We currently have a total of 195 comparison guides, with 127 completed and published, and 68 incomplete guides under construction.
| Guide | Date Started↓ | Date Updated |
| Tall Goldenrod (Solidago altissima) vs. Giant Goldenrod (Solidago gigantea) | Dec 04, 2024 | Dec 05, 2024 |
| Partridge Pea (Chamaecrista fasciculata) vs. Persian Silktree (Albizia julibrissin) | Sep 16, 2024 | Sep 16, 2024 |
| Orchard Grass (Dactylis glomerata) vs. Common Velvetgrass (Holcus lanatus) | Jun 28, 2024 | Jun 29, 2024 |
| Rhomboid Mercury (Acalypha rhomboidea) vs. Deam's Mercury (Acalypha deamii) | Jun 21, 2024 | Jun 25, 2024 |
| Common Milkweed (Asclepias syriaca) vs. Hemp Dogbane (Apocynum cannabinum) | Jun 19, 2024 | Jun 19, 2024 |
| Spreading Dogbane (Apocynum androsaemifolium) vs. Hemp Dogbane (Apocynum cannabinum) | Jun 17, 2024 | Jun 19, 2024 |
| Dwarf St. John's Wort (Hypericum mutilum) vs. Northern St. John's Wort (Hypericum boreale) | May 23, 2024 | May 24, 2024 |
| Northern Blue Flag (Iris versicolor) vs. Southern Blue Flag (Iris virginica) | May 06, 2024 | Jun 26, 2024 |
| Narrow-leaved Spring Beauty (Claytonia virginica) vs. Northern Spring Beauty (Claytonia caroliniana) | Apr 07, 2024 | Apr 07, 2024 |
| Japanese Clover (Kummerowia striata) vs. Korean Clover (Kummerowia stipulacea) | Sep 11, 2023 | Sep 11, 2023 |
| Yellow Nutsedge (Cyperus esculentus) vs. Straw-Colored Flatsedge (Cyperus strigosus) | Aug 30, 2023 | Aug 30, 2023 |
| Eastern Bottlebrush Grass (Elymus hystrix) vs. Silky Wild Rye (Elymus villosus) | Jul 23, 2023 | Nov 02, 2023 |
| Canadian Clearweed (Pilea pumila) vs. Black-fruited Clearweed (Pilea fontana) | Jul 21, 2023 | Aug 10, 2023 |
| Robin's Plantain (Erigeron pulchellus) vs. Oakleaf Fleabane (Erigeron quercifolius) | May 15, 2023 | May 25, 2023 |
| Philadelphia Fleabane (Erigeron philadelphicus) vs. Oakleaf Fleabane (Erigeron quercifolius) | May 10, 2023 | May 11, 2023 |
| Prairie Fleabane (Erigeron strigosus) vs. Philadelphia Fleabane (Erigeron philadelphicus) | May 09, 2023 | May 28, 2023 |
| Whitegrass (Leersia virginica) vs. Japanese Stiltgrass (Microstegium vimineum) | Apr 10, 2023 | Jun 28, 2024 |
| Field Thistle (Cirsium discolor) vs. Bull Thistle (Cirsium vulgare) | Mar 08, 2023 | Mar 08, 2023 |
| Virginia Creeper (Parthenocissus quinquefolia) vs. Five-Fingered Aralia (Eleutherococcus sieboldianus) | Feb 24, 2023 | Feb 24, 2023 |
| Norway Spruce (Picea abies) vs. Caucasian Spruce (Picea orientalis) | Jan 16, 2023 | Jan 16, 2023 |
| Loblolly Pine (Pinus taeda) vs. Slash Pine (Pinus elliottii) | Jan 08, 2023 | Jan 24, 2023 |
| Shortleaf Pine (Pinus echinata) vs. Eastern White Pine (Pinus strobus) | Jan 04, 2023 | Jan 05, 2023 |
| Pitch Pine (Pinus rigida) vs. Loblolly Pine (Pinus taeda) | Jan 03, 2023 | Feb 04, 2023 |
| Shortleaf Pine (Pinus echinata) vs. Loblolly Pine (Pinus taeda) | Jan 02, 2023 | Jan 07, 2023 |
