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1. Is it a woody or
non-woody plant?
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A TREE or SHRUB is a plant that contains woody
materials in its stems. The stem can live through the winter, and continue
growing in the following year. They can be full-size
trees, small
trees,
shrubs,
vines, or small plants only a few inches tall,
referred to as
Sub-Shrubs.
2. Is it a
TREE or a
SHRUB?
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A
SHRUB is usually defined loosely as a small
tree, usually with more than one main stem or trunk. It includes woody
plants down to the smallest possible, even only a few inches tall - these
are known as "
sub-shrubs".
Woody vines are also usually considered to be
SHRUBS. The size criteria refers to the normal
mature size of the plant. Thus, a young sugar maple is not a
"shrub"!
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A
TREE is what we commonly think of as a tree - tall, and
usually with a single trunk.
3. Is it a
CONIFER or a DECIDUOUS
tree?
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CONIFERS are trees & shrubs with needles: pine,
spruce, fir, cedar, juniper, and tamarack. They retain their needles
year-round (except for Tamarack).
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DECIDUOUS trees & shrubs are all others. The leaves
of DECIDUOUS trees & shrubs die every autumn and are usually shed (some species
retain some or all of their dead leaves until the following spring).
4.
Deciduous: Is it
ALTERNATE or
OPPOSITE or
WHORLED?
The terms
ALTERNATE,
OPPOSITE and
WHORLED refer to the
arrangement of leaves and twigs.
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In an
OPPOSITE-leaved tree/shrub, the leaves and stems
are arranged along the stem in pairs.
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In an
ALTERNATE-leaved tree/shrub, the leaves and stems
are arranged along the stems in an alternating fashion.
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In a plant with
WHORLED leaves, the leaves are arranged the
same as for opposite-leaved plants, except there are usually more than two
leaves in a group. In other words, where there would be a pair of leaves,
there are instead three or even more. Note that plants that have whorled
leaves often have quite a few opposite pairs as well. For this reason
species with whorled leaves are included with opposite-leaved species.
Note: Opposite-leaved trees/shrubs can
appear to be alternate at times, but you will always find an
opposite pair of leaves or twigs somewhere on the plant.
However, alternate-leaved trees/shrubs will never have any
true opposite pairs of leaves or twigs.
TREES: The only
OPPOSITE-leaved trees in Ontario are Maples, Ashes,
and Horsechestnut.
Most trees are
ALTERNATE-leaved
trees.
SHRUBS: There are many opposite and alternate-leaved shrubs in
Ontario.
5.
DECIDUOUS: Does it have
COMPOUND or
SIMPLE leaves?
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COMPOUND leaves are those that are made up of
smaller leaflets, usually 5 or more, sometimes as many as 13-15 or more.
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SIMPLE leaves are the usual single leaf.
6.
SUMMARY
In Ontario:
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CONIFERS:
Pine, Spruce, Fir, Hemlock, Larch/Tamarack, Cedar, Juniper
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DECIDUOUS:
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OPPOSITE,
COMPOUND-leaved: Ash, Horsechestnut, and one species of Maple
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OPPOSITE,
SIMPLE-leaved: Maple (except one species)
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ALTERNATE,
COMPOUND-leaved: Walnut, Hickory, Kentucky Coffeetree
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ALTERNATE,
SIMPLE-leaved: all the rest
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