1. Inflorescence is a terminal upright panicle. The flowers are bisexual; the upper ones functionally male, those below protogynous. - 2. The leafs are compound, consisting of 5 to 7 leaflets of which the medial is the largest. - 3. Ripe, three-valved leathery, prickly capsules: one is closed (a) the another one is just opening (b). - 4. Ripe seed (conker) in dorsal (c) and basal (d) sides, the latter with large, light-colored hilum. - 5. Winter-branchlet; buds are large, the terminal ones the largest, viscid, resinous, reddish-brown to nearly black. Leaf-scars are large, shield-shaped or irregular. After Hempel & Wilhelm, 1889. Photos and explanations from the book: Zelimir Borzan. "Tree and Shrub Names in Latin, Croatian, English, and German, with synonyms", University of Zagreb, 2001.