| Loblolly Pine (Pinus taeda) vs. Eastern White Pine (Pinus strobus) | Jan 02, 2023 | Jan 08, 2023 |
| Early Wildrye (Elymus macgregorii) vs. Riverbank Wildrye (Elymus riparius) | Dec 31, 2022 | Dec 31, 2022 |
| Canada Wildrye (Elymus canadensis) vs. Southeastern Wildrye (Elymus glabriflorus) | Dec 28, 2022 | Jan 30, 2023 |
| Canada Wildrye (Elymus canadensis) vs. Riverbank Wildrye (Elymus riparius) | Dec 15, 2022 | Feb 13, 2023 |
| Early Wildrye (Elymus macgregorii) vs. Southeastern Wildrye (Elymus glabriflorus) | Dec 08, 2022 | Dec 27, 2022 |
| Wingstem (Verbesina alternifolia) vs. Yellow Crownbeard (Verbesina occidentalis) | Nov 30, 2022 | Nov 30, 2022 |
| Riverbank Wildrye (Elymus riparius) vs. Silky Wild Rye (Elymus villosus) | Nov 26, 2022 | Jun 16, 2023 |
| Purpletop (Tridens flavus) vs. Johnsongrass (Sorghum halepense) | Nov 13, 2022 | Nov 16, 2022 |
| Rhomboid Mercury (Acalypha rhomboidea) vs. Asian Copperleaf (Acalypha australis) | Jul 08, 2022 | Feb 02, 2023 |
| Tall Blue Lettuce (Lactuca biennis) vs. Woodland Lettuce (Lactuca floridana) | Jul 06, 2022 | Apr 16, 2023 |
| White Avens (Geum canadense) vs. Spring Avens (Geum vernum) | Jun 18, 2022 | Jun 19, 2023 |
| Prairie Fleabane (Erigeron strigosus) vs. Annual Fleabane (Erigeron annuus) | Jun 17, 2022 | Mar 14, 2024 |
| Philadelphia Fleabane (Erigeron philadelphicus) vs. Robin's Plantain (Erigeron pulchellus) | Jun 17, 2022 | May 16, 2023 |
| Annual Fleabane (Erigeron annuus) vs. Philadelphia Fleabane (Erigeron philadelphicus) | Jun 17, 2022 | May 05, 2023 |
| Clustered Blacksnakeroot (Sanicula odorata) vs. Small's Blacksnakeroot (Sanicula smallii) | May 31, 2022 | May 31, 2022 |
| Canadian Blacksnakeroot (Sanicula canadensis) vs. Small's Blacksnakeroot (Sanicula smallii) | May 08, 2022 | May 31, 2022 |
| Maryland Sanicle (Sanicula marilandica) vs. Clustered Blacksnakeroot (Sanicula odorata) | May 06, 2022 | May 31, 2022 |
| Canadian Blacksnakeroot (Sanicula canadensis) vs. Largefruit Blacksnakeroot (Sanicula trifoliata) | May 06, 2022 | May 06, 2022 |
| Canadian Blacksnakeroot (Sanicula canadensis) vs. Clustered Blacksnakeroot (Sanicula odorata) | May 06, 2022 | May 09, 2022 |
| Canadian Blacksnakeroot (Sanicula canadensis) vs. Maryland Sanicle (Sanicula marilandica) | May 06, 2022 | May 06, 2022 |
| Late Boneset (Eupatorium serotinum) vs. Tall Thoroughwort (Eupatorium altissimum) | Nov 06, 2021 | Aug 17, 2022 |
| Butterfly Milkweed (Asclepias tuberosa) vs. Tropical Milkweed (Asclepias curassavica) | Oct 05, 2021 | Oct 05, 2021 |
| Common Milkweed (Asclepias syriaca) vs. Purple Milkweed (Asclepias purpurascens) | Oct 04, 2021 | Oct 05, 2021 |
| Common Milkweed (Asclepias syriaca) vs. Poke Milkweed (Asclepias exaltata) | Sep 22, 2021 | Aug 29, 2024 |
