels 0.3-0.4(-0.7) cm × 1 mm. Flowers (5-)6-10 cm diam.; sepals lanceolate, (11-)14-18 × 6-9 mm; petals 5(-8), creamy white, margins erose, abaxial surface pubescent; stamens 100-125(-150); filaments white, yellow, rose, or purple, free portion 12-18(-20) mm; anthers yellow; styles 5; stigmas unlobed. Capsules ovoid, 1.5-2.2 × 1.4-1.6 cm, apex acute, pubescent. Seeds reddish brown, winged, planoconvex, (7-)8-10 × 5-7 mm, dull, wing 0.1-1 mm wide. 2n = 30. Flowering (May-)Jun-Jul(-Oct). Shaded, moist ravines and gorges; (100-)200-1100 m; Ala., Ga., Ky., Miss., N.C., S.C., Tenn., Va. Stewartia ovata is likely not naturally occurring in Florida; the only specimen seen is from cultivation in an Alachua County nursery (Wilmot s.n., 21 May 1945, FLAS). Human threats to the species include land-use conversion and habitat fragmentation. A form with purplish filaments [var. grandiflora (Bean) Weatherby] is generally not recognized and is hypothesized to be the result of either genetic instability (C. E. Wood Jr. 1959b) or introgression with S. malacodendron. Stewartia ovata is cultivated as an ornamental for its showy flowers and red fall foliage.
Shrub to 5 m, lvs elliptic to oblong-ovate, 6-15 cm, distinctly acuminate, obscurely to conspicuously serrulate, broadly acute to rounded below, hairy beneath; fls subsessile, 7-10 cm wide; filaments purple or white; styles 5; fr ovoid, 2 cm, sharply 5-angled, pointed, villous; seeds dark, dull, flattish, thin-edged or (especially at one end) narrowly winged; 2n=30. Mt. woods; e. Ky. to n. Va. and n. Ala. June. (S. pentagyna; Malachodendron p.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.