and Deciduous Forest Trees

of Southern Ontario

Platanus occidentalis

Location in Ontario: Sycamore, a Carolinian Tree grows in small pockets throughout the Carolinian Zone of the Deciduous Forest Region.

Row of Sycamores, Ruthven Park, Haldimand

Genus Platanus: These are all tall trees commonly known as plane trees. The hybrid London Plane Tree has been planted throughout the world. The leaves are alternate and simple with lobes. Trees are monecious, with male and female flowers in separate round balls. The fruit is a group of achenes that form an aggregate ball. The bark is distinctive, peeling off readily to produce a mottled scaly appearance.

Sycamore grows on rich soils along creeks and rivers. It will also grow on poorly drained soil, such as in swamps.

Landscape Use:
Sycamore is a large, relatively fast growing, showy tree with unusual mottled bark and spherical seed aggregates which persist on the branches into winter.

TREE FACT: Sycamore is also known as "American Plane Tree". One of Ontario's largest trees, it is easily identified by its unusual bark and seed balls.

Leaves: The leaves leaves have 3 or 5 lobes. The edges have large wavy teeth.

FALL COLOUR WATCH:  yellow to brown

Size: This very large tree can reach over 30 metres in height and live more than 250 years! The diameter can be 2 metres or more making this the largest hardwood of the Deciduous Forest Region by bulk (considering height and width).

TREE FACT: This is the largest hardwood of the deciduous forest by bulk (considering height and width).

Bark: The bark is mostly smooth and brownish, but has large thin pieces flaking off to show a whitish colour beneath. This gives the tree a mottled or blotchy look.

Interesting bark patterns

Flowers: Monoecious with male (pollen) flowers and female (seed) flowers on the same tree. Pollen flowers are inconspicuous, yellowish-green and clumped together in a ball-like structure (aggregate). Seed flowers are grouped together in a reddish aggregate. Flowers appear in May.

Fruit: Individual seeds are achenes (hairy, tufted mini-nuts). Seeds are yellowish, hairy and club-shaped. Seed aggregates are spherical in shape and hang on the tree into winter. Seed are produced every year after 10 years of growth, but are sensitive to late frosts. 

Seed aggregates

Seed aggregates hanging on the tree in winter.

TREE FACT: Sycamore is also known as "Buttonwood", referring to the fact that Sycamore wood was used to make buttons in pioneer days.  

Wood: The wood is medium hard, but weak.
Specific gravity: 0.49
Janka Hardness: 770 lb
Wood Comparison Chart
The wood is used for cabinets and wood trim. Early settlers used a slab from the trunk of a large tree to make a cutting block. The slab was sanded smooth and legs were added.

A line of Sycamores in winter along Highway 24, Norfolk County