| Partridge Pea (Chamaecrista fasciculata) vs. Sensitive Partridge Pea (Chamaecrista nictitans) | Sep 20, 2021 | Sep 30, 2021 |
| Golden Alexanders (Zizia aurea) vs. Meadow Parsnip (Thaspium trifoliatum) | May 06, 2021 | May 22, 2024 |
| Shortleaf Pine (Pinus echinata) vs. Virginia Pine (Pinus virginiana) | Jan 27, 2021 | Jan 02, 2023 |
| American Holly (Ilex opaca) vs. European Holly (Ilex aquifolium) | Jan 19, 2021 | Jan 26, 2021 |
| Water Oak (Quercus nigra) vs. Willow Oak (Quercus phellos) | Jan 11, 2021 | Aug 25, 2022 |
| Swamp Chestnut Oak (Quercus michauxii) vs. Chinquapin Oak (Quercus muehlenbergii) | Jan 06, 2021 | Jan 06, 2021 |
| Swamp Chestnut Oak (Quercus michauxii) vs. Chestnut Oak (Quercus montana) | Dec 21, 2020 | Dec 22, 2020 |
| Chestnut Oak (Quercus montana) vs. Chinquapin Oak (Quercus muehlenbergii) | Dec 21, 2020 | Jan 05, 2021 |
| Lemon Balm (Melissa officinalis) vs. Catnip (Nepeta cataria) | Dec 17, 2020 | Dec 17, 2020 |
| Bear Oak (Quercus ilicifolia) vs. Blackjack Oak (Quercus marilandica) | Oct 20, 2020 | Oct 20, 2020 |
| Redstar (Ipomoea coccinea) vs. Scarlet Creeper (Ipomoea hederifolia) | Oct 14, 2020 | Oct 16, 2020 |
| Bear Oak (Quercus ilicifolia) vs. Black Oak (Quercus velutina) | Oct 01, 2020 | Oct 01, 2020 |
| Blackjack Oak (Quercus marilandica) vs. Water Oak (Quercus nigra) | Oct 01, 2020 | Oct 01, 2020 |
| Coastal Plain Joe Pye Weed (Eutrochium dubium) vs. Sweetscented Joe Pye Weed (Eutrochium purpureum) | Sep 21, 2020 | Jun 16, 2022 |
| Hollow Joe Pye Weed (Eutrochium fistulosum) vs. Sweetscented Joe Pye Weed (Eutrochium purpureum) | Sep 21, 2020 | Sep 11, 2024 |
| Sweetscented Joe Pye Weed (Eutrochium purpureum) vs. Spotted Joe Pye Weed (Eutrochium maculatum) | Sep 21, 2020 | Apr 23, 2021 |
| Coastal Plain Joe Pye Weed (Eutrochium dubium) vs. Hollow Joe Pye Weed (Eutrochium fistulosum) | Sep 19, 2020 | Sep 02, 2024 |
| Hollow Joe Pye Weed (Eutrochium fistulosum) vs. Spotted Joe Pye Weed (Eutrochium maculatum) | Sep 19, 2020 | Sep 25, 2020 |
| Coastal Plain Joe Pye Weed (Eutrochium dubium) vs. Spotted Joe Pye Weed (Eutrochium maculatum) | Sep 19, 2020 | Sep 21, 2020 |
| Common Hop (Humulus lupulus) vs. Japanese Hop (Humulus japonicus) | Sep 16, 2020 | Sep 16, 2020 |
| Atlantic White Cedar (Chamaecyparis thyoides) vs. Northern White-Cedar (Thuja occidentalis) | Sep 01, 2020 | Feb 20, 2024 |
| Atlantic White Cedar (Chamaecyparis thyoides) vs. Eastern Redcedar (Juniperus virginiana) | Sep 01, 2020 | Feb 20, 2024 |
| Eastern Redcedar (Juniperus virginiana) vs. Northern White-Cedar (Thuja occidentalis) | Sep 01, 2020 | Sep 01, 2020 |
| White Oak (Quercus alba) vs. Swamp White Oak (Quercus bicolor) | Aug 31, 2020 | Aug 31, 2020 |
| American Sycamore (Platanus occidentalis) vs. London Planetree (Platanus ×hispanica) | Jul 24, 2020 | Jul 24, 2020 |
| Swamp White Oak (Quercus bicolor) vs. Bur Oak (Quercus macrocarpa) | Jul 01, 2020 | Mar 03, 2022 |
