Gen. N. Amer. Pl.2: 233. 1818, name conserved
Common names: Osage-orange bois d'arc
Etymology: for American geologist William Maclure, 1763-1840
Found in FNA Volume 3. Treatment on page 393.
Trees, deciduous; sap milky. Branches with axillary spines. Terminal buds surrounded by bud scales. Leaves alternate; stipules caducous, free. Leaf blade ovate to lanceolate, not leathery, margins entire, never lobed; venation pinnate. Inflorescences: flowers borne outside receptacle; staminate inflorescences loose short racemes; pistillate inflorescences dense heads. Flowers: staminate and pistillate on different plants. Staminate flowers: calyx 4-lobed; stamens 4, inflexed; filaments filiform; anthers introrse, with short connective. Pistillate flowers: sepals 4, 2 outer sepals wider than inner ones; ovary 1, superior, 1-locular; style unbranched, filiform. Syncarps globose, 8-12 cm or more diam.; each achene completely enclosed by its enlarged, fleshy calyx.
Species 1 (1 in the flora).
Maclura is a monotypic genus endemic to North America.