Colorado Master Gardenersm Program

Colorado Gardener Certificate Training

Colorado State University Extension

CMG GardenNotes #153

Identifying Broadleaf Flowering Trees and Shrubs

Outline: Leaf characteristics, page 1

Arrangement on stem, page 1
Leaflet arrangement on petiole, page 2
Venation, page 2
Leaf shape, page 2
Leaf texture, page 4
Stem characteristics, page 4
Bud type, page 4
Leaf scar and bundle scar, page 5
Stem surface texture, page 5
Internal stem features, page 6
Fruit, page 6
Characteristics of common woody plant families, page 9

Identification of broadleaf trees and shrubs is a skill mastered with practice and
knowledge of the plant families. Most trees and shrubs can be readily identified to
family and genus with a basic knowledge of the plant’s characteristics and the use
of a key. There are always a few exceptions with plants that do not look like their
relatives. Identification to a specific epithet requires more skill and a closer look at
plant characteristics. Identification to variety and cultivar is difficult to
impossible, as the defining characteristics may not be clearly observable from plant
samples. Most keys start with leaf arrangement and shape.

Leaf Characteristics
Arrangement on Stem [Figure 1]

• Alternate – Arranged in staggered fashion along stem (willow)

• Opposite – Pair of leaves arranged across from each other on stem (maple)
• Whorled – Arranged in a ring (catalpa)

Figure 1. Leaf arrangement on stem

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Leaflet Arrangement on Petiole [Figure 2]

• Simple – Leaf blade is one continuous unit (cherry, maple, and elm)
• Compound – Several leaflets arise from the same petiole

o Pinnately compound – Leaflets arranged on both sides of a common

rachis (leaf stalk), like a feather (mountain ash)
o Palmately compound – Leaflets radiate from one central point (Ohio
buckeye and horse chestnut)
o Double pinnately compound – Double set of compound leaflets

Figure 2. Leaflet arrangement on petiole

Note: Sometimes identifying a "leaf" or "leaflet" can be confusing. Look at the

petiole attachment. A leaf petiole attaches to the stem at a bud node. There is no
bud node where leaflets attach to the petiole.

Venation [Figure 3]
• Pinnately veined leaves have a central vein down the center with veinlets
branching off and extending to the edge. [elm, peach, and linden]
• Palmately veined leaves radiate veinlets out in a fan-shaped pattern from a
central point at the petiole (leaf stem). [maple, mulberry, and poplar)]

Figure 3. Leaf venation

Leaf Shape
Leaf shape is a primary tool in plant identification. Descriptions often go into
minute detail about general leaf shape, and the shape of the leaf apex and base.
There is no magic line where one type suddenly becomes another type; rather it is
a judgment call. When using keys, look at several leaves and be flexible in your
description. The following are common shapes as used in the Manual of Woody
Landscape Plants by Michael Dirr. [Figures 4-7]

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Figure 4. Leaf shapes

Figure 5. Tip shape

Figure 6. Base shapes

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 Figure 7. Leaf margin

Leaf Surface Texture

Look at all the surfaces, noting location, color, density and length of scales and
hairs. In addition to terms previously discussed, these terms are commonly
encountered when describing leaves.

o Ciliate – Orderly, widely spaces hairs along the edge (margin), also
called fringed
o Glandular – Hairs bearing glands
o Glutinous – Sticky to the touch
o Scabrous – Hairs very short
o Stellate – Star shaped hair (needs magnification)
o Velutinous – Dense hairs of equal height, like velvet

Stem Characteristics
Stems contain several features important to identifying plants. Cut into the stem
to see the pith. Look at the epidermis, buds, arrangement of the nodes and any
surface coating or texture. For winter identification of woody plants, look at the
pattern of the scales on the terminal and lateral buds and the shape of the leaf scars.

Bud Type
The type of bud is also used in plant identification. Figure 8 illustrates bud types
used in the Manual of Woody Landscape Plants. [Figure 8]

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 Figure 8.
Bud types

Leaf Scar and Bundle Scar Shape

Leaf scar – Mark left on stem where leaf was

attached. The shape of the leaf scar is
often used in woody plant Figure 9
identification. [Figure 9]
Heart-shaped
Bundle scar – Marks left in the leaf scar from leaf scar with
the vascular tissue attachment. The v-shaped
bundle scar
shape of the bundle scare is often used inside.
in woody plant identification. [Figure
9]

Stem Surface Texture

The surface of woody twigs may have a texture that can be used to distinguish one
plant from another. Terms used to describe the surfaces of stems can also apply to
leaves.

