Dendrology: Week 1

Alternate

1 leaf per node

Opposite

2 leaves per node

Simple

Compound

Most Common Tree Leaf Arrangement

Simple Alternate

#1 Cause of Tree Growth Placement

Shade tolerance/Intolerance

#2 Cause of Tree Growth Placement

Dryness/Wetness

#1 Tree for Wood Production

Oak

River Birch

Betula nigra

• distinct, papery, “pink” bark

• only native one in this part of TN

• grows near water

• summer fruiting

• lenticels on bark for oxygen

• can get big and bark will look grey, but limb bark should look normal

• simple alternate leaf, with teeth, very thin stem

• shade intolerant

Sugar Maple

Acer saccharum

• simple opposite leaf, pointy-toe shape, 3 lobes, no teeth

• fruit is small double samara, fruit in fall

• shade tolerant

• bark is heavy, scaly, dark brown

• beautiful fall color

• holes drilled along tree, sap, fungi

White Ash

Fraxinus americana

• opposite compound (no bud at leaflet)

• flattened tip, bud = chocolate brown

• terminal leaflet, odd pinnate

• white underleaf

• longer rachis, longer petiole

• drier area

• single samara, thicker than green

• bark furrowed, very uniform, diamond shapes, dark creamy

Green Ash

Fraxinus pennsylvanica

• opposite compound

• green underleaf

• leaflets attached closer to rachis, fuller looking, short petiole

• wetter area

• terminal leafleft, odd pinnate

• more popular in landscaping

• bark furrowed, very uniform, diamond shapes, dark creamy

• single samara, thin boat ore shape

Black Tupelo/Gum

Nyssa slyvatica

• alternate simple

• non-descript leaf

• leaf: thick and glossy OR thin and not glossy

• bark: blocky bark OR sweet gumish

• red leaves, turn early

• fruit: green or dark purple, small sphere with bad, bitter taste

• on small ones, limbs stick straight out

Eastern Redbud

Cercis canadensis

• legume family

• simple alternate leaf, heart-shaped, no teeth, tender

• fruit (legume) remains during the winter

• scaly bark, underbark is red/purple

• small, popular ornamental

• dark lavender flower in spring

• shade tolerant, very common

Cottonwood

Populus deltoides

• equilateral triangle shaped leaf, a little curve, wavy margin

• fast-growing shade intolerant

• blocky, rocky bark

• lower branches naturally self-prune

• grow very straight and upright

• only true native poplar

• grow close to water

Sweet Gum

Liquidambar styraciflua

• simple alternate, star shape, uniform, blunt teeth

• spur branches

• fruit green, then brown

• spongy, tan-brown bark

• corky ring on branch edge

• orange-red in fall

Red Maple

Acer rubrum

• teeth on margin

• red petiole or green petiole

• no fruit in fall

• similar bark, not as brown, outer limbs more smooth

• red outer stem on young leaf

• red leaves

• not very shade tolerant

2 Main Oak Groups

White Oak, Red Oak

White Oak Group

• rounded lobes, and large, regular teeth

• acorns have less tannins and smooth, hairless caps

• generally paler, sometimes appearing almost white, can be flaky

Red Oak Group

• pointed lobes with a tiny bristle at the tip

• acorns more bitter (tannins), have tiny hairs on the inside of the cap

• bark is darker, from gray to almost black, somewhat smooth with scaly ridges

The Big 5 Oaks

Northern Red, Southern Red, White, Black, 1

Water Oak

Quercus nigra

• one of the smallest acorns, fairly flat cap

• gray, platy bark, streaky

• leaf: one of smallest leaves, club shaped, variation on tree

• not very native here, not big 5

• not very water needing

Black Oak

Quercus velutina

• dark bark, dark grey

• bigger typical oak leaf shape, bristles, pointed tip, broad lobe, narrow sinus

• bigger acorn, cap goes about halfway down, shingle-like scales

Southern Red Oak

Quercus falcata

• long terminal lobe, bell-shape (southern bell)

• brown fuzzy hair

• black/grey bark

• not many acorns, very slightly bigger than water oak acorn

White Oak

Quercus alba

• lobed leaves with rounded edges

• no bristles

• post falls under this

• shaggy bark especially in middle

• important for wildlife

Post Oak

Quercus stellata

• white oak related

• rounded lobes, but a cross-shaped leaf

• different bark, not as shaggy, very knotty in comparison, hence the name

Northen Red Oak

Quercus rubra

• broad lobe, thinner and more papery

• platy bark, streaking red or black

• largest of acorns covered so far, round and very flat cap