Plant: Tree < 12 m, armed with spines at nodes; stem ± zigzag; bark smooth, green Leaves: 1-3 dm, 2-pinnate, alternate; main primary leaflet axis < 30 cm, conspicuous, persistent as ribbon-like streamer; secondary leaflets 30-60, scattered, 3-5 mm, 1-1.5 mm wide, elliptic, ephemeral INFLORESCENCE: raceme, < leaf Flowers: ± 2 cm wide, slightly bilateral; sepals reflexed, ± free, all alike; petals ± round, yellow, banner red-spotted at base, becoming entirely red in age; stamens 10, free, exserted Fruit: legume, dehiscent, 5-10 cm, ± thickened, leathery; Seeds several Misc: Disturbed, dry place; < 400 m. References: Shreve and Wiggins, 1964.J.C. Hickman, ed. The Jepson Manual.