• Farinose – Covered with a mealy , powdery substance

• Glabrous – Smooth
• Glaucous – Having a bloom or whitish covering, often waxy
• Hirsute – Covered with coarse, stiff hairs, rough enough to break the skin
• Pubescent – Covered with hairs
• Scurfy – Covered with small scales
• Tomentose – Covered with short, matted or tangled, soft, wooly hairs
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 Internal Stem Features

Pith is the tissue found at the center of stems and roots. Pith characteristics may
provide identification clues. A diagonal cut across the stem reveals if the center of
the stem is hollow or if the pith is solid or chambered. A straight cut across the
stem reveals the shape of the pith (rounded, star or triangle). [Figure 10]

Figure 10.
Internal stem features used
in plant identification

Fruit Characteristics
Generally, the identification of trees and shrubs is done without fruit, as the fruit is
only around for a short season. However, when fruit is present, it can be a tool in
plant identification. For example, double samaras indicates maples. [Table 1]

Table 1. Examples of Fruit Found on Trees and Shrubs

1. Simple fruit – fruit formed from one ovary

A. Dry fruit

1) Dehiscent fruits (splitting open when mature)

a) Capsule – Many seeded fruits

formed from more than one
united carpels. Examples:
Deutzia (Deutzia), Forsythia
(Forsythia), Philadelphus
(Mockoranage), Rhododendron
(Rhododendron), and Syringa
(Lilac)

b) Follicle – Composed of one carpel but splits open at maturity

along one suture exposing seeds. Examples: Spiraea (Spiraea),
individual fruit of Magnolia

c) Legume (Pod) – Composed of one carpel that

splits open along two sutures (like a pea pod).
Characteristics of most members of the
Fabaceae (Leguminosae) family. Examples:
Albizia (Silk-tree, Mimosa), Cercis (Redbud),
Gleditsia (Honeylocust), Gymnocladus
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 (Kentucky Coffeetree), Laburnum (Goldenchain tree), and Robina
(Locust)

2) Indehiscent fruits (not splitting open at maturity)

a) Achene – One seeded fruit with seed attached at

only one place to the pericarp. Pericarp is very
close-fitted and does not split open, at least along
regular established lines. Examples: Calycanthus
(Sweetshrub), Chimonanthus (Wintersweet), and
Rosa (Rose) & Sunflower

b) Samara – One or two seeded

with a membranous wing.
Examples: Acer (Maples) –
double winged, Fraxinus
(Ash) – singled-winged, and
Ulmus (Elm) – small, single-
winged fruit

c) Nut – A bony, hard, one-seeded fruit. Examples

Castanea (Chestnut), Corylus (Filbert), Juglans
(Walnut) and Quercus (Oak)

d) Nutlet – A tiny nut. Example: Betula (Birch),

Carpinus (Hornbean), and Ostrya (Hophornbean)

B. Fleshy fruits

1. Berry – The entire pericarp is fleshy. Examples: Tomato, Lonicera

(Honeysuckle), and Vaccinium (Blueberry and Cranberry)

2. Drupe – the pericarp is clearly differentiated into

three layers; the exocarp is the epidermis;
mesocarp (middle layer) is fleshy; and the
endocarp (inner layer) is stony. Examples: Ilex,
Prunus (Cherry, Peach, Plum), Sassafras
(Sassafras), Viburnum (Viburnum), and numerous
other woody plants.

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 3) Pome – The pericarp is surrounded by the floral
tube which become the fleshy edible fruit.
Examples Malus (Apples), Pyrus (Pear), and
Chaenomeles (Quince)

2. Aggregate fruits – Develop from a single flower that contains many pistils.
Several of the fruits are massed on one receptacle. Examples:

o Fragaria (strawberry) – aggregate of achenes

o Liriodendron (Tuliptree) – aggregate of samaras
o Maclura (Osage-orange) – aggregate of drupes
o Magnolia (Magnolia) – aggregate of follicles
o Rubus (Raspberry) – aggregate of drupes

3. Multiple fruits – Consists of several flowers which are more or less united
into one mass. Example: Morus (Mulberry), Pineapples

Authors: David Whiting and Linda McMulkin with Joanne Jones, Alison O’Connor and Laurel Potts: Colorado State University
Extension. Line drawings by Scott Johnson
o Colorado Master Gardener GardenNotes are available online at www.cmg.colostate.edu.
o Colorado Master Gardener training is made possible, in part, by a grant from the Colorado Garden Show, Inc.
o Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating.
o Extension programs are available to all without discrimination.
o No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.
o Copyright 2009-2011. Colorado State University Extension. All Rights Reserved.
CMG GardenNotes may be reproduced, without change or additions, for nonprofit
educational use.
Minor Revisions December 2011

