Plants & trees
Identify a tree by its bark
Bark is what you have for five months of the year, and it is a better character than most people expect — provided you look at the trunk at chest height on a mature tree. Young bark and branch bark lie: nearly every rough-barked species is smooth for its first fifteen years. Filter by texture first, then by colour and pattern.
Narrow it down
Showing all 34 trees
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American beech
Fagus grandifolia
Smooth pale silver-grey like elephant skin, from sapling to veteran — the only large eastern tree that never develops furrows. Which is why every beech in a public park is carved with initials.
In the record 90,676 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
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Paper birch
Betula papyrifera
Chalk-white bark peeling in horizontal papery sheets, marked with dark horizontal dashes, and orange beneath the peel. The base of an old tree turns black and furrowed.
In the record 28,894 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from Canada check on GBIF
Birch identification -
River birch
Betula nigra
Salmon-pink to cinnamon bark curling off in ragged papery sheets that stay attached, giving a permanently shaggy trunk. The only birch with warm colouring.
In the record 9,412 georeferenced records · half of them Mar–Jul · most distinctive in December · mostly from the United States check on GBIF
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Shagbark hickory
Carya ovata
Long grey plates attached in the middle and curling away at both ends, so the whole trunk looks like it is coming apart. Unmistakable and unique among eastern hardwoods.
In the record 17,910 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
Identifying hickories -
White oak
Quercus alba
Pale ash-grey bark breaking into loose vertical plates and blocks with a chalky, slightly scaly surface. Lighter than any other large oak.
In the record 47,555 georeferenced records · half of them Apr–Aug · most distinctive in December · mostly from the United States check on GBIF
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Northern red oak
Quercus rubra
Dark grey with flat-topped ridges separated by shallow furrows, and — the diagnostic feature — smooth, shiny, pale grey stripes running down the ridge tops like ski trails.
In the record 226,793 georeferenced records · half of them May–Aug · most distinctive in November · mostly from the United States check on GBIF
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Black oak
Quercus velutina
Nearly black, deeply furrowed and blocky. Cut into the outer bark with a knife and the inner bark is bright orange-yellow — no other oak does that, and it was once harvested as a dye.
In the record 13,233 georeferenced records · half of them Jun–Sep · most distinctive in October · mostly from the United States check on GBIF
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Sycamore and London plane
Platanus occidentalis, P. × acerifolia
Flakes off in irregular plates leaving a camouflage of cream, olive and tan, with the upper trunk and branches almost pure white. Visible from a kilometre away in winter.
In the record 50,035 georeferenced records · half of them Feb–Jul · most distinctive in November · mostly from the United States check on GBIF
Sycamore identification -
Black cherry
Prunus serotina
Young trunks are smooth dark red-brown with conspicuous horizontal lines; mature bark breaks into small curled dark plates often described as burnt cornflakes. Scratched twigs smell of bitter almond.
In the record 288,858 georeferenced records · half of them Apr–Jul · most distinctive in May · mostly from the Netherlands check on GBIF
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Sugar maple
Acer saccharum
Grey-brown bark forming long irregular vertical plates that lift along one edge, giving a slightly shaggy but firmly attached look. Younger trunks are smooth and grey.
In the record 59,528 georeferenced records · half of them May–Aug · most distinctive in October · mostly from the United States check on GBIF
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Red maple
Acer rubrum
Smooth pale grey when young — often mistaken for beech — breaking into long thin flaking plates with age. Red buds and red twigs in winter are the reliable confirmation.
In the record 133,130 georeferenced records · half of them Mar–Jul · most distinctive in October · mostly from the United States check on GBIF
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Silver maple
Acer saccharinum
Silvery-grey bark that peels into long loose flakes curling away at both ends, giving a scruffy trunk. Softer and shaggier than sugar maple at the same age.
In the record 95,335 georeferenced records · half of them May–Aug · most distinctive in October · mostly from the United States check on GBIF
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White ash
Fraxinus americana
An interlacing net of narrow ridges forming regular diamonds — the most geometric bark of any eastern hardwood. Dead and dying ashes now often show D-shaped exit holes and blonde woodpecker flecking.
