7. Euonymus Linnaeus, Sp. Pl. 1: 197. 1753 (as Evonymus); Gen. Pl. ed. 5, 91. 1754. name and orthography conserved.
[Greek eu-, good, and onyma, name, apparently applied ironically, the genus having had the bad reputation of poisoning cattle] [Greek eu-, good, and onyma, name, apparently applied ironically, the genus having had the bad reputation of poisoning cattle]
Geoffrey A. Levin
Shrubs, trees, or vines, <climbing by adventitious roots>. Branchlets terete or 4-angled. Leaves deciduous or persistent, opposite; stipules present; petiole present; blade margins entire or toothed; venation pinnate. Inflorescences terminal or axillary, cymes. Flowers bisexual, radially symmetric; perianth and androecium hypogynous; hypanthium absent; sepals 4–5, distinct; petals 4–5, white, green, yellow, red, or purple; nectary intrastaminal, annular, fleshy; stamens 4–5, adnate to nectary margin; staminodes 0; pistil 4–5-carpellate; ovary superior, 4–5-locular, placentation axile; style 1; stigma 1; ovules 2 per locule. Fruits capsules, (1–)2–5-locular, globose, subglobose, or obovoid, unlobed or 2–5-lobed, apex not beaked. Seeds 2 per locule, ellipsoid, ovoid, or subglobose, not winged; aril yellow, orange, or red, completely surrounding seed. x = 16.
Species ca. 140 (7 in the flora): North America, Mexico, West Indies, Central America, Europe, e, se Asia, Africa; tropics and subtropics.
Several cultivated species of Euonymus, all native to eastern Asia, are established locally in the flora area and, although apparently not naturalized, should be watched for invasive tendencies. Two of these, E. hamiltonianus Wallich, reported from Illinois, Indiana, and Michigan, and E. maackii Ruprecht (= E. bungeanus Maximowicz), reported from Colorado, Florida, Georgia, Illinois, and South Carolina, are similar to each other and to E. europaeus, from which they both differ by having purple (versus white) anthers. In addition, E. hamiltonianus can be distinguished by its red (versus orange or yellow) arils, and E. maackii by its leaf blades with smooth (versus rough) surfaces. Euonymus japonicus Thunberg, reported from Indiana, Louisiana, Mississippi, North Carolina, and Virginia, is similar to E. fortunei but is a shrub with erect stems that never produce adventitious roots. Euonymus phellomanus Loesener, reported from Connecticut and Massachusetts, has corky winged branches like E. alatus, but has larger leaves (6–10 × 2–3 cm) and yellow-brown to red-brown, four-angled capsules.
SELECTED REFERENCES Blakelock, R. A. 1951. A synopsis of the genus Euonymus L. Kew Bull. 6: 210–290. Ma, J. S. 2001. A revision of Euonymus (Celastraceae). Thaiszia 11: 1–264.