This is a fine hardy plant about 4 ft. high, with dense feathery masses of white Ageratum-like flowers in August and September. It grows freely in any soil, and may be increased by division or seeds.

The following species are best grown in a greenhouse, and may be propagated from cuttings inserted in sandy soil in spring: atrorubens, reddish purple; probum, white; riparium, white, red stems; trapezoideum (or adenophorum), white, tall-growing.