Shrubs, rarely trees. Stems 1–10+. Leaves 3(–5)-foliolate [odd-pinnate]; stipules linear, papery; terminal leaflets long-petiolulate, laterals short-petiolulate or sessile; leaflet blades ovate to elliptic or obovate, base oblique, rounded, or cuneate, lateral ± asymmetric, apex ± acuminate to apiculate, glabrous or sparsely villous, densely when young; hairs unicellular. Thyrses 5–15[–25+]-flowered, on 2d-year wood, pedunculate, bracteate. Pedicels basally 2-bracteolate, with swollen point of disarticulation mid length. Flowers appearing before or with leaves, campanulate or cylindro-campanulate; sepals white or pale greenish pink to pale pink, petaloid, equal to or shorter than petals; petals white [pink]; stamens ± exserted, equal to or longer than petals; pistils short-stalked, stigmas (2–)3(–4)-lobed. Capsules brownish, ellipsoid or obovoid, trigonous, papery; carpels becoming distinct distally; sepals persistent; styles ± persistent. Seeds light brown, ± spheric. x = 13.
North America, Mexico, Eurasia.
Species 10 (2 in the flora).
Staphylea species are cultivated as garden ornamentals.
The two North American species of Staphylea differ in their floral biology: the flowers of S. trifolia are pinkish green (sepals) and campanulate with barely exserted stamens and styles; those of S. bolanderi are white and more tubular (cylindro-campanulate) with well-exserted stamens and styles. These differences appear to correlate with pollinators available in the eastern deciduous forest and in California, respectively.
|1||Leaves abaxially ± villous; flowers campanulate; sepals pale greenish, greenish pink to pale pink to whitish; stamen filaments equal to or slightly longer than petals; filaments (basally) and pistils villous; capsules obovoid; e North America.||Staphylea trifolia|
|1||Leaves glabrous; flowers cylindro-campanulate; sepals white; stamen filaments longer than petals; filaments and pistils glabrous; capsules ellipsoid; California.||Staphylea bolanderi|