What are the Tree Species Pages?
The Tree Species Pages are a series of interactive web pages about trees in Toronto's parks and other green spaces. The project grew out of the Trees for Toronto project, a collaboration between the Royal Ontario Museum (ROM) and City of Toronto Urban Forestry.
The Tree Species Pages are similar to pages in a field guide. You can find out the tree's names (English and French common names(s) and the scientific or Latin name), plant family and origin. This information and a line drawing of the leaf can also be viewed by clicking on View the Plaque.... Identification plaques have been fixed to trees in some City of Toronto parks so you can also visit the tree in question. Click on Where Can I See...? to find links to maps of parks that have trees bearing plaques.
A description of the species starts with a summary of distinguishing features in four sections: the woody bits, the leaves, the flowers and the fruit. Click on Read more about... for more detail and click the images to enlarge them. Fascinating Facts offers tidbits like how a tree got its name, where it originated, and how it is used. This Tree in Toronto focusses on the history of the species in Toronto and whether it is appropriate for your front lawn.
This is an ongoing project. New species pages will be posted as they are completed and others will grow and change as we complete descriptions and get more images through the seasons. More parks will be mapped after selected trees have received plaques. So keep visiting and explore and enjoy Toronto trees. In time, interactive Tree Species Pages will be available for all 200-plus species of trees found in Toronto.
This is an introduction to some basic tree features that are useful for identification. Note that:
Look at tree shape and size, bark texture, thorns, twigs, buds and leaf scars.
Learn more about Tree, Bark, Twigs
Flowers may be large, colourful and showy, or small, green and inconspicuous.
Learn more about Flowers
Fruits may be dry (such as pods, nuts, capsules or samaras) or have juicy flesh.
Learn more about Fruit
The leafy branches of a tree make up the crown. The shape of the crown results from the architecture of the branches, eg whether branches reach upwards or downwards.
The trunk is the main stem of a tree. It supports the branches and connects them to the roots.
Bark is like skin, it encloses the trees tissues and protects it from physical damage. Young bark is usually smooth with conspicuous pores (lenticels) that allow exchange of gases between the atmosphere and the tree.
As a tree ages and increases in girth, the bark usually becomes thicker and rougher with ridges and furrows.
Winter twigs bear tightly closed buds that contain the next season's new branches, leaves and flowers. Young twigs vary between species in thickness, colour, and texture.
Buds vary between species in size, shape and orientation. Most buds are covered with several bud scales that differ in colour, number, stickiness, and hairiness.
Terminal buds are usually larger than the lateral buds on the same twig. Since the larger buds of many species contain new flowers (and sometimes new leaves) while smaller ones contain only leaves, flowers are often borne at the tips of branches.
Lateral buds develop just above the point of attachment of the leaves on a twig (the leaf axil) so they have the same opposite or alternate arrangement as the leaves. Some species don't have a true terminal bud but a lateral bud very near the tip of the twig may be mistaken for a terminal one.
In spring, the bud swells and the scales are pushed open as the new flowers, leaves and twig emerge.
After the bud opens, the scales fall off leaving bud scale scars that encircle the twig. The twig elongates beyond them creating the next year's growth. The scars thus mark annual growth, just as annual growth rings seen in a tree stump or log do.
The distance between a set of bud scale scars on a twig reflects the amount of growth in that year, which was determined by the length of the growing season, and environmental conditions like rainfall and temperature.
Some species (eg apple, birch, ginkgo) have twigs called short shoots that extend very little in each season resulting in many compact sets of bud scale scars.
Twigs also bear leaf scars where the previous season's leaves were attached. Size, shape, and arrangement of the bundle scars (where the veins in the leaf stalk attached) vary between species.
The type of pith inside the twig varies between species and can be seen when a twig is cut lengthwise. Pith may be continuous, spongy, chambered or sectioned.
Some trees have thorns or spines on their trunks, branches or twigs to deter herbivores from eating them.
Leaves may be arranged in opposite pairs,
or staggered singly on alternate sides of the twig.
In some species, leaves may be clustered too closely to see the arrangement; however, the short shoots that bear these leaves will be either opposite or alternate.
Later in the summer, new long shoots bear leaves that are clearly opposite or alternate.
The angle between the leaf stalk and the twig is called the leaf axil. There is usually a bud at the base of the axil, though in some species the bud may be surrounded by the leaf stalk and therefore is hidden.
Look for buds in order to determine if the leaf is simple (a single blade attached to a leaf stalk) or compound (divided into a number of identical leaflets attached to a leaf stalk). There are never buds where the leaflets attach but there is always a bud where the entire leaf does. See next row for types of compound leaves.
Some species bear a pair of stipules at the base of the leaf stalk. Some, like these large stipules of tulip-tree, enclose the new leaf before it emerges. Some stipules drop off after the leaf emerges and others persist through the season (click image). Like bud scales, stipules leave a scar on the twig.
