Previously included in Cassia and still often sold as such, these species have been reclassified as Senna—a move not accepted by all botanists. Grown for their lavish show of bright yellow, five-petaled flowers that look something like those of potentilla. Blossoms are followed by seedpods that may create litter; to reduce pod production, prune lightly after flowering. Rangy, rank growers should also be cut back periodically to encourage more compact growth. Good for screens, massing, and background plantings. Prefer well-drained soil.Senna artemisioides
Evergreen shrub, native to Australia. Grows to 3–5 ft. tall and wide, with attractive, light, airy structure. Gray leaves are divided into six to eight needle-like, 1-in.-long leaflets. Bears 3/4-in. bright yellow flowers in clusters of five to eight in winter and spring, with bloom often continuing into summer. In the desert, plants may rest in summer, then resume flowering in fall. Heavy seed production. Very drought-tolerant but looks better with moderate to regular water.
Native from Texas to Argentina, where these bulbous perennials sprout and flower almost immediately af...
Evergreen to deciduous South American shrub or tree; drops leaves in cold winters. Zones 8–16, 1...
Himalayan native useful as a screen or background plant. Grows slowly at first, then moderately fast t...