Description: Forms a large clump of deeply toothed, heart-shaped foliage topped in early- to mid-summer by long racemes of bright yellow flowers.
Origin: Japan and Northern China.
Height x width: 6 feet tall and about 3 feet wide.
Growth habit: Upright clumps. Flower stems are 1.5 to 2 feet tall.
Foliage: Basal leaves have petioles that circle the stem with a short sheath. The plant also produces alternate leaves on stems. Leaves are heart-shaped or triangular, toothed and up to 1 foot long.
Flowers: Lemon yellow flowers on dark-purple-stemmed racemes 4 to 6 feet tall.
Culture: Filtered shade and moist soil. The long racemes grow vertical in full sun but the leaves wilt in midday even with adequate soil moisture. The wilted leaves will recover at night. Prefers cooler temperatures, especially at night.