Specimen record
American Elm
Ulmus americana
Conservation note
Populations reduced by Dutch elm disease (Ophiostoma novo-ulmi). Surviving trees may be resistant — note the tree's health on the label.
Description
Once the quintessential street tree of American towns, American elm was devastated by Dutch elm disease in the mid-20th century. Surviving specimens and young trees can still be found along roadsides and near streams. The tree is recognized by its classic vase-shaped crown, with branches arching gracefully outward and upward. It flowers inconspicuously in early April before the leaves emerge.
Identification tips
- 1Classic vase-shaped crown on mature trees (branches arch outward and upward)
- 2Leaves alternate, doubly serrate, with an asymmetric (lopsided) base
- 3Papery, flat, oval samaras with a notched tip, ripening in May
- 4Bark with deep, interlacing ridges in a diamond pattern on mature trunks
- 5Tiny reddish-purple flowers in clusters along twigs in early April (before leaves)
Specimen & preservation notes
Collect spring flowering twigs before leaves emerge. Press leaves showing the diagnostic asymmetric base clearly. Include the papery samaras — they press perfectly flat. Photograph the vase-shaped crown from a distance for the herbarium sheet.
Habitats
Collection calendar
| Wk | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov |
|---|---|---|---|---|---|---|---|---|
| 1 | ||||||||
| 2 | ||||||||
| 3 | ||||||||
| 4 |
Collection notes
Season check
Observed bloom also extends into March.
Flowering records: 12 iNaturalist observations, Massachusetts · Nearby: 532 observations within 25 km