a. Proximal portion of flowering stem. b. Distal portion of flowering stem. c. Node with interpetiolar stipules (hairs removed from around stipules). d. Leaf surfaces enlarged, adaxial (left) and abaxial (right). e. Umbel of flower buds. f. Flower, posterior petal uppermost. g. Flower with petals removed, side view, anterior sepal to left. h. Anthers, adaxial view (left) and abaxial view (right). i. Apex of style. j. Adaxial view of samara stilll attached to receptacle by carpophore. k. Abaxial view of samara. l. Flower after fall of samaras. Scale bar equivalents:
a, b, 4 cm; c, d, 4 mm; e, 8 mm; f, 1 cm; g, 4 mm; h, i, 2 mm; j, k, 1.3 cm; l, 5 mm. Based on: a, b, d–i, Anderson & Anderson 5104, MICH; c, Wilbur & Wilbur 2306, MICH; j–l, Feddema 1416, MICH. Drawn by Karin Douthit. © University of Michigan Herbarium.