Ulmus americana
White elm
5
Nom français: Orme d'Amérique
5
LEAVES – Alternate, simple, doubly toothed. Base is slightly asymmetrical. Upper side of the leaf is somewhat rough. Side veins parallels.
TWIG – Slender with a solid pit. No terminal bud. Axillary buds (the ones on the side of the twig) are pointy and brown, the scales are slightly hairy.
BARK – Reddish-brown on young trees, with shallow fissures. Becoming dark gray and flaky. Has layers of white and brown when a thick piece is broken across.
FRUITS – Produced early summer. The fruit is called a samara, like the fruits of the maples and the ashes. However, the elm samaras have a flat seed surrounded by a thin papery wing. The white elm samara usually have hair only at the edge of the papery wings and a notch at the tip.
Tall tree reaching 40 meters high. Its elegant vase like silhouette is very characteristic and can easily be spotted in open fields. It grows well in rich and humid soils, thriving in the great St-Lawrence clay plain. It used to be one of the most common trees of the Canadian countryside and cities but, victim of the Dutch elm disease, matures trees are now quite rare. The disease is caused by a fungi transported by a bark beetle. It would have been introduced to North-America in the 20s through a shipment of log coming from the Netherlands.
Fontes e Créditos
- François André Michaux (book author), Augustus Lucas Hillhouse (translator), Bessa (illustrator), Gabriel (engraver), sem restrições de direitos de autor conhecidas (domínio público), http://commons.wikimedia.org/wiki/File:NAS-126_Ulmus_americana.png
- (c) yaoshawn, alguns direitos reservados (CC BY-NC), uploaded by yaoshawn
- (c) Henryhartley, alguns direitos reservados (CC BY-SA), http://commons.wikimedia.org/wiki/File:Img_ulmus_americana_2209.jpg
- (c) Dr Fox, USDA, alguns direitos reservados (CC BY-SA), http://commons.wikimedia.org/wiki/File:Photo_of_the_bark_of_the_American_Elm_cultivar_%27Delaware%27.png
- (c) Alice Roy-Bolduc, alguns direitos reservados (CC BY-SA)
Mais informações
- BioDiversity4All taxon page
- African Plants - a photo guide
- Atlas of Living Australia
- Biodiversity Heritage Library
- BOLD Systems BIN search
- Calflora
- CalPhotos
- eFloras.org
- Flora of North America (beta)
- Global Biodiversity Information Facility (GBIF)
- Go Botany
- HOSTS - a Database of the World's Lepidopteran Hostplants
- IPNI (with links to POWO, WFO, and BHL)
- Jepson eFlora
- Maryland Biodiversity Project
- NatureServe Explorer 2.0
- OregonFlora.org
- SEINet Symbiota portals
- Tropicos
- USDA PLANTS database
- VASCAN by Canadensys
- World Flora Online
