a. Flowering branch, with enlargement of abaxial leaf surface to show glands. b. Node with stipules. c. Flower bud. d. Flower, posterior petal uppermost. e. Flower with lateral petals removed, base of posterior petal to left. f. Androecium laid out, adaxial view, with stamen opposite posterior petal at far right, the two reduced anthers hidden by larger neighbors. g. Reduced stamen from opposite posterior-lateral petal. h. Gynoecium, side view, anterior style to left. i. Distal portion of styles, anterior (left) and posterior two (right). j. Fruit with two samaras developed. k. Samara with a small third wing. l. Embryo. Scale bar equivalents:
a, 4 cm (4 mm); b, 4 mm; c, 8 mm; d, 1 cm; e, 4 mm; f, 3.3 mm; g, 1.3 mm; h, 2.7 mm; i, 1.3 mm; j, k, 4 cm; l, 8 mm.—Based on Soejarto et al. 4416, MICH. Drawn by Karin Douthit. First published in Contr. Univ. Michigan Herb. 14: 12. 1980; reproduced with permission of the author.