Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Rocky stream corridors, forest edge, roadsides, and other disturbed, open areas from low to moderate elevations.
Origin: Introduced from Europe
Conservation Status: Not of concern
Glabrous, rhizomatous, leafy perennial forming large clumps, the several simple stems 4-9 dm. tall.
Leaves opposite, entire, lanceolate to oblanceolate, 4-10 cm. long and 1.5-4 cm. broad, the cauline up to 20 pairs, short-petiolate or the upper sessile.
Flowers fragrant, often double, in a congested inflorescence; calyx tubular, 5-lobed, 15-20 mm. long, 20-nerved, often deeply cleft in 1-2 places; corolla white to pink, the claw equal to the calyx, the blade 10-15 mm. long, obovate, with 2 linear appendages near the base; stamens 10; styles 2.