Depending on the species, leaf stalks may be short or long, green or red, round or flattened. The leaf stalks of some species, e.g. Norway maple, may be different lengths so that each leaf is in the best position to receive the sun's rays.
Compound leaves are made up of several leaflets and may be tri-foliate, with three leaflets
or palmate like a hand, with several leaflets joined at the leaf stalk
or pinnate like a feather, with several leaflets on a central rib
or bi-pinnate, twice divided.
Simple leaves may be entire with smooth edges
or with toothed edges
or with pinnate lobes, the veins extending from the tips of the lobes to the mid-rib,
or with palmate lobes, the veins extending from the tips of the lobes to the point where the leaf blade meets the leaf stalk.
Look at leaf tips, bases, edges, and overall shape. This leaf is round with a heart-shaped base, round tip, and rounded teeth on the edges.
This leaf is widest below the middle, with a tapering tip, a wedge-shaped base, and rounded teeth.
This leaf is widest below the middle and has an asymmetrical base, a long tapering tip, and sharp teeth.
This lobed leaf is as wide as long, has a straight base, a notched tip, and a smooth, untoothed edge.
This leaf has an asymmetrical base, a pointed tip, and the edges are double-toothed.
This leaf is fan-shaped, with a tapered base, and a wavy top edge divided into two lobes.
This leaf is oval (widest at the middle) with a slightly heart-shaped base, a pointed tip, and small sharp teeth.
Other leaf features are also useful, e.g. texture (hairy or smooth), venation, glands. This leaf is hairy on the underside, with prominent curved veins.
Trees that flower in the spring before or as the leaves emerge are wind-pollinated and have tiny flowers with no petals. Some species bear separate male and female flowers. The male flowers, such as these of red oak, are often clustered together in long dangling catkins. Pollen is blown from the male flowers to the female flowers, which may be on the same branch, a different branch of the same tree, or even on separate trees.
Female wind-pollinated flowers are often very hard to find. They are often borne singly or in smaller clusters than the male flowers. Note the red stigmas on these female hop-hornbeam flowers that will catch the pollen blown from the male flowers.
Some tree flowers are eye-catching and/or fragrant to attract the insects that pollinate them. Some insect-pollinated species bear their flowers flowers singly, such as this tulip-tree flower, or in small groups. Most insect-pollinated flowers bear both male and female parts and flower later in the spring or summer when more insects are active.
Other insect-pollinated species bear their flowers in clusters, usually at the tips of branches, such as these flat-topped clusters of Washington thorn flowers. Other species may have tall erect clusters, such as horse-chestnut, or long dangling clusters, such as black locust.
Fruits develop from flowers. They contain the seeds which develop from fertilized ovules in the flower's ovary. There are many kinds of fruits. Fruits with a papery wing attached to them so they can "helicopter" away from the parent tree are called samaras. Examples are elms, ashes and maples.
In legumes such as black locust, Kentucky coffee-tree, and yellow-wood, fruits are pods. Depending on the species, pods may be thick or flattened, long or short, straight or twisted. In most species, pods open along both seams, but in some, especially flat ones, the pod breaks across each section with a seed in it. The seeds inside a legume pod are called beans (poisonous in some species).
In poplars, aspen, cottonwood and willows(Populus spp), fruits are capsules borne in long clusters called catkins. The seeds released from the capsules have a small tuft of fibres which help the seeds get blown far from the parent tree.
Some fruits have a fleshy covering to attract animals which eat the fruit and disperse the seeds when they defecate away from the parent tree. Apples, pears, hawthorns and serviceberries are all fleshy fruits.
Some fruits are nuts, such as chestnut, acorn, beech and horsechesnut. The nuts of these species are either entirely or partly enclosed in a husk which, in some, is prickly.
Some fruits are in aggregates - many tiny fruits tightly packed together, such as these plane-tree fruits.
Alders bear their seeds in woody cones.
Conifer means cone-bearing. The woody cones of pines, white-cedars and other members of the pine and cypress families are not technically fruit, but they bear the winged seeds - one on each scale.
Floras and checklists
Natural Resources Canada: Trees, Insects and Diseases of Canada's Forests (tidcf)
Local community programs
General information and fact sheets
Useful Guides
Other Reference Books
Insects & Diseases
Scientific Nomenclature
Journal Articles
Generous financial assistance was received for this project from Toronto Field Naturalists.
Photography, writing, editing, design and development of the pages were undertaken by:
Botanists Tim Dickinson, James Eckenwalder and Nadia Talent provided valuable botanical consultation. Foresters Stephen Smith and Wendy Strickland shared their local knowledge of Toronto trees.
Additional images courtesy of Royal Ontario Museum Botany Image Collection. All images copyright the photographer unless otherwise noted in the credit note on the enlarged image.