Tree Identification Techniques Massachusetts Qualified Tree Warden - - PowerPoint PPT Presentation

Tree Identification Techniques

Massachusetts Qualified Tree Warden Course

Learning Objectives

• Recognize why tree ID is important
• Recognize principles of ID and classification,

including binomial nomenclature

• Identify common tree parts

Importance of Tree ID

• Communicate with staff and contractors
• Understand species responses to stresses

(drought, damage, construction, etc.)

• Insect & disease susceptibility

Binomial Nomenclature Acer saccharum

Genus (plural genera) Species (specific epithet)

Acer saccharum

Binomial Nomenclature

• Lower case

(unless proper noun)

• Many common names

sugar maple hard maple rock maple common name

• Italics
• When talking about

plants, also called “botanical name”

Acer saccharum Latin name

Binomial Nomenclature

• Variety – within a species, there may be groups
• f plants that retain certain characteristics
• Common name: Drummond red maple

Genus Species Variety Name of Variety Acer rubrum var. drummondii

Binomial Nomenclature

• Cultivar (short for ‘cultivated variety’)
• Common name: red maple ‘Columnare’

Genus Species Cultivar Acer rubrum ‘Columnare’

Tree ID – general tips

• Start broad and narrow down possibilities
• Use all parts of the tree available to you

Leaves

Broadleaf Needle-like Scale or awl-like

Leaf Arrangement Alternate vs. Opposite

Image: massnrc.org

Alternate or Opposite?

Image: treeschool.myspecies.info/

Alternate or Opposite?

Image: treeschool.myspecies.info/

MAD-CAP-HORSE

Pneumonic to remember opposite plants. Many opposite plants fall under this pneumonic.

Maple – Ash – Dogwood Caprifoliaceae (honeysuckle)

family

Horsechestnut white ash

Image from Iowa State University

Looking at Leaves

Parts of a Leaf

Leaf blade

Image from Norton-Brown Herbarium, University of Maryland

Leaf Types

Simple Compound

Images: Butler.edu

Compound leaf

Simple vs. Compound Leaves

Simple leaf

Images: Butler.edu

Simple Leaf

Image from Norton-Brown Herbarium, University of Maryland

Compound Leaf

Image from Norton-Brown Herbarium, University of Maryland

Leaf Venation

American elm

Pinnate venation

Image from Northern Forest Atlas, http://northernforestatlas.org

Leaf Venation

sugar maple

Palmate venation

Image from Northern Forest Atlas, http://northernforestatlas.org

Leaf Margins

Leaf margins may be entire (smooth), toothed, or lobed

Leaf Margins

Leaf Margins

Leaf Shapes

What to look for…

Palmate or Pinnate? Leaf margin Simple or compound? Opposite or alternate arrangement ? Leaf Shape Lobes and sinuses

Entire Serrate

Other things to look for

• Form/Habit
• Bark
• Flowers
• Fruits and Seeds
• Twigs
• Buds and leaf scars

Image: Bates.edu Image: Mollie Freilicher

Form

Image: Mollie Freilicher

Form

Young Old

Image: Mollie Freilicher Image: Chris Bersbach

Bark

Images: Mollie Freilicher

Old

Young

Bark

Looking at Twigs

Image: Mollie Freilicher

Twigs

Image: Mollie Freilicher

Leaf Scars

Tree of heaven (Ailanthus altissima)

Leaf Scars

Leaf Scars

Image: Mollie Freilicher Image: Minnesotawildflowers.com

Buds

Red maple (Acer rubrum)

Images: Mollie Freilicher

Norway maple (Acer platanoides) Serviceberry (Amelanchier sp.)

Flowers

Honeylocust (Gleditsia triacanthos

• var. inermis)

Red oak (Quercus rubra) Crabapple (Malus spp.)

Fruit

Ash Tree ID Fraxinus spp.

Compound leaf Opposite

Ash Tree ID

• Furrowed bark
• Fruit is a one-winged samara

Ash Tree ID

Green Ash and White Ash

• Green Ash – common street

tree –Average 5% of street tree population

• White ash – often naturally

growing

• Know what looks “normal”

Normal ash bark Woodpecker- damaged ash bark(symptom

• f eab)

Putting it all together

Dichotomous key

Use all Parts of the Tree Available

• Form/Habit
• Bark
• Flowers
• Fruits and Seeds
• Twigs
• Buds and leaf scars
• Habitat – street tree or

natural area?