| Smooth Sumac (Rhus glabra) vs. Staghorn Sumac (Rhus typhina) | Jun 28, 2020 | Sep 23, 2021 |
| Northern Red Oak (Quercus rubra) vs. Hill's Oak (Quercus ellipsoidalis) | Mar 04, 2020 | Feb 15, 2021 |
| Tall Blue Lettuce (Lactuca biennis) vs. Canada Lettuce (Lactuca canadensis) | Mar 02, 2020 | Jun 10, 2024 |
| American Bittersweet (Celastrus scandens) vs. Oriental Bittersweet (Celastrus orbiculatus) | Feb 25, 2020 | Jul 25, 2020 |
| Paper Birch (Betula papyrifera) vs. European White Birch (Betula pendula) | Feb 16, 2020 | Jul 28, 2020 |
| Gray Birch (Betula populifolia) vs. European White Birch (Betula pendula) | Feb 16, 2020 | Jul 25, 2020 |
| Paper Birch (Betula papyrifera) vs. Mountain Paper Birch (Betula cordifolia) | Feb 11, 2020 | Jul 24, 2020 |
| Gray Birch (Betula populifolia) vs. Paper Birch (Betula papyrifera) | Feb 02, 2020 | Dec 15, 2021 |
| Sweetbay Magnolia (Magnolia virginiana) vs. Southern Magnolia (Magnolia grandiflora) | Jan 16, 2020 | Jan 16, 2020 |
| White Spruce (Picea glauca) vs. Balsam Fir (Abies balsamea) | Dec 29, 2019 | Dec 29, 2019 |
| White Spruce (Picea glauca) vs. Norway Spruce (Picea abies) | Dec 17, 2019 | Jul 24, 2020 |
| Red Maple (Acer rubrum) vs. Sycamore Maple (Acer pseudoplatanus) | Dec 05, 2019 | Apr 28, 2021 |
| Norway Maple (Acer platanoides) vs. Sycamore Maple (Acer pseudoplatanus) | Dec 05, 2019 | Jul 23, 2020 |
| Sugar Maple (Acer saccharum) vs. Black Maple (Acer nigrum) | Dec 05, 2019 | Dec 06, 2019 |
| Balsam Fir (Abies balsamea) vs. Black Spruce (Picea mariana) | Dec 03, 2019 | Nov 01, 2021 |
| Eastern White Pine (Pinus strobus) vs. Red Pine (Pinus resinosa) | Dec 01, 2019 | Dec 17, 2021 |
| Eastern Hemlock (Tsuga canadensis) vs. Norway Spruce (Picea abies) | Dec 01, 2019 | Dec 29, 2019 |
| Eastern Hemlock (Tsuga canadensis) vs. Balsam Fir (Abies balsamea) | Dec 01, 2019 | Jul 28, 2020 |
| White Spruce (Picea glauca) vs. Red Spruce (Picea rubens) | Dec 01, 2019 | Dec 29, 2019 |
| White Ash (Fraxinus americana) vs. Black Ash (Fraxinus nigra) | Nov 24, 2019 | Nov 24, 2019 |
| Black Ash (Fraxinus nigra) vs. Green Ash (Fraxinus pennsylvanica) | Nov 24, 2019 | Mar 24, 2021 |
| White Ash (Fraxinus americana) vs. Green Ash (Fraxinus pennsylvanica) | Nov 22, 2019 | Jun 23, 2020 |
| Red Spruce (Picea rubens) vs. Norway Spruce (Picea abies) | Nov 20, 2019 | Dec 29, 2019 |
| White Spruce (Picea glauca) vs. Black Spruce (Picea mariana) | Nov 19, 2019 | Feb 27, 2022 |
| Sweet Birch (Betula lenta) vs. Yellow Birch (Betula alleghaniensis) | Nov 10, 2019 | Nov 11, 2019 |
| Red Mulberry (Morus rubra) vs. White Mulberry (Morus alba) | Nov 07, 2019 | Apr 22, 2023 |
| Northern Red Oak (Quercus rubra) vs. Pin Oak (Quercus palustris) | Nov 06, 2019 | Jul 30, 2020 |
| Scarlet Oak (Quercus coccinea) vs. Black Oak (Quercus velutina) | Nov 06, 2019 | Mar 31, 2023 |
