a. Flowering branch, and abaxial view of detached large leaf. b. Node with interpetiolar ridge bearing stipules. c. Apex of petiole, adaxial view, to show large glands. d. Flower bud. e. Flower, posterior petal to right. f. Androecium and gynoecium, view from behind with short stamen opposite posterior petal in foreground. g. Androecium and gynoecium, lateral view, posterior petal to left. h. Gynoecium. i. Enlarging fruits enclosed by accrescent sepals. j. Immature fruit. k. Samara. Scale bar equivalents:
a, 4 cm; b, c, 4 mm; d, 8 mm; e, 1.3 cm; f–h, 4 mm; i, 4 cm; j, 1.3 cm; k, 2 cm. Based on: a–j, Anderson et al. 36981, MICH; k, Harley 21676, MICH. Drawn by Karin Douthit. Modified from a drawing first published by W. R. Anderson in Contr. Univ. Michigan Herb. 11: 52. 1975.