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.
A small genus of annual herbs with narrow entire leaves. Flowers on long peduncles, yellow. Sepals 3. Petals 6. Stamens numerous, with dilated filaments. Carpels numerous, many-seeded, at first partially united, but free when mature. The name is from broad, and a stamen. Two species have been described; they are both dwarf hardy plants of straggling habit and no great merit.
1. P. Californicus. - Leaves and capsules hairy. Native of California, flowering in August.
2. P. leiocarpus. - Capsules smooth, flowers yellowish white. A native of Siberia.