Description
Key Characters:
Growth Form:
Shrubs, 5–30 dm.
Stems:
Stems branched, tomentose.
Roots:
Leaves:
Leaves simple.
Opposite.
Blades ovate to ovate–lanceolate, 10–15 × 2–4 cm.
Apex acute or acuminate.
Base attenuate or cuneate.
Upper surfaces glabrous or glabrescent; lower surfaces tomentose.
Margins serrate or subentire.
Petioles 5 mm long.
Stipules present, auriculate.
Flowers:
Flowers in inflorescences terminal, tapered–spicate or narrowly paniculate thyrses, 10–20 × 2–4 cm, cymes almost encircling inflorescence axis, 10–25 pairs, 3–30–flowered. pedicels essentially absent; bracteoles present.
Flowers bisexual (perfect) fragrant.
Calyx sparsely hairy externally, tube 1.5–2 mm, lobes 0.5–1.5 mm.
Corolla straight, violet or pink, rarely white, often with yellow–orange eye, salverform, tube 8–10 mm, lobes suborbiculate, 2–3 × 2–3 mm.
Stamens 4, adnate to corolla tube, included, rarely exserted, equal; filaments glabrous, staminode 0.
Ovary superior, ovoid, 2 mm, glabrous or puberulent; stigma clavate, 1 mm.
Fruit:
Capsules brown; narrowly ellipsoid; 5–9 × 1.5–2 mm; glabrous or puberulent; dehiscence primarily septicidal.
Seeds threadlike; 3–4 × 0.5 mm; wings long.
Ploidy:
2n = 76
Habitat:
Roadsides; railroad embankments; quarries; streambeds; landslide scars; sandy lakeshores; disturbed sites.
Elevation Range:
0–1,300 m.