Plants stoloniferous. Flowering stems erect, 5-45 cm. Leaves: blade 1-12 cm wide, 1-2 times toothed, 7-11-lobed for 1/3-1/2 length, lobes cuneate to cuneate-oblong; margins entire or erose with long bristles. Inflorescences erect, primary and higher-order branches perpendicular to central axis. Flowers: hypanthium widely turbinate-campanulate, portion distal to adnation to ovary marked by conspicuous flaring, 1.5-2.5 × 2-4.5 mm, stipitate-glandular proximally; sepals triangular, 0.9-1.5 × 0.8-1.2 mm, broader than long at apex, apex acute; petals unlobed, 1.6-2.5 mm, suborbiculate, abruptly clawed, 1-1.8 mm wide; ovary 4/5+ inferior. Capsules cylindric, 3.8-7.1 × 1.2-2.6 mm, beaks ± spreading. Seeds dark red-brown, 1.1-1.7 × 0.3-0.5 mm, main body (excluding winged margins) 0.8-1 mm. 2n = 14. Flowering May-Jul. Moist, basaltic cliffs, typically near waterfalls; 0-400(-1400) m; Oreg., Wash.