Species

Common name

Photo

ID tips

#BarkingUpATree Twitter link

Acer pensylvanicum

Striped maple

Note the namesake and distinctive light green/dark green vertical stripes in the bark, along with the diamond-shaped lenticels

In addition to bark, pay attention to leaves and branching architecture to ID striped maple. Like other maples, the branching is opposite. The leaves are soft, doubly serrate, three lobed, and fairly distinct among maples.

https://twitter.com/lars_brudvig/status/1428055716065988610?s=20

Acer rubrum

Red maple

Note the gray bark, broken into randomly distributed vertical strips. Strips are prominent on this medium sized individual, with the bark neither smooth nor super-flaky

Red maple bark is smooth and gray on young trees. Vertical strips form with age. Bark on old trees can be gray to gray-brown and flakey, with the tips of the pronounced vertical strips detaching and curling outward.

To ID red maple, also key in on leaves and branches. Like other maples, branching is opposite. Leaves have 3 main lobes + white back. Silver maple (A. saccharinum) has similar bark + white back leaf, but 5 main deeply indented lobes.

https://twitter.com/lars_brudvig/status/1377319935970512900?s=20

Betula papyrifera

Paper birch

Paper birch’s white, papery bark and prominent lenticels are hard to mistake through much of its range. Look for the glossy (not chalky) and peeling bark to tell it from gray birch (Betula populifolia) in portions of the northeast.

https://twitter.com/lars_brudvig/status/1357041562077827072?s=20

Carya glabra

Pignut hickory

Note the gray bark that forms vertical strips, which interlace with each other, and are broken horizontally. The strips of bark are a little bit shaggy (detached at the ends)

To tell hickories apart, look at bark, leaves, and buds. Pignut’s bark is less shaggy than shagbark, but more so than bitternut or mockernut. It has compound, alternate leaves (like all hickories) with 5 or 7 leaflets + smallish green buds

https://twitter.com/lars_brudvig/status/1369725222199439364?s=20

Carya ovata

Shagbark hickory

Mature shagbark hickories are recognizable by their namesake bark, but younger individuals have smooth bark. Individuals of all ages have large buds that erupt colorfully in the spring.

https://twitter.com/lars_brudvig/status/1273330207001280513?s=20

Carya tomentosa

Mockernut hickory

Note the gray or brownish gray bark and wavy ridges, forming diamond-shaped furrows - common features for many hickories.

How can you tell mockernut hickory from other common hickory species? Its bark is less exfoliating (shaggy) than shagbark or pignut and ridges are more rounded off than most species, including bitternut and red. Leaflet # is also helpful, with 7-9 on mockernut.

https://twitter.com/lars_brudvig/status/1329137642521366528?s=20

Cornus florida

Flowering dogwood

Note the blocky gray-brown bark, which shows reddish-brown where broken off. The bark pattern is pretty distinctive. Some say it looks like alligator skin!

https://twitter.com/lars_brudvig/status/1288550311146266625?s=20

Fagus grandifolia

American beech

American beech has silvery bark which remains smooth even when trees are old. You may know it best for unfortunate carvings, which remain as scars in the bark for many years. Please leave beech bark beautiful!

https://twitter.com/lars_brudvig/status/1273332536253517824?s=20

Juglans nigra

Black walnut

Note the dark brown to grayish-black bark that forms ridges shaped like V’s and Y’s (upside down or right side up)

In addition to its bark, look for the pinnately compound (leaflets all come off one line) leaves with 15-23 leaflets, distinctive fruits, and spicy pungent odor. In fact, most parts of the tree have this odor, except for the nuts themselves.

https://twitter.com/lars_brudvig/status/1298696885943902208?s=20

Ostrya virginiana

Ironwood/American hophornbeam

Note the grayish-brown bark, with long, vertical, flakey strips that are loose on the ends. The bark is thin on young trees and somewhat thicker and less flakey when older

In addition to bark, pay attention to ironwood leaves. These are simple and alternate, with parallel veins and are doubly-serrated (each tooth along the margin has smaller sub-teeth). Lower leaf surface is fuzzy (not rough).

https://twitter.com/lars_brudvig/status/1397613923097010183?s=20

Picea glauca

White spruce

Note the gray, thin bark, which forms rounded scales or plates. Newly exposed areas of bark are salmon pink

The spruces are tricky to tell apart by their bark. Look for newly exposed bark, which for white spruce is salmon pink, distinguishing from black spruce (olive green) and Norway or red spruce (reddish-brown).

