Stems prostrate to weakly ascending, forming loose mats, hairy. Leaves not or somewhat imbricate, closely appressed to stem, not strongly 4-ranked; blade linear-lanceolate, abaxial groove absent, 2–3 × 0.5–1.2 mm, margins conspicuously scarious, curled hairs present at leaf tips (at least on young leaves), abaxial base and adaxial surface hairy. Flowers: sepals 1.5–2 mm, margins hyaline; petals connate for ca. 1/2 their lengths, tips recurved, corolla white, campanulate, 6–8 mm; stamens to 3 mm. Capsules ca. 3 mm.
Subshrubs, shrubs, or trees, multicellular hairs present; bark smooth or furrowed, not flaky (peeling or shredding in Menziesia). Stems erect to decumbent, sprawling, creeping, trailing, prostrate, or procumbent. Leaves deciduous or persistent, usually alternate, sometimes opposite, whorled, or spirally arranged; petiole usually present; blade plane or acicular, abaxial groove present or absent. Inflorescences axillary or terminal, fascicles, racemes, panicles, capitula, cymes, umbels, corymbs, spikes, or solitary flowers; perulae present or absent; bracts much shorter than sepals (sometimes absent). Flowers bisexual or unisexual, erect or pendulous, usually radially or bilaterally symmetric; sepals (2–)4–5(–7); petals absent or (2–)4–5(–7), connate or distinct, corolla deciduous or persistent, campanulate, salverform, rotate, saucer-shaped, funnelform, cylindric, or urceolate, (with pockets holding anthers until they open in some Kalmia), lobes shorter than tube; intrastaminal nectary disc present; stamens (2–)5–10; anthers dehiscent by lateral pores or slits; ovary (2–)5–10-locular; placentation axile (parietal distally in Epigaea); style straight or declinate (curved in Elliottia). Fruits capsular, dehiscence usually septicidal, sometimes loculicidal or septifragal, or drupaceous, (dry to fleshy), indehiscent. Seeds 2–300, distinct, obovoid, ovoid, or ellipsoid to oblong, linear, fusiform, or planoconvex, winged or not.