In the record 17,819 georeferenced records · half of them May–Aug · most distinctive in October · mostly from the United States check on GBIF
Ash tree identification -
American elm
Ulmus americana
Deep furrows between flat scaly ridges, and a cut through the bark shows alternating light and dark layers like a slice of layer cake. That cross-section is diagnostic.
In the record 45,426 georeferenced records · half of them Mar–Jul · most distinctive in November · mostly from the United States check on GBIF
Elm identification -
Hackberry
Celtis occidentalis
Pale grey and covered in irregular corky warts and knobbly ridges like a bad rash. No other common tree has it, so hackberry is one of the easiest winter identifications there is.
In the record 28,574 georeferenced records · half of them May–Aug · most distinctive in October · mostly from the United States check on GBIF
Hackberry identification -
Cottonwood
Populus deltoides
Massive vertical ridges and very deep furrows on old trees, pale ashy grey, with the trunk often over a metre thick. Young bark is smooth and yellow-green.
In the record 36,424 georeferenced records · half of them Apr–Jul · most distinctive in April · mostly from the United States check on GBIF
Cottonwood identification -
Quaking aspen
Populus tremuloides
Smooth greenish-white bark with a chalky bloom that rubs off on your hand, marked with black scars where branches fell, and dark furrowed only at the very base of old stems.
In the record 61,907 georeferenced records · half of them Jun–Aug · most distinctive in June · mostly from the United States check on GBIF
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Eastern white pine
Pinus strobus
Smooth grey-green with resin blisters when young; on old trees, thick dark rectangular blocks separated by deep furrows, often with pitch bleeding from wounds.
In the record 115,039 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
Pine bark identification -
Scots pine
Pinus sylvestris
The upper trunk and branches are bright orange-red with thin flaking papery plates, while the base is dark and blocky. That two-tone trunk identifies it at a distance.
In the record 1,187,370 georeferenced records · half of them Apr–Jul · most distinctive in July · mostly from Sweden check on GBIF
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Ponderosa pine
Pinus ponderosa
Huge cinnamon-orange jigsaw plates separated by deep black fissures on mature trees, and the furrows smell distinctly of vanilla or butterscotch on a warm day.
In the record 67,650 georeferenced records · half of them Apr–Jul · most distinctive in December · mostly from the United States check on GBIF
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Eastern hemlock
Tsuga canadensis
Thick cinnamon-brown bark with broad flat-topped ridges and deep furrows, and a purple-red flush inside a fresh cut. Historically stripped for tanning leather.
In the record 64,784 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
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Eastern redcedar
Juniperus virginiana
Reddish-brown bark peeling in long fibrous vertical strips that shred between your fingers, over a fluted trunk, smelling strongly of cedar when scratched.
In the record 71,990 georeferenced records · half of them Jan–Jun · most distinctive in February · mostly from the United States check on GBIF
Cedar identification -
Black locust
Robinia pseudoacacia
Deeply furrowed dark bark with ridges that cross and interweave into a rope or braid pattern, and flat brown seed pods hanging on through winter.
In the record 496,561 georeferenced records · half of them Apr–Jul · most distinctive in May · mostly from France check on GBIF
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Honey locust
Handle with careGleditsia triacanthos
On a wild tree, clusters of branched red-brown thorns growing straight out of the trunk — nothing else in North America does that. Long twisted brown pods litter the ground beneath.
In the record 139,443 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
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Sweetgum
Liquidambar styraciflua
Deeply furrowed grey-brown bark, and often corky wings running along the twigs. The spiky brown gumball fruits scattered under the tree confirm it instantly.
In the record 97,409 georeferenced records · half of them Mar–Jul · most distinctive in December · mostly from the United States check on GBIF
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Sassafras
Sassafras albidum
Red-brown deeply furrowed bark with a distinctly cinnamon cast, and twigs that are bright green and smell of root beer when scratched. The smell is decisive.
In the record 62,820 georeferenced records · half of them Apr–Jul · most distinctive in April · mostly from the United States check on GBIF
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Tulip tree
Liriodendron tulipifera
Grey bark with a fine interlacing diamond pattern on a very straight cylindrical trunk that stays branchless for many metres. Dry cone-like seed heads stand upright on the twigs all winter.
In the record 77,205 georeferenced records · half of them Apr–Jun · most distinctive in April · mostly from the United States check on GBIF
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Persimmon
Diospyros virginiana
Very dark grey-black bark broken into small, thick, regular square blocks — the standard description is alligator hide, and no other eastern tree matches it.
