Common Name: Rock Elm
Scientific Name: Ulmus thomasii
Other Names: Cork Elm, Winged Elm
Leaf: Deciduous; simple; alternate; shiny smooth dark green above, paler hairy beneath,
bright yellow in fall; leathery; 5-10 cm long; teeth incurved.
Flower: Reddish; small; no petals, 7-8 tiny sepals; clusters with central stalk
(racemes); flowers in spring before leaves expand.
Fruit: Oval, flat; 5-10 mm long; narrow; not distinct from seed case; hairy especially
on margin; shallow notch on tip; hangs in elongated clusters.
Twig: Light yellowish brown; slender; covered in fine hairs in 1st year, smooth dark
reddish-brown or ash-grey when mature; develop irregular corky ridges in 2nd year.
Bark: dark grey with red tinges; shaggy, broad flat topped ridges separated by wide
irregular furrows; surface is large irregular scales.
Wood: dark grey with red tinges; shaggy, broad flat topped ridges separated by wide
irregular furrows; surface is large irregular scales.
Facts About This Tree:
1. Sapling can continue to grow after several decades of suppressed growth under
forest canopy.
2. Rock elm wood was used for making piano frames, hockey sticks, ship building,
but is no longer used commercially.
3. Rock elms begin to produce seeds every 2-3 years starting at 20-25 years of age,
and can live to be about 125 years old.
4. Rock elm is vulnerable to Dutch elm disease, like other elms.
5. Rock elms are moderately fast growing trees but they need full sunlight to grow
quickly.
Lat, Long: 43.74452, -79.79697
Diameter (DBH): 47.6 cm
Last Year Modified: 2015
Carbon Stored in this Tree: 602.198 kg of C
Equivalent CO2: 2207.839 kg of C
Find more trees in Heart Lake Conservation Area.
Reference
1. Kershaw, Linda. 2001. Trees of Ontario. Edmonton, AB Canada. Lone Pine Publishing.
2. Farrar, J. L. 2007. Trees in Canada. ON. Canadian Forest Service.
3. Photo Credit: Ronnie Nijboer [CC0], via Wikimedia Commons.
4. Photo Credit: Ronnie Nijboer (Transferred by IKAl/Originally uploaded by Ptelea)
[CC0], via Wikimedia Commons.
Copyright 2015 Association for Canadian Educational Resources
The second lake in Heart Lake Conservation Area is known as Teapot Lake. Teapot Lake was formed by glacial action similar to Heart Lake. Although small, Teapot Lake is very deep at its centre. Water in the lake is from a deep glaciofluvial aquifer and there are no surface inflows or outflows. This has resulted in Teapot being meromictic; lacking turnover of water stratification (layers) as the seasons change. Bottom sediments are not disturbed and contain an “image-like” record of the region over the last 12,000 years.