a. Flowering branch. b. Node with leaflike stipules. c. Node with tiny triangular stipules. d. Abaxial base of lamina and apex of petiole with glands. e. Adaxial surface of lamina. f. Umbel of four flower buds. g. Flower bud. h. Flower. i. Androecium and gynoecium. j. Anthers, adaxial view (left) and abaxial view (right). k. Apex of style. l. Fruit with one samara removed and two samaras separating from torus, still attached by carpophores. Scale bar equivalents:
a, 4 cm; b, e, 5.7 mm; d, e, 4 mm; f, 1.3 cm; g, h, 8 mm; i, 4 mm; j, 2.7 mm; k, 0.4 mm; l, 6.7 mm. Based on: a–h, Brummitt & Pope 19597, MICH; i–k, Goldblatt & Manning 8835, MICH; l, Long & Rae 603, MO. Drawn by Karin Douthit. © University of Michigan Herbarium.