Brooklyn Botanic Garden

Ulmus americana


by Science Staff
Not peer reviewed
Last modified: 03/19/2013


Ulmus L., Sp. Pl. 225. 1753. Gen. Pl., ed. 5, 106. 1754. LECTOTYPE: Ulmus campestris L., designated by Britton & Brown (1913).

Microptelea Spach, Ann. Sci. Nat. Bot. ser. 2. 15: 358. 1841. TYPE: Microptelea parvifolia (Jacq.) Spach (=Ulmus parvifolia Jacq.).

Key to the species of Ulmus

1. Leaf blades less than 7 cm...Ulmus pumila
1. Leaf blades greater than 7 cm...2

2. Upper surfaces of leaves rough, sandpapery...4
2. Upper surfaces of leaves smooth...3

3. Samaras pubescent on the sides; inflorescences racemes; older branches with cork-ridges...Ulmus thomasii
3. Samaras glabrous on the sides; inflorescences fascicles; older branches without cork-ridges...Ulmus americana

4. Older twigs with corky wings...Ulmus minor (U. procera)
4. Older twigs lacking corky wings...5

5. Leaves ciliate; buds covered with rusty hairs; fruit pubescent...Ulmus rubra
5. Leaves not ciliate; buds pale-pubescent or glabrous; fruit glabrous...6

6. Young branches pubescent; fruit with the seed in the middle...Ulmus glabra
6. Young branches glabrous; fruit with the seed above the middle (commonly cultivated)...Ulmus ×hollandica

List of Ulmus Species


References to Ulmus

Back to Ulmaceae Page

Brooklyn Botanic Garden