a. Flowering branch. b. Petiole and base of lamina. c. Base of petiole to show epipetiolar stipule. d. Flower. e. Petal, adaxial view. f. Abaxial view of young anther (above) and twisted old anther (below). g. Distal portion of style with apical stigma. h. Samara, adaxial view. i. Nut of samara with lateral wings cut away, lateral view to show dorsal wing. j. Samara, abaxial view. Scale bar equivalents:
a, 4 cm; b, 1.3 cm; c–e, 4 mm; f, 2 mm; g, 0.7 mm; h–j, 1.3 cm. Based on: a–g, Breedlove 50224, CAS; h–j, Nelson 2563, NY. Drawn by Karin Douthit. First published in Contr. Univ. Michigan Herb. 25: 123. 2007; reproduced with permission of the authors.