• If you are totally unsure, use

a key.

TREE IDENTIFICATION – SESSION 2

September 25

• Leaves like sugar maple,

but are usually larger, usually with 5-7 lobes.

• Snap petiole for white

milky sap

• Bark - gray to brown and

furrowed

• Samaras of a Norway

maple have a wide angle

Norway maple

Acer platanoides

Sugar maple

• Opposite
• 5 lobes, fine teeth along

margin

• Pointy buds
• Samara 80-90 degree

angle

• No milky white sap from

petiole

• Furrowed bark

Acer saccharum

Eastern white pine

• Evergreen needles,

3-5 inches long

• Needles in bundles of 5
• Cones 4-7 inches long,

resinous

• Bark, smooth when young,

becoming ridged and furrowed

• Large tree (100+ feet),

horizontal branch habit

Pinus strobus

Northern Forest Atlas Northern Forest Atlas

• Leaves are large, thin, and

papery (not glossy), with shallow sinuses small bristles

• n the lobe tips.
• Leaf tips are pointy
• Red oak can be identified by the

“ski trail” lines on bark.

• Acorn is larger than most other
• aks. Acorn cap is flat, like a

saucer, covers about a quarter

• f the nut.

Northern red oak Quercus rubra

American elm

• Vase-shaped habit
• Leaves have unequal bases
• Leaf margins are doubly-

serrate

• Fruit is a round samara
• Buds flattened against twig
• State tree of

Massachusetts

Ulmus americana

TREE IDENTIFICATION – SESSION 4

October 23

Cherry

• Small tree
• Recognized by its most

distinctive feature- smooth, shiny, red-tinted bark with red horizontal stripes

• Alternate leaves, finely

toothed

• Spring flowers, white, pink

Prunus spp.

Oregon State

Ginkgo biloba

• Easily distinguished by

small, 2-3 inch long, fan-shaped leaves

• Gawky, irregular shape

with large branches

Ginkgo

London planetree & sycamore

Platanus spp.

• Large tree
• Alternate, simple leaf,

reminiscent of maple leaf, up to 9 inches wide

• Bark-blocky and exfoliating,

showing light inner bark

• Fruit: ball-shaped, hang

down, singly or in pairs

White oak

Quercus alba

Northern Forest Atlas Northern Forest Atlas Northern Forest Atlas Wikipedia

• Large tree, rounded

form in open

• Alternate, simple leaf

with rounded lobes

• Acorn: elongated, cap

covers ¼ of acorn

• Bark: whitish, ashy,

sometimes blocky on

• lder trees

Littleleaf linden

Tilia cordata

• Distinct uneven heart-

shaped leaf, smaller than leaf of American linden

• Fragrant flowers
• Fruit has a leaf-like bract
• Canopy shape often

resembles a tear drop (triangular in shape)

Joseph OBrien, USDA Forest Service, Bugwood.org Richard Webb, Bugwood.org

TREE IDENTIFICATION – SESSION 5

November 6

Silver maple

• Opposite
• Leaf has 5 deeply cut

lobes, bright green above, silver below

• Red petiole, red buds
• Mature bark shaggy,

furrowed

Acer saccharinum

• T. Davis Sydnor, The Ohio State

University, Bugwood.org Rob Routledge, Sault College, Bugwood.org Tom DeGomez, University of Arizona, Bugwood.org Paul Wray, Iowa State University, Bugwood.org

Honeylocust

• Pinnately-compound leaves
• Hardy and common street

tree

• 6-8 inch long fruits, resemble

large, brown bean pods.

• Bark is gray-brown to bronze,

smooth with horizontal lenticels, later breaking into long, narrow, curling plates

Gleditsia triacanthos var. inermis

Pear

• Medium-dark green shiny

leaves with symmetrical curves ending at petiole.

• Small brown fruits, appear

during summer and remain into fall.

• Grows very upright, with a

conical, narrow shape and narrow branching angles

Pyrus spp.

