Manitoba Maple

What it looks like

Manitoba maple is unique amongst our native maples for having compound leaves that resemble Ash leaves, with 3-9 toothed leaflets. Leaves turn yellow or yellowish-green in the fall. Young twigs have a waxy powder on them that can be rubbed off. It is a fast-growing, short-lived tree, to about 60 years old.

Where it is found

Manitoba maple is named for being the largest maple native to the Prairies, but it also grows in Southern Ontario and in the Northwest from Kenora to Thunder Bay. Female trees produce many winged seeds each year, and it has become naturalized in many cities and towns across Ontario.

Planting Tips

• Size: Up to 20 m tall
• Moisture: Adaptable from seasonally flooded areas to dry soils
• Shade: Prefers full sun
• Soil: Adaptable to many soil types

Manitoba maple has weak wood and usually requires pruning to maintain good form, so review other species for tree planting in school yards, around power lines or near homes. Manitoba Maple is best used as a restoration species for tough sites or areas where it is native.

Manitoba maple prefers floodplains and stream banks, but is also adaptable to dry, disturbed sites.

Did you know?

In the Prairies, Manitoba Maple is tapped to make maple syrup.

Image credits

• Tree: Public domain (USDA)
• Leaf: Natural Resources Canada, Canadian Forest Service
• Bark: Natural Resources Canada, Canadian Forest Service
• Fruit: Sean Fox, University of Guelph

Toxicology[edit]

A protoxin present in the seeds of Acer negundo, the hypoglycin A, has been identified as a major risk factor for, and possibly the cause of, a disease in horses, seasonal pasture myopathy. SPM is an equine neurological disease which occurs seasonally in certain areas of North America and Europe, with symptoms including stiffness, difficulty walking or standing, dark urine and eventually breathing rapidly and becoming recumbent. Ingestion of sufficient quantities of box elder seeds or other parts of the plant results in breakdown of respiratory, postural, and cardiac muscles. The cause of SPM was unknown for centuries despite the disease being well known among affected areas and was only positively determined in the 21st century.^[28][29][30] It is analogous to Jamaican vomiting sickness in humans, with both diseases sharing the same causative toxin. Ingesting Acer negundo seeds, or other parts of the plant, may therefore be toxic to humans, in large doses.

Allergenicity[edit]

Acer negundo is a severe allergen. Its pollination occurs from winter to spring, depending on latitude and elevation.^[31]

Uses

Although its light, close-grained, soft wood is considered undesirable for most uses, this tree has been considered as a commercial source of wood fiber, for use in fiberboard.

There is some commercial use of the tree for various decorative applications, such as turned items (bowls, stem-ware, pens). Primarily burl wood and injured wood, where the primary reason is this wood's reaction to injury, where the injured wood develops a red stain.