In the record 32,442 georeferenced records · half of them May–Aug · most distinctive in October · mostly from the United States check on GBIF
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Osage orange
Maclura pomifera
Orange-brown ridged bark with a stringy shaggy surface and stout straight thorns at the nodes. A cut shows brilliant orange-yellow wood beneath.
In the record 28,756 georeferenced records · half of them Jul–Oct · most distinctive in November · mostly from the United States check on GBIF
Osage orange identification -
American sycamore maple and Norway maple
Acer pseudoplatanus, A. platanoides
Norway maple has fine regular shallow furrows in a close vertical net over grey-brown bark; sycamore maple flakes into small squarish plates showing orange beneath.
In the record 1,327,995 georeferenced records · half of them Apr–Jul · most distinctive in June · mostly from the United Kingdom check on GBIF
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Douglas fir
Pseudotsuga menziesii
Smooth grey with resin blisters when young, becoming extraordinarily thick corky bark with deep vertical furrows and cinnamon layers visible inside — an adaptation that lets it survive ground fire.
In the record 164,367 georeferenced records · half of them Mar–Jul · most distinctive in February · mostly from the United States check on GBIF
Douglas fir identification -
Coast redwood and giant sequoia
Sequoia sempervirens, Sequoiadendron giganteum
Fibrous cinnamon-red bark up to two feet thick, soft enough to punch, deeply furrowed and fire-resistant. Nothing else in North America has bark on that scale.
In the record 25,128 georeferenced records · half of them Jan–Jun · most distinctive in February · mostly from the United States check on GBIF
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Striped maple
Acer pensylvanicum
Smooth green bark with vertical white stripes running down it, on a small understory tree. Also called moosewood. The green-and-white striping is unique.
In the record 33,473 georeferenced records · half of them May–Jul · most distinctive in May · mostly from the United States check on GBIF
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Ironwood and musclewood
Carpinus caroliniana
Smooth blue-grey bark over a fluted, sinewy trunk that looks like a flexed forearm. The ripples are in the wood, not the bark, and no other tree has them.
In the record 22,618 georeferenced records · half of them Apr–Jul · most distinctive in March · mostly from the United States check on GBIF
Nothing in this key matches every filter at once. That usually means one observation is off — a colour read in shade, or a size guessed rather than measured. Clear the filter you are least sure about and look again.
Bark changes with age, and that is the main trap
Almost every rough-barked tree begins life smooth. A twenty-year-old red oak, black cherry or white pine looks nothing like a two-hundred-year-old one, and a photograph of a sapling in a hedge will match nothing in this key or any other.
Three practical rules follow, and they fix most failed bark identifications:
- Read the main trunk at chest height, on the largest example of the tree you can find. That is the standard reference position, and every published description assumes it.
- Ignore branches entirely. Branch bark stays juvenile far longer than trunk bark, which is why the top of a Scots pine is orange and papery while the bottom is black and blocky. Both are the same tree.
- Look at the base separately. Several smooth-barked species — aspen, paper birch, beech in old age — develop dark furrowed bark in the lowest metre while staying smooth above it.
The corollary is that bark identification is much easier in a woodland with mature trees than in a hedgerow or a new plantation, and it is close to impossible on nursery stock.
The textures worth learning by name
Six textures cover almost every temperate tree, and each one is a very short list.
| Texture | What it looks like | Trees |
|---|---|---|
| Smooth at any age | Unbroken, like skin | Beech, ironwood, striped maple, young everything |
| Papery peeling | Horizontal sheets that curl and tear | Paper birch, river birch, yellow birch |
| Shaggy vertical strips | Long plates loose at both ends | Shagbark hickory, silver maple, redcedar |
| Interlacing ridges | A net of diamonds | White ash, tulip tree |
| Blocks and plates | A tiled or alligator-hide surface | Persimmon, black oak, flowering dogwood, ponderosa pine |
| Deep vertical furrows | Thick ridges, deep valleys | Cottonwood, black locust, sweetgum, Douglas fir, hemlock |
| Warty and corky | Irregular knobs and bumps | Hackberry, cork elm, sweetgum twigs |
Three of these are effectively single-species answers in eastern North America: a trunk covered in corky warts is hackberry, a trunk shedding long plates loose at both ends is shagbark hickory, and a perfectly smooth grey trunk on a large tree is beech. If you learn only those three, you can identify something in every winter woodland you walk through.