| Northern Red Oak (Quercus rubra) vs. Scarlet Oak (Quercus coccinea) | Nov 06, 2019 | Nov 06, 2019 |
| Pin Oak (Quercus palustris) vs. Scarlet Oak (Quercus coccinea) | Nov 06, 2019 | Oct 18, 2022 |
| Pitch Pine (Pinus rigida) vs. Eastern White Pine (Pinus strobus) | Nov 01, 2019 | Nov 01, 2019 |
| Red Pine (Pinus resinosa) vs. Scots Pine (Pinus sylvestris) | Nov 01, 2019 | Dec 20, 2021 |
| Greater Celandine (Chelidonium majus) vs. Celandine Poppy (Stylophorum diphyllum) | Oct 31, 2019 | May 24, 2021 |
| Eastern Black Walnut (Juglans nigra) vs. Tree of Heaven (Ailanthus altissima) | Oct 31, 2019 | Oct 31, 2019 |
| Eastern Black Walnut (Juglans nigra) vs. Butternut (Juglans cinerea) | Oct 31, 2019 | Jul 28, 2020 |
| Tree of Heaven (Ailanthus altissima) vs. Staghorn Sumac (Rhus typhina) | Oct 31, 2019 | Sep 23, 2021 |
| Flowering Dogwood (Cornus florida) vs. Kousa Dogwood (Cornus kousa) | Oct 30, 2019 | Apr 20, 2020 |
| Red Maple (Acer rubrum) vs. Silver Maple (Acer saccharinum) | Oct 23, 2019 | Dec 29, 2019 |
| Silver Maple (Acer saccharinum) vs. Sugar Maple (Acer saccharum) | Oct 23, 2019 | Oct 23, 2019 |
| Red Maple (Acer rubrum) vs. Mountain Maple (Acer spicatum) | Oct 23, 2019 | Dec 04, 2019 |
| Norway Maple (Acer platanoides) vs. Red Maple (Acer rubrum) | Oct 23, 2019 | Oct 25, 2019 |
| American Sweetgum (Liquidambar styraciflua) vs. Castor-Aralia (Kalopanax septemlobus) | Oct 22, 2019 | Nov 06, 2023 |
| White Oak (Quercus alba) vs. Bur Oak (Quercus macrocarpa) | Oct 20, 2019 | Jul 24, 2020 |
| Pale Touch-Me-Not (Impatiens pallida) vs. Jewelweed (Impatiens capensis) | Oct 20, 2019 | Aug 17, 2023 |
| American Beech (Fagus grandifolia) vs. European Beech (Fagus sylvatica) | Oct 20, 2019 | Oct 29, 2019 |
| Eastern Poison Ivy (Toxicodendron radicans) vs. Japanese Creeper (Parthenocissus tricuspidata) | Oct 19, 2019 | Dec 29, 2019 |
| Box Elder (Acer negundo) vs. Eastern Poison Ivy (Toxicodendron radicans) | Oct 19, 2019 | Oct 21, 2019 |
| Eastern Poison Ivy (Toxicodendron radicans) vs. Fragrant Sumac (Rhus aromatica) | Oct 19, 2019 | Oct 29, 2019 |
| Northern Red Oak (Quercus rubra) vs. Black Oak (Quercus velutina) | Oct 18, 2019 | Oct 13, 2024 |
| White Snakeroot (Ageratina altissima) vs. Late Boneset (Eupatorium serotinum) | Oct 18, 2019 | Oct 13, 2024 |
| Norway Maple (Acer platanoides) vs. Sugar Maple (Acer saccharum) | Oct 17, 2019 | Jan 20, 2021 |
| Rhomboid Mercury (Acalypha rhomboidea) vs. Virginia Threeseed Mercury (Acalypha virginica) | Oct 16, 2019 | Jul 11, 2022 |
| Red Maple (Acer rubrum) vs. Sugar Maple (Acer saccharum) | Oct 15, 2019 | Oct 23, 2019 |
These guides are incomplete and under construction, and are more likely to have errors in them. Use them at your own risk; when in doubt double-check other sources before relying on them for definitive ID.