Pin oak

Quercus palustris

• Distinct habit – low

branches droop, middle are horizontal, upper branches point upward

• Leaf 5-7 deeply cut,

U-shaped lobes

• Acorn: Shallow cap, covers

¼ of nut

Northern Red Oak vs Pin Oak

• Shallow V-shaped

sinuses

• 1” long acorn
• Bark: Smooth

when young, wide ridges when

• ld “ski trails”
• Deep U-shaped

sinuses

• ½” long acorn
• Bark: Smooth

when young, thin ridges when old

Zelkova

• Vase-shaped habit
• Alternative to American

elm

• Leaf with scalloped margin
• Bark- as tree ages,

becomes gray-brown and peely

• Requires proper pruning;

poor branch attachments

Zelkova serrata

Cherry vs. Elm vs. Zelkova

• Smooth shiny

red bark with horizontal stripes

• Criss-cross ashy

grey-brown bark

• Smooth reddish

brown bark, exfoliates with age

• Shiny, finely-

toothed oval leaves

• Uneven base,

doubly-toothed sharp teeth

• Dark green

leaves with scalloped teeth

Cherry vs. Elm vs. Zelkova

TREE IDENTIFICATION – SESSION 6

November 20

Serviceberry

Amelanchier spp.

• 6-20 feet tall,
• ften multi-stem
• Alternate, simple

elliptical leaf, fine-toothed

• Bark: Gray, striated,

green pith

Crabapple

Malus spp.

• Short and stout, rounded
• Leaf shape can vary

greatly, typically ovate.

• Bark: Variable, generally

smooth when young,

• lder- thin and scaly.
• Flowers: white to red

Cottonwood and Poplars

Populus deltoides and Populus spp.

• Alternate, simple, triangle-

shaped leaf with rounded teeth

• Flat petiole (all poplars)
• Big stem, big buds
• Bark: gray, blocky with

furrows and fissures

• Seeds are cottony

Red maple

Acer rubrum

• Leaf differs from the sugar

and Norway maple--has a narrower form and less prominent teeth.

• Leaf is typically 3-lobed,

sometimes weakly 5-lobed.

• Also characterized by red

petiole —although other maple petioles may have a red tinge

Distinguishing Between Common Maple Leaves

Norway Red Silver Sugar

5 or 7 sharp-toothed lobes. Smooth margins, milky sap 3 or 5 toothed lobes. Reddish petiole 5 thin lobes, deep sinuses 5 lobes, blunt points

TREE IDENTIFICATION

A few common trees that we didn’t have time to include in our class sessions, but that you likely encounter in your communities

Eastern Hemlock

Tsuga canadensis

• Flat needles, white dots
• n sides of midrib,

finely toothed toward tip

• Bark becomes gray and

furrowed

• Small cones

Arborvitae

Thuja occidentalis

• Form: Upright, conical
• Scale-like, flattened

leaves

• Bark is thin, brown,

shredded

Richard Webb, bugwood.org Northern Forest Atlas

Horsechestnut

• Opposite, palmately

compound leaf with 5-7 leaflets

• Habit-branches slope

down, then up at tips

• Bark—gray, blocky,

exfoliating to show orange inner bark

• Large, sticky terminal bud
• Panicles of white flowers

Aesculus hippocastanum

Richard Webb., Bugwood.org Chris Evans, University

• f Illinois, Bugwood.org

Keith Kanoti, Maine Forest Service, Bugwood.org Richard Webb, Bugwood.org Paul Wray, Iowa State University, Bugwood.org

Hybrid with pink flowers (Aesculus x carnea)

Colorado Blue Spruce and Other Spruces

• Needles ¾ to 1 ¼ inch long, blue-

green, 4 sided, resin smell

• Leaves attached to twig by leaf

peg

• Long cones, up to 4” long,

flexible scales

• Bark: Gray-brown, becoming

flaky with age

Picea pungens

Richard Webb, Bugwood.org Elmer Verhasselt, Bugwood.org Tom DeGomez, University of Arizona, Bugwood.org

Leaf pegs visible (on black spruce)

Northern Forest Atlas

Norway spruce,

Keith Kanoti, Maine Forest Service, Bugwood.org

Hawthorn

Crataegus spp.

Northern Forest Atlas Northern Forest Atlas Northern Forest Atlas

• Small tree, rounded form
• Alternate simple lobed leaves,

finely toothed

• Thorned and thornless varieties
• Spring flowers: white, pink, red