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Table 2. Characteristics of Common Woody Plant Families with
Alternate Leaf Arrangement on Stem
Noteworthy
Family Genera Typical Leaf Shape
Flowers and Fruit
o Flowers: male and
Betulaceae o Alnus – Alder o Simple, pinnately
female catkins
Birch family o Betula – Birch veined
o Fruit: nutlet
o Cercis – Redbud
o Simple, palmately
o Caragana – Peashrub
Fabaceae veined
o Gleditsia – Honeylocust o Fruit: Pea-like pod
Pea family o Pinnately compound
o Gymnocladus – Kentucky Coffee
o Bipinnately compound
o Sophora – Pagodatree
o Simple, pinnately o Flowers:
Fagaceae o Castanea – Chestnut veined catkin
Oak and Beech o Fagus – Beech o Simple, pinnately o Fruit: Nut
family o Quercus – Oak veined and pinnately (acorn)
lobed
Juglandaceae
o Juglans – Walnut o Pinnately compound o Fruit: nut
Walnut family
o Simple and
Moraceae
o Morus – Mulberry polymorphic (lobed o Fruit: Multiple drupe
Mulberry family
and unlobed)
o Amelancheir – Serviceberry
o Aronia – Chokecherry
o Cercocarpus – Mountain Mahogany
o Chaenomeles - Quince
o Cotoneaster – Cotoneaster
o Simple, pinnately
o Crataegus - Hawthorne
veined
o Fallugia – Apache Plume
o Simple, lobed
o Fragaria – Strawberry
o Pinnately compound
o Kerria – Kerria
o Palmately compound
Rosaceae o Malus – Crabapple
o Pair of stipules (leaf-
Rose family o Physocarpus – Ninebark
like appendage)
o Potentilla – Potentilla
common where leaf
o Prunus – Almond, Apricot, Cherry,
stalk joins stem. Stem
Peach and Plum
often have thorns or
o Pyrus – Pear
spines.
o Ribes – Alpine currant
o Rosa – Rose
o Rubus – Blackberry and Raspberry
o Sorbus – Mountain Ash
o Spiraea – Spiraea
o Fruit: tiny, often
o Simple
o Populus – Aspen, Poplar and catkin
Salicaceae o Simple and palmately
Cottonwood o Seeds wind
Willow family lobed
o Salix – Willow dispersed with the aid
o Stipules at leaf base
of long hairs
o Flowers: Large
Sapidaceae o Pinnately or
o Koelreuteria – Raintree panicles of yellow
Soapberry family bipinnately compound
flowers
Tiliaceae
o Tilia – Linden o Simple
Linden family
Elm fruit
small samara
Ulmaceae o Celtis – Hackberry o Simple, pinnately with disc
Elm Family o Ulmus – Elm veined shaped wing

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Table 3. Characteristics of Common Woody Plant Families with
Opposite Leaf Arrangement on Stem
Noteworthy
Family Genera Typical Leaf Shape
Flowers and Fruit
o Fruit: two-winged
samaras
o Simple and palmately veined
and lobed
Aceraceae
o Acer -- Maple and Box Elder o Pinnately compound and
Maples family
pinnately veined
o Simple and pinnately veined.

o Lonicera – Honeysuckle
o Simple, pinnately veined
o Sambucus – Elders
Caprifoliaceae o Simple and palmately veined
o Symphoricarpos – o Fruit: usually fleshy and
Honeysuckle family and lobed
Snowberry, Coralberry and berry-like
o Pinnately compound
Buckbrush
o Leaves lacking stipules
o Viburnum -Viburnum

o Flowers: Often fused

petals form a corolla tube
o Fruit: berry, drupe or
o Forsythia – Forsythia capsule.
o Simple, pinnately veined o Ash has
Oleaceae o Fraxinum – Ash
o Pinnately compound (ash) single-
Olive family o Ligustrum – Privet
o Without stipules winged
o Syringa - Lilac
samara.

Cornaceae
o Cornus – Dogwood Simple, pinnately veined o Fruit: drupe
Dogwood family

o Flower: Often a showy

Hippocastanaceae o Aesulus – Horsechestnut and
Palmately compound cone of flowers
Horsechestnut family Buckeye
o Fruit: nut-like capsule

Platanaceae o Platanus – Planetree and Simple, palmately veined and

Sycamore family Sycamore lobed

Characteristics of Common Woody Plant Families with

Whorled or Opposite Leaf Arrangement on Stem
Noteworthy
Family Genera Typical Leaf Shape
Flowers and Fruit
Bignoniaceae
o Fruit: long pod
Trunpet Creeper o Catalpa – Catalpa o Simple
capsule
family

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