| Guide | Date Started↓ | Date Updated |
| Balsam Fir (Abies balsamea) vs. Fraser Fir (Abies fraseri) | Dec 18, 2024 | Dec 18, 2024 |
| American Burnweed (Erechtites hieraciifolius) vs. Common Groundsel (Senecio vulgaris) | Aug 05, 2024 | Aug 05, 2024 |
| Tall Oatgrass (Arrhenatherum elatius) vs. Tall Fescue (Lolium arundinaceum) | May 29, 2024 | May 29, 2024 |
| Bishop's Goutweed (Aegopodium podagraria) vs. Golden Alexanders (Zizia aurea) | May 22, 2024 | May 23, 2024 |
| Blue Sedge (Carex glaucodea) vs. Thinfruit Sedge (Carex flaccosperma) | May 01, 2024 | May 01, 2024 |
| Blue Sedge (Carex glaucodea) vs. Tarheel Sedge (Carex pigra) | May 01, 2024 | May 01, 2024 |
| Tall Goldenrod (Solidago altissima) vs. Canada Goldenrod (Solidago canadensis) | Jul 20, 2023 | Dec 20, 2024 |
| Prairie Fleabane (Erigeron strigosus) vs. Oakleaf Fleabane (Erigeron quercifolius) | May 21, 2023 | May 21, 2023 |
| Prickly Lettuce (Lactuca serriola) vs. Canada Lettuce (Lactuca canadensis) | Apr 16, 2023 | Aug 29, 2024 |
| Honeylocust (Gleditsia triacanthos) vs. Black Locust (Robinia pseudoacacia) | Mar 31, 2023 | Mar 31, 2023 |
| Black Locust (Robinia pseudoacacia) vs. Bristly Locust (Robinia hispida) | Mar 30, 2023 | Mar 30, 2023 |
| Pond Pine (Pinus serotina) vs. Loblolly Pine (Pinus taeda) | Feb 03, 2023 | Feb 03, 2023 |
| Virginia Pine (Pinus virginiana) vs. Jack Pine (Pinus banksiana) | Jan 02, 2023 | Jan 02, 2023 |
| Scarlet Oak (Quercus coccinea) vs. Shumard Oak (Quercus shumardii) | Dec 27, 2022 | Dec 27, 2022 |
| Canada Wildrye (Elymus canadensis) vs. Silky Wild Rye (Elymus villosus) | Dec 13, 2022 | Dec 13, 2022 |
| Virginia Wildrye (Elymus virginicus) vs. Southeastern Wildrye (Elymus glabriflorus) | Dec 08, 2022 | Dec 18, 2022 |
| Early Wildrye (Elymus macgregorii) vs. Virginia Wildrye (Elymus virginicus) | Nov 28, 2022 | Dec 22, 2022 |
| Canada Wildrye (Elymus canadensis) vs. Virginia Wildrye (Elymus virginicus) | Nov 26, 2022 | Nov 26, 2022 |
| Swamp Tupelo (Nyssa biflora) vs. Black Tupelo (Nyssa sylvatica) | Nov 21, 2022 | Nov 21, 2022 |
| Broomsedge Bluestem (Andropogon virginicus) vs. Little Bluestem (Schizachyrium scoparium) | Nov 04, 2022 | Nov 04, 2022 |
| Longleaf Pine (Pinus palustris) vs. Slash Pine (Pinus elliottii) | Oct 31, 2022 | Oct 31, 2022 |
| Rhomboid Mercury (Acalypha rhomboidea) vs. Slender Threeseed Mercury (Acalypha gracilens) | Jul 11, 2022 | Jul 11, 2022 |