Pay attention to needles to tell spruces from other similar species (e.g., firs, hemlock). Spruce needles are held on ‘pegs’ and are diamond-shaped (not flat) in cross section

In MI, young white fir shoots are smooth, whereas black spruce’s are fuzzy.

Another good (though imperfect) tell for white vs black spruce is hydrology. Are your feet wet? White spruce is typically found in uplands. Black spruce is typically found in low, wet areas.

https://twitter.com/lars_brudvig/status/1344358091345825792?s=20

Pinus banksiana

Jack pine

Note the thick, grayish bark with irregularly shaped scales. Gray bark all the way up the trunk on older individuals helps distinguish jack pine from the otherwise similar Scots pine, which shows orange up the trunk

In addition to its bark, look for short needles in groups of two (the similar pitch pine has 3) and cones sealed with resin and typically pointing down the stem, (cones on the similar lodgepole pine do not point down the stem).

https://twitter.com/lars_brudvig/status/1308828787539349505?s=20

Pinus palustris

Longleaf pine

Note the flakey bark, which helps distinguish this species from other co-occuring pines (e.g., slash, loblolly)

https://twitter.com/lars_brudvig/status/1283477025123184648?s=20

Pinus resinosa

Red pine

Note the namesake reddish bark which forms jigsaw piece-like blocks. The surface of the bark becomes very flaky as individuals age (like this one - it's an old individual!)

A helpful ID characteristic to focus on with pines is the number of needles in each cluster (or fascicle). For red pine, this number is two. The needles are also long and relatively thick. Together, these distinguish from white pine (5 thin needles per fascicle).

https://twitter.com/lars_brudvig/status/1334211203791515651?s=20

Pinus strobus

White pine

Note the gray to reddish-brown bark of this medium aged individual, with vertical blocks of bark that fit like puzzle pieces. Young trees have smooth gray bark and old individuals more deeply ridged bark

In addition to the bark, Eastern white pine can be ID'd by its needles which are bluish-green and flexible and come in five 5 needle bundles (fascicles). Remember 5 needles, like the five letters in white!

https://twitter.com/lars_brudvig/status/1293624742004559872?s=20

Pinus sylvestris

Scotch pine

Note the dark gray-brown bark with thick scales and orange showing through where this individual was injured

To ID Scotch pine, look at bark, needles and cones

First needles. These are short and come in groups of two. This will help you tell Scotch pine from many other pines, with a few exceptions like jack (P. banksiana) and lodgepole pine (P. contorta).

Next, cones. Unlike jack and lodgepole pine, Scotch pine does NOT have serotinous cones sealed shut with resin (which are an adaptation to fire).

Third, bark, and this is the kicker. Scotch pine bark is similar to other pines low on the trunk, but is bright orange up the trunk and on branches. On older individuals, this is a dead giveaway.

https://twitter.com/lars_brudvig/status/1390003952327008256?s=20

Pinus taeda

Loblolly pine

Note the thick, blocky bark (forming plates in older trees), which helps to distinguish from the other southern pines, as do the intermediate length needles

https://twitter.com/lars_brudvig/status/1318975905486802946?s=20

Populus deltoides

Cottonwood

Note the gray bark (silver or brownish gray when young and dark gray when old), which forms wavy vertical ridges in young trees and becomes deeply furrowed with puzzle piece-like blocks as trees age

The scientific name of cottonwood, Populus deltoides, refers to the triangular or 'deltoid' shape of its leaves. The shape and coarse, rounded, and often hook-shaped teeth are helpful with ID, as are the resinous buds.

Eastern cottonwood leaves are flat at the base and have flat petioles, causing them to flutter in the breeze.

https://twitter.com/lars_brudvig/status/1324062666864906245?s=20

Populus grandidentata

Big-tooth aspen

Note this larger tree’s dark gray-brown bark with deep furrows and rounded ridges. Smaller trees have light colored bark, with tan, green or yellow tinge; orange inner-bark is often visible

To ID big-tooth aspen, pay attention to bark and leaves. Like the similar quaking aspen (Populus tremuloides) the light-colored bark of young trees remains high up the stem as trees age. Both species also have diamond-shaped lenticles, most visible when young.