The clues that are not bark
Winter identification gets much easier once you stop looking only at the trunk. Four other things are visible in January and each is often more decisive than the bark itself.
Buds and twigs. Arrangement survives leaf fall — buds on maples, ashes, dogwoods and horse chestnuts are still opposite. Bud shape is diagnostic on its own for several genera: beech buds are long, slender and sharply pointed; the ashes have a stout black bud sitting in a crescent-shaped leaf scar; oaks cluster several buds at the tip of the twig, which no other genus does.
Fruit on the ground. The tree may be bare but its output is underneath it. Acorns, hickory nuts, gumballs, sycamore balls, catalpa pods, locust pods, samaras and cones all persist for months and settle the identification in one glance.
Dead leaves still attached. Beech, several oaks and hornbeam hold their dead leaves through the winter — a habit called marcescence — mostly on young trees and lower branches. A tree with papery tan leaves in February is a very short list.
Overall form. Elms vase outward, pin oaks droop their lower branches, tulip trees drive a single straight stem far up before branching, and honey locusts carry a broad flat crown. Silhouette works at a distance where nothing else does.
Smell and scratch, carefully
Several species are identified faster by nose than by eye, and a small scratch on a twig — not the trunk — does no harm to the tree.
- Sassafras — root beer, unmistakably, from a scratched green twig.
- Black cherry — bitter almond, from a scratched twig. That is cyanogenic glycoside, and it is why wilted cherry foliage is dangerous to livestock.
- Ponderosa pine — vanilla or butterscotch, from the deep bark furrows on a warm afternoon.
- Eastern redcedar and other junipers — pencil shavings.
- Black walnut — a sharp resinous smell from the husks and from a cut twig, which stains skin brown.
- Black oak — no smell, but bright orange-yellow inner bark under a knife cut, which nothing else in the genus shows.
Scratch a twig or a small branch, never the trunk of a living tree: a ring of damaged bark can girdle and kill it, and repeated knife cuts in a public park are how veteran trees get infected.
What bark cannot tell you
Bark is variable in ways leaves are not. The same species grown in the open, in a closed forest and in a city will produce noticeably different bark at the same age, because light and growth rate change how the outer layers split. Bark on the north side of a trunk carries more moss and lichen than the south side in the northern hemisphere, and people read the moss as texture.
Several genera cannot be taken to species from bark at all. Hickories other than shagbark, the willows, the hawthorns and most of the white oak group overlap so heavily that a professional will not attempt it. Where that is the case, this key names the group.
Damage also masks everything. Fire scars, frost cracks, canker, sun scald, old wire, woodpecker rings and the blonde flecking left by woodpeckers working an ash killed by emerald ash borer all change the surface completely. If a trunk looks like nothing in any key, check whether you are reading an injury rather than a species.
34 entries here, weighted towards the trees people actually walk past in eastern and central North America plus the major western conifers and the common European species. For anything that matters, photograph the trunk at chest height with something for scale, a twig showing buds and their arrangement, and whatever is lying on the ground underneath.
A short route to identifying a tree in February
- Look at the ground first. Nuts, cones, pods, samaras and gumballs are the fastest identification available and they are lying right there.
- Check bud arrangement on a low twig. Opposite puts you in a list of about seven groups; alternate leaves everything else.
- Read the bark texture at chest height, on the biggest specimen present.
- Step back thirty metres and look at the silhouette. Vase, column, spreading dome, drooping lower branches — form is a real character and it is free.
- Scratch a twig and smell it if you are still choosing between two candidates.
Done in that order it takes about ninety seconds and resolves most temperate trees. Done in the reverse order — starting with a close-up photograph of bark — it frequently resolves nothing at all, which is why so many winter identification attempts fail.
What the observation record shows
Every entry in this key that carries a scientific name is matched against GBIF, the international register of biodiversity records, and against iNaturalist. That puts a hard number behind 34 of the 34trees here: 5,266,559 georeferenced records across the 34 entries that resolve to a single species, spanning 18 families, the oldest of them collected in 1995. The snapshot was taken on 2026-09-04.
