a. Flowering branch. b. Abaxial surface of lamina. c. Base of leaf, abaxial view, and node with interpetiolar stipules. d. Umbel of flower buds. e. Flower, posterior petal uppermost. f. Flower, lateral view with sepals cut away and petals removed except claw of posterior petal to right. g. Same as f, but with two lateral stamens in foreground removed to show style. h. Anther, abaxial view. i. Apex of style. j. Immature fruit with sepals cut away (left) and detached anterior samara (right). Scale bar equivalents:
a, 4 cm; b, 3.3 mm; c, 1.3 cm; d, 8 mm; e, 1.3 cm; f, g, 8 mm; h, i, 2 mm; j, 8 mm. Based on: a–d, j, Prance 13770, MICH; e–i, Anderson 12334, MICH. Drawn by Karin Douthit. First published by W. R. Anderson in Contr. Univ. Michigan Herb. 16: 88. 1987.