| Virginia Threeseed Mercury (Acalypha virginica) vs. Slender Threeseed Mercury (Acalypha gracilens) | Jul 11, 2022 | Jul 13, 2023 |
| Sweetscented Joe Pye Weed (Eutrochium purpureum) vs. Appalachian Joe-Pye Weed (Eutrochium steelei) | Jul 05, 2022 | Jan 01, 2023 |
| Early Meadow-Rue (Thalictrum dioicum) vs. King of the Meadow (Thalictrum pubescens) | Jul 02, 2022 | Jul 02, 2022 |
| King of the Meadow (Thalictrum pubescens) vs. Waxyleaf Meadow-Rue (Thalictrum revolutum) | Jul 02, 2022 | Jul 02, 2022 |
| White Avens (Geum canadense) vs. Cream Avens (Geum virginianum) | Jul 01, 2022 | Jul 01, 2022 |
| White Avens (Geum canadense) vs. Rough Avens (Geum laciniatum) | Jun 18, 2022 | Jun 18, 2022 |
| Honewort (Cryptotaenia canadensis) vs. Japanese Honewort (Cryptotaenia japonica) | May 06, 2022 | May 06, 2022 |
| Austrian Pine (Pinus nigra) vs. Red Pine (Pinus resinosa) | Dec 22, 2021 | Dec 22, 2021 |
| Smooth Blue Aster (Symphyotrichum laeve) vs. Purplestem aster (Symphyotrichum puniceum) | Nov 30, 2021 | Nov 30, 2021 |
| Small-Flowered Buttercup (Ranunculus abortivus) vs. Allegheny Mountain buttercup (Ranunculus allegheniensis) | May 27, 2021 | May 27, 2021 |
| Small-Flowered Buttercup (Ranunculus abortivus) vs. Rock Buttercup (Ranunculus micranthus) | May 27, 2021 | May 27, 2021 |
| Wild Parsnip (Pastinaca sativa) vs. Golden Alexanders (Zizia aurea) | May 05, 2021 | May 05, 2021 |
| Heart-Leaf Golden Alexander (Zizia aptera) vs. Golden Alexanders (Zizia aurea) | May 05, 2021 | May 05, 2021 |
| Common Star of Bethlehem (Ornithogalum umbellatum) vs. Drooping Star of Bethlehem (Ornithogalum nutans) | Apr 19, 2021 | Apr 19, 2021 |
| Scarlet Oak (Quercus coccinea) vs. Hill's Oak (Quercus ellipsoidalis) | Feb 15, 2021 | Feb 15, 2021 |
| Laurel Oak (Quercus laurifolia) vs. Sand Laurel Oak (Quercus hemisphaerica) | Feb 05, 2021 | Feb 05, 2021 |
| Virginia Pine (Pinus virginiana) vs. Table Mountain Pine (Pinus pungens) | Jan 28, 2021 | Jan 28, 2021 |
| American Basswood (Tilia americana) vs. Littleleaf Linden (Tilia cordata) | Jan 25, 2021 | Jan 25, 2021 |
| English Ivy (Hedera helix) vs. Atlantic Ivy (Hedera hibernica) | Jan 22, 2021 | Jan 22, 2021 |
| European Holly (Ilex aquifolium) vs. Chinese Holly (Ilex cornuta) | Jan 20, 2021 | Jan 23, 2021 |
| Chinquapin Oak (Quercus muehlenbergii) vs. Dwarf Chinquapin Oak (Quercus prinoides) | Jan 06, 2021 | Jan 06, 2021 |
| Northern Red Oak (Quercus rubra) vs. Shumard Oak (Quercus shumardii) | Oct 05, 2020 | Oct 05, 2020 |