That evidence is not spread evenly, and it is worth knowing before you trust a narrow result. The five best-recorded trees in this key hold 67% of all the records between them: American sycamore maple and Norway maple alone accounts for 1,327,995, while River birch has 9,412. A common thing is common in the data too, so when a filter narrows to one frequent entry and one rare one, the frequent one is usually the answer — and the record count is the quickest way to see which is which. The same skew applies geographically: 28% of these records come from the United States, so the key describes what is reported there far better than it describes anywhere else.
When these are actually reported
Half of every record for this group falls in April–July. A raw month count measures two things at once — when the organism is about, and when people are outdoors with a camera — and the second effect is large enough to give almost anything a summer peak. The line on the figure divides each month by the baseline for every species in every Orvik key, which answers a different question: relative to when people record anything at all, when are these trees recorded? Values above 1.0 are the months that belong to this group rather than to the season. On that measure 25 of the 34trees here peak outside the warm half of the year — Northern red oak, Douglas fir, Honey locust among them. Those are the ones a seasonal rule of thumb gets wrong.
Records behind each entry
Sorted by how much evidence exists, not by how likely you are to meet one. The peak month is the effort-adjusted figure, and it is left blank wherever the sample is too thin for the month-to-month wobble to mean anything.
| Entry | Accepted name | Rank | GBIF records | Research-grade | Half fall in | Peak, adjusted | Most reported from |
|---|---|---|---|---|---|---|---|
| American sycamore maple and Norway maple | Acer pseudoplatanus L. | species | 1,327,995 | 90,488 | Apr–Jul | June | the United Kingdom |
| Scots pine | Pinus sylvestris L. | species | 1,187,370 | 120,788 | Apr–Jul | July | Sweden |
| Black locust | Robinia pseudoacacia L. | species | 496,561 | 137,923 | Apr–Jul | May | France |
| Black cherry | Prunus serotina Ehrh. | species | 288,858 | 135,083 | Apr–Jul | May | the Netherlands |
| Northern red oak | Quercus rubra L. | species | 226,793 | 123,423 | May–Aug | November | the United States |
| Douglas fir | Pseudotsuga menziesii (Mirb.) Franco | species | 164,367 | 89,698 | Mar–Jul | February | the United States |
| Honey locust | Gleditsia triacanthos L. | species | 139,443 | 77,965 | Mar–Jul | February | the United States |
| Red maple | Acer rubrum L. | species | 133,130 | 162,550 | Mar–Jul | October | the United States |
| Eastern white pine | Pinus strobus L. | species | 115,039 | 140,642 | Mar–Jul | February | the United States |
| Sweetgum | Liquidambar styraciflua L. | species | 97,409 | 116,114 | Mar–Jul | December | the United States |
| Silver maple | Acer saccharinum L. | species | 95,335 | 63,212 | May–Aug | October | the United States |
| American beech | Fagus grandifolia Ehrh. | species | 90,676 | 123,876 | Mar–Jul | February | the United States |
| Tulip tree | Liriodendron tulipifera L. | species | 77,205 | 105,618 | Apr–Jun | April | the United States |
| Eastern redcedar | Juniperus virginiana L. | species | 71,990 | 122,953 | Jan–Jun | February | the United States |
| Ponderosa pine | Pinus ponderosa Douglas ex C.Lawson | species | 67,650 | 39,339 | Apr–Jul | December | the United States |
| Eastern hemlock | Tsuga canadensis (L.) Carrière | species | 64,784 | 82,747 | Mar–Jul | February | the United States |
| Sassafras | Sassafras albidum (Nutt.) Nees | species | 62,820 | 75,951 | Apr–Jul | April | the United States |
| Quaking aspen | Populus tremuloides Michx. | species | 61,907 | 80,099 | Jun–Aug | June | the United States |
| Sugar maple | Acer saccharum Marshall | species | 59,528 | 116,271 | May–Aug | October | the United States |
| Sycamore and London plane | Platanus occidentalis L. | species | 50,035 | 96,662 | Feb–Jul | November | the United States |
| White oak | Quercus alba L. | species | 47,555 | 83,064 | Apr–Aug | December | the United States |
| American elm | Ulmus americana L. | species | 45,426 | 78,701 | Mar–Jul | November | the United States |
| Cottonwood | Populus deltoides W.Bartram ex Marshall | species | 36,424 | 64,817 | Apr–Jul | April | the United States |
