BERBERIDACEAE (Barberry Family)

Contributed by Alan Whittemore

Shrubs or rhizomatous perennial herbs, stems sometimes spiny. Leaves basal, alternate, or subopposite, simple or compound. Flowers actinomorphic, perfect, hypogynous; sometimes with 3–4 bractlets adjacent to the calyx. Calyces of 6 free sepals, sometimes falling as flowers open. Corollas of 6–9 free petals, these showy or inconspicuous. Stamens 6–18, free, the anthers opening by apical flaps or longitudinal slits. Pistil 1 per flower, of apparently 1 carpel. Ovary superior, with 1 locule, the placentation basal. Style short or absent, the stigma appearing sessile. Fruits berries or capsules, or the fruit wall rupturing early in development and the seeds then exposed at maturity. Seeds 1–50 per fruit. Fifteen genera, about 650 species, North America, Europe, Asia, and the mountains of South America and east Africa.

The structure of the pistil in plants of this family is very simple, with a single unlobed stigma and an ovary having a single locule containing basal ovule(s). It is not clear whether the pistil is composed of a single carpel, like the pistils of Ranunculaceae and Menispermaceae, or of several fused carpels, as in Papaveraceae and Fumariaceae.

In addition to the five species included here, there are unconfirmed reports of Jeffersonia diphylla (L.) Pers. (twinleaf) from Missouri. Steyermark (1963) excluded the species from the flora and did not accept an anecdotal report by B. F. Bush of a population in a creek bottom in Taney County. More recently, members of the Webster Groves Nature Study Society have suggested that the species has escaped from plantings at an estate in Jefferson County. Jeffersonia diphylla, which superficially resembles Stylophorum diphyllum (Papaveraceae), is a rhizomatous perennial herb to 30 cm tall with basal leaves having the blades divided into two asymmetrically ovate or kidney-shaped leaflets 7–12 cm long. The solitary, long-stalked flowers open while the leaves are expanding, have white to light pink petals 11–23 mm long, and have stamens with the anthers attached at the base and opening by longitudinal slits. The fruit is a tough-walled, ellipsoidal capsule that opens by the loss of a terminal lid. Twinleaf is known from Illinois and Iowa, and botanists should continue to search for it in Missouri.