Leaves undersurface white and densely hairy. Flower clusters to about 40 cm long. Stamens about 20-30; summer. Fruit a capsule with 4-6 seeds.

China, Japan

M. microcarpa (Maxim.) Fedde, the other species in the genus, is occasionally offered in nurseries; it differs primarily in having 8-12 stamens and a more or less round, not slightly elongated, 1-seeded capsule.

Suckers (the root system is highly invasive).

Yellow sap; leaves with many lobes; flowers small, whitish and in large clusters; capsule with 4-6 seeds.

Source: Spencer, R. (1997). Papaveraceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.