| Striped maple | Acer pensylvanicum L. | species | 33,473 | 43,412 | May–Jul | May | the United States |
| Persimmon | Diospyros virginiana L. | species | 32,442 | 50,429 | May–Aug | October | the United States |
| Paper birch | Betula papyrifera Marshall | species | 28,894 | 51,283 | Mar–Jul | February | Canada |
| Osage orange | Maclura pomifera (Raf. ex Sarg.) C.K.Schneid. | species | 28,756 | 36,925 | Jul–Oct | November | the United States |
| Hackberry | Celtis occidentalis L. | species | 28,574 | 47,957 | May–Aug | October | the United States |
| Coast redwood and giant sequoia | Sequoia sempervirens (D.Don) Endl. | species | 25,128 | 41,597 | Jan–Jun | February | the United States |
| Ironwood and musclewood | Carpinus caroliniana Walter | species | 22,618 | 39,459 | Apr–Jul | March | the United States |
| Shagbark hickory | Carya ovata (Mill.) K.Koch | species | 17,910 | 41,288 | Mar–Jul | February | the United States |
| White ash | Fraxinus americana L. | species | 17,819 | 66,604 | May–Aug | October | the United States |
| Black oak | Quercus velutina Lam. | species | 13,233 | 34,173 | Jun–Sep | October | the United States |
| River birch | Betula nigra L. | species | 9,412 | 31,775 | Mar–Jul | December | the United States |
This table is assembled from open data and is free to reuse with a link back to this page. The snapshot behind every Orvik key is published as one downloadable file on the open field data page, with each source's licence terms.
Questions people ask about this
Can you really identify a tree from bark alone?
For some species, easily: shagbark hickory, hackberry, beech, sycamore, paper birch, ponderosa pine and persimmon are all decided by bark in one look. For many others bark narrows the field to a genus and no further, because hickories, willows, hawthorns and the white oak group overlap heavily. Combine bark with buds, fruit on the ground and the tree's silhouette and most temperate trees resolve.
Why does the bark look different on the branches than on the trunk?
Branch bark stays juvenile far longer than trunk bark. Scots pine is the classic demonstration: the upper trunk and limbs are orange and papery while the base is dark and blocky, on the same tree. Always read bark on the main trunk at about chest height, and on the largest example of the tree you can find.
What tree has white peeling bark?
Paper birch, which peels in horizontal papery sheets and is orange underneath. Grey birch is whiter still but does not peel and has black triangular patches below each branch. Quaking aspen is smooth greenish-white with a chalky bloom that rubs off, and it does not peel at all. Sycamore is white on the upper trunk but flakes in irregular camouflage plates rather than sheets.
What tree has thorns growing out of the trunk?
Honey locust, and in North America essentially nothing else. Wild honey locusts carry clusters of branched red-brown thorns up to 20 cm long directly on the trunk. Black locust and Osage orange have thorns too, but only at the nodes on twigs rather than on the bark of the trunk itself.
What is the tree with warty bumps all over the bark?
Hackberry. Pale grey bark covered in irregular corky warts and knobbly ridges is unique to it among common eastern trees, which makes it one of the easiest winter identifications available. Sweetgum produces corky wings on its twigs, but the trunk is deeply furrowed rather than warty.
Does moss on a tree tell you which way is north?
Weakly, and not reliably enough to navigate by. In the northern hemisphere the shaded north side of a trunk stays damper and does grow more moss and lichen on average, but local shade, prevailing wind and rain direction override it constantly. It matters more for identification: moss and lichen cover changes how bark texture reads, so brush a patch clear before judging the surface.
Is it safe to scratch bark to identify a tree?
Scratch a twig or a small branch, never the main trunk. A shallow nick on a twig heals; a ring of damage on a trunk can girdle a tree and kill it, and repeated knife cuts are an infection route. The scratch-and-smell test is genuinely useful for sassafras, black cherry, redcedar and walnut, and a twig gives you all of it.
Still not sure? Point a camera at it
A filter narrows trees down to a shortlist. Orvik reads the photo itself and names the species, with the look-alikes ranked underneath so you can check the call yourself.