| Southern Red Oak (Quercus falcata) vs. Cherrybark Oak (Quercus pagoda) | Sep 11, 2020 | Sep 11, 2020 |
| Overcup Oak (Quercus lyrata) vs. Bur Oak (Quercus macrocarpa) | Aug 28, 2020 | Oct 01, 2020 |
| White Snakeroot (Ageratina altissima) vs. Smallspike False Nettle (Boehmeria cylindrica) | Jul 16, 2020 | Jul 16, 2020 |
| Siberian Elm (Ulmus pumila) vs. Chinese Elm (Ulmus parvifolia) | Jun 26, 2020 | Jun 26, 2020 |
| Northern Red Oak (Quercus rubra) vs. Southern Red Oak (Quercus falcata) | Jun 19, 2020 | Aug 23, 2022 |
| Honewort (Cryptotaenia canadensis) vs. Bishop's Goutweed (Aegopodium podagraria) | Jun 12, 2020 | Jun 12, 2020 |
| Sassafras (Sassafras albidum) vs. Northern Spicebush (Lindera benzoin) | Jun 10, 2020 | Jun 10, 2020 |
| Engelmann Spruce (Picea engelmannii) vs. Blue Spruce (Picea pungens) | Apr 13, 2020 | Apr 13, 2020 |
| Pitch Pine (Pinus rigida) vs. Table Mountain Pine (Pinus pungens) | Mar 06, 2020 | Mar 06, 2020 |
| Pin Oak (Quercus palustris) vs. Hill's Oak (Quercus ellipsoidalis) | Mar 06, 2020 | Jul 26, 2023 |
| Gray Birch (Betula populifolia) vs. Yellow Birch (Betula alleghaniensis) | Feb 20, 2020 | Feb 20, 2020 |
| White Oak (Quercus alba) vs. Post Oak (Quercus stellata) | Jan 30, 2020 | Oct 19, 2020 |
| Red Spruce (Picea rubens) vs. Black Spruce (Picea mariana) | Nov 29, 2019 | Nov 29, 2019 |
| White Ash (Fraxinus americana) vs. Blue Ash (Fraxinus quadrangulata) | Nov 22, 2019 | Nov 22, 2019 |
| White Mulberry (Morus alba) vs. Hairy Crabweed (Fatoua villosa) | Nov 14, 2019 | Nov 14, 2019 |
| River Birch (Betula nigra) vs. Yellow Birch (Betula alleghaniensis) | Nov 11, 2019 | Dec 10, 2019 |
| White Snakeroot (Ageratina altissima) vs. Blue Mistflower (Conoclinium coelestinum) | Nov 08, 2019 | Sep 29, 2021 |
| Common Pear (Pyrus communis) vs. Callery Pear (Pyrus calleryana) | Nov 07, 2019 | Jul 15, 2020 |
| Pitch Pine (Pinus rigida) vs. Jack Pine (Pinus banksiana) | Nov 01, 2019 | Jan 04, 2023 |
| Eastern White Pine (Pinus strobus) vs. Jack Pine (Pinus banksiana) | Nov 01, 2019 | Nov 01, 2019 |
| Jack Pine (Pinus banksiana) vs. Scots Pine (Pinus sylvestris) | Nov 01, 2019 | Nov 01, 2019 |
| Blackjack Oak (Quercus marilandica) vs. Black Oak (Quercus velutina) | Oct 28, 2019 | Dec 08, 2020 |
| Southern Red Oak (Quercus falcata) vs. Blackjack Oak (Quercus marilandica) | Oct 28, 2019 | Oct 16, 2020 |
| Striped Maple (Acer pensylvanicum) vs. Mountain Maple (Acer spicatum) | Oct 23, 2019 | Aug 29, 2024 |
