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.
Standard orbicular, slightly exceeding the wings, the sides reflexed; wings oblong-obvate; keel petals as long or longer than the wings, scarcely incurved, connate at the back. Pod stalked and many-seeded; seeds minutely strophiolate. One shrubby species, a native of the Himalayas. From to fall, and
a flower, in allusion to all parts of the flower dropping together.
1. P. Nepalensis. Evergreen Laburnum. - A handsome evergreen shrub requiring a sheltered situation. Leaves alternate, petiolate, digitately trifoliolate; leaflets lanceolate, acute, slightly hairy; stipules united in one, opposite the leaves. Flowers large, yellow, in terminal bracteate racemes.