What tells big-tooth from quaking aspen is the leaves. Quaking has many small teeth on the leaves, whereas big-tooth (as the name suggests) has larger and fewer teeth. Both have flattened petioles that make leaves flutter in the wind.

https://twitter.com/lars_brudvig/status/1402687441828470788?s=20

Pyrus calleryana

callery pear

Note the gray-brown, slightly ridged bark, broken into randomly snaking vertical strips. Lighter gray shows through where the outer bark layer has flaked off

You may be seeing a lot of callery pear right now, with its striking display of white flowers in the spring

Also note the egg-shaped leaves, which don’t lay flat, and little pear fruits in fall, which wrinkle in winter.

https://twitter.com/lars_brudvig/status/1382393271100526600?s=20

Quercus alba

White oak

The bark is light gray in color (note: the common name refers to the wood) and ranges from flakey to blocky as trees age. Bark on the upper branches of older individuals can look like shingles

Oaks come in two groups. The white oak group (including Quercus alba) have rounded tips to the leaf lobes and the red oak group (including Quercus velutina, here) have pointed tips. All oak have clusters of buds at the twig tips.

https://twitter.com/lars_brudvig/status/1339284215028998150?s=20

Quercus bicolor

Swamp white oak

Swamp white oak is a tricky bark ID, being similar to closely related bur and white oak

Leaves easily distinguish them, though, with swamp white oak leaves green above and whitish below (bicolor!)

https://twitter.com/lars_brudvig/status/1273334484025380864?s=20

Quercus incana

Blue jack oak

Note the very dark brown bark, with ridges broken into squarish, but irregularly shaped small blocks

In addition to bark, pay attention to leaves to ID blue jack oak. Its leaves are elliptical and pale green above. Below, they are slightly fuzzy and blueish green, with the color leading to the common name.

Blue jack oak is a member of the red oak group. Though its leaves don’t look like some others in the group, like northern red oak (Q. rubra), you can still find the characteristic point at the leaf tip.

https://twitter.com/lars_brudvig/status/1417907783693918213?s=20

Quercus margaretta

Sand post oak

This species’ bark has gray or gray-brown ridges that develop with age, beginning as scales (smaller overlapping sections) on younger individuals

In addition to bark, pay attention to leaves when IDing sand post oak. The leaves have two distinct lobes, giving them a cross shape, though less symmetrically or distinctly so than in close relative post oak (Q. stellata).

https://twitter.com/lars_brudvig/status/1410297282357043214?s=20

Quercus rubra

Northern red oak

Note the light, almost silver-colored flattened ridges and darker furrows on this larger individual. The shiny ridges extend all the way down the stem

Like other members of the red oak group (Section Lobatae), northern red oak’s leaves have points at the tips of the lobes. The leaves are glabrous (smooth) above and mostly so below.

The shiny, flat ridges that go all the way down the stem are a great way to tell northern red oak from other similar species. Looking up the stem, many say these ridges look like ski tracks.

Another good way to tell northern red oak from black oak is by the inner bark, which is pink for northern red oak and orange for black oak.

https://twitter.com/lars_brudvig/status/1412834149958754307?s=20

Quercus stellata

Post oak

Photo: Joe Buck

Note the dark gray bark with prominent ridges and deep furrows. The bark is broken into vertical blocks, which are pronounced on this older individual. The bark is not flakey

Post oak's bark is similar to close relative white oak. Look for cross-shaped leaves with hairy undersides on post oak to tell the two apart. The hairs on post oak’s leaves are star shaped, leading to the stellata in its scientific name.

https://twitter.com/lars_brudvig/status/1349431792701468673?s=20

Sassafras albidum

Sassafras

Thuja occidentalis

Northern white cedar

Note the grayish bark, with brown showing through in places. The bark is extremely fibrous, forming vertical strips that can twist around the trunk, intersecting in places

Northern white cedar is easily ID’d by its leaves. It’s an evergreen conifer, but without needles. Rather, it has tiny scale-like leaves - the smallest bits you can see in this photo. Arranged in overlapping rows, they form larger flat sprays.

https://twitter.com/lars_brudvig/status/1313902849718464514?s=20

Tsuga canadensis

Eastern hemlock

Note the reddish brown to reddish gray bark, broken into irregular vertical blocks by deep furrows in this old individual. Bark shows red when the surface is chipped off

Also helpful for eastern hemlock ID are the short, flat needles. These are arranged in two rows, forming a flat plain along the stem

https://twitter.com/lars_brudvig/status/1303756812177604617?s=20

Ulmus americana

American elm

The bark of American elm is brown to gray-brown, with vertical strips, and is spongy to the touch. In cross section, pieces of bark have alternating light and dark layers.

https://twitter.com/lars_brudvig/status/1273331307406340096?s=20

Zanthoxylum clava-herculis

Hercules’ club

Photo: Maia Larson

The bark’s corky spines are really distinctive and help tell this species from most others in its range

A species that can be confused with Hercules' club is devil’s walking stick (Aralia spinosa). Look for pinnately compound leaves on the former and bi-pinnately compound on the latter.

https://twitter.com/lars_brudvig/status/1359578301245890571?s=20