Edinburgh New Philos. J. 17: 159. 1834,.
Shrubs, to 1.5 m. Stems erect, terete to slightly angled. Leaves deciduous; blade narrowly to widely elliptic, ovate, or obovate, (2.5–) 3–8 (–10.5) × 1–4 (–5) cm, membranous, base narrowly cuneate to rounded, margins entire, plane to slightly revolute, apex acute to rounded-mucronate or slightly acuminate, surfaces scattered, multicellular, glandular short-headed-hairy, not lepidote, otherwise glabrous or hairy on major veins, intramarginal vein absent. Inflorescences fascicles, developing from buds along distal portion of stems of previous year; bracts 1 per flower, linear-lanceolate, to 4.5 mm. Pedicels glandular-hairy, not lepidote. Flowers: calyx lobes 3–9.5 × 1–4 mm, glandular-hairy, not lepidote; corolla usually white, rarely pink, cylindric (base not swollen), 7–14 × 4.5–9 mm; filaments 4–7 mm, long-hairy, especially near base, with 2 ± well-developed spurs. Capsules ovoid, 4–6.5 × 3–6 mm, apex strongly constricted, short-headed-hairy, otherwise glabrous or hairy; sutures usually remaining attached to adjacent valve; placentae central to nearly basal. 2n = 24.
Phenology: Flowering spring.
Habitat: Open, acid, dry to moist pine and/or oak forests, flatwoods, or savannas, often in ecotonal situations, less often in shrub bogs, pond margins, and acid swamps
Elevation: 0-200 m
Ark., Conn., Del., Fla., Ga., La., Md., Miss., Mo., N.J., N.Y., N.C., Okla., Pa., R.I., S.C., Tex., Va.
Leaves of Lyonia mariana (and probably other species as well) contain andromedotoxin and are known to cause livestock poisoning; the species is occasionally used as an ornamental. The western populations tend to be much hairier than those of the Atlantic coastal plain.
"entire" is not a number.