This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Tall shrubby herbs with yellow or vermilion juice. Leaves large, lobed. Flowers small, numerous, in large terminal panicles. Sepals 2, petaloid. Petals none. Stamens numerous. Capsule stipitate, oblong, few-seeded. Named in honour of a
Sicilian botanist. These plants are grown more for their ornamental habit and foliage than their flowers.
1. B. cordata, syn. Macleaya cordata. - This is the original hardy species, a native of China.
2. B. Japonica. - A handsomer plant than the foregoing. It has large oblong glaucous leaves, deeply lobed and cordate at the base. Both grow from 4 to 6 feet high, and form very striking objects in the garden. Probably a variety of the foregoing. There are two other species, from the West Indies and Mexico.