Native plants · Illinois
Native plants of Mercer County
379 plant species are recorded as native to Illinois in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in Mercer County by USDA PLANTS. 169 of them have growing records you can filter by light, moisture, height and estimated cold hardiness. 3 more species are listed as both native and introduced and kept in a separate section.
County summary · USDA PLANTS and Kew WCVP
Mercer County, Illinois
- Native species
- 379 Typical Illinois county: 641 (median of 102 counties)
- Garden-ready natives
- 169 Typical Illinois county: 272
- Share by type (all 379 native species)
-
Percent of the 379 native species in each growth type
Wildflowers make up the largest share of the native list (62%), followed by grasses and grass-like plants (18%).
The native plant list
Garden-ready natives 169
Native species with PLANTS growing records (height, light, moisture, minimum temperature). “—” means PLANTS has no value.
| Plant | Type | Height | Light | Water use | Hardy to |
|---|---|---|---|---|---|
| American basswood Tilia americana | Tree | 100 ft | Shade-tolerant | Medium | Zone 2b |
| American bellflower Campanulastrum americanum | Wildflower (forb) | 6 ft | Shade-tolerant | Medium | Zone 12b |
| American bittersweet Celastrus scandens | Vine | 15 ft | Shade-tolerant | High | Zone 3b |
| American elm Ulmus americana | Tree | 120 ft | Sun–part shade | High | Zone 2b |
| American hazelnut Corylus americana | Shrub | 10 ft | Sun–part shade | Medium | Zone 4a |
| American plum Prunus americana | Tree | 24 ft | Sun | Medium | Zone 3b |
| American pokeweed Phytolacca americana | Wildflower (forb) | 7.3 ft | Shade-tolerant | Medium | Zone 4a |
| American sycamore Platanus occidentalis | Tree | 100 ft | Sun–part shade | High | Zone 4a |
| American water horehound Lycopus americanus | Wildflower (forb) | 1.8 ft | Shade-tolerant | High | Zone 3b |
| American water plantain Alisma subcordatum | Wildflower (forb) | 6 in | Sun | High | Zone 4a |
| Atlantic camas Camassia scilloides | Wildflower (forb) | 2.5 ft | Shade-tolerant | Medium | Zone 4b |
| bearded beggarticks Bidens aristosa | Wildflower (forb) | 3.5 ft | Sun–part shade | High | Zone 12b |
| big bluestem Andropogon gerardii | Grass or grass-like | 6 ft | Sun | Low | Zone 2b |
| bitternut hickory Carya cordiformis | Tree | 75 ft | Sun | Medium | Zone 2b |
| black ash Fraxinus nigra | Tree | 65 ft | Sun | High | Zone 2b |
| black cherry Prunus serotina | Tree | 80 ft | Sun | Medium | Zone 4a |
| black oak Quercus velutina | Tree | 80 ft | Sun–part shade | Medium | Zone 4a |
| black walnut Juglans nigra | Tree | 100 ft | Sun | High | Zone 4b |
| black willow Salix nigra | Tree | 100 ft | Sun | High | Zone 1b |
| blackeyed Susan Rudbeckia hirta | Wildflower (forb) | 1 ft | Sun | Medium | Zone 5a |
| blackjack oak Quercus marilandica | Tree | 25 ft | Sun | Low | Zone 6a |
| blunt broom sedge Carex tribuloides | Grass or grass-like | 3 ft | Shade-tolerant | Medium | Zone 4b |
| bluntleaf bedstraw Galium obtusum | Wildflower (forb) | 1.5 ft | Shade-tolerant | High | Zone 4a |
| boxelder Acer negundo | Tree | 60 ft | Shade-tolerant | Medium | Zone 2b |
| bristly buttercup Ranunculus hispidus | Wildflower (forb) | 2.5 ft | Shade-tolerant | Medium | Zone 4a |
| broadleaf cattail Typha latifolia | Wildflower (forb) | 5 ft | Sun–part shade | High | Zone 3b |
| bur oak Quercus macrocarpa | Tree | 100 ft | Sun–part shade | Medium | Zone 3b |
| Canada germander Teucrium canadense | Wildflower (forb) | 3.3 ft | Sun–part shade | High | Zone 3a |
| Canada goldenrod Solidago canadensis | Wildflower (forb) | 3.5 ft | Sun | Medium | Zone 3a |
| Canada wildrye Elymus canadensis | Grass or grass-like | 3 ft | Shade-tolerant | Medium | Zone 3a |
| Canadian horseweed Conyza canadensis | Wildflower (forb) | 5 ft | Sun | Medium | Zone 12b |
| Canadian milkvetch Astragalus canadensis | Wildflower (forb) | 6 in | Sun | Medium | Zone 3b |
| Canadian waterweed Elodea canadensis | Wildflower (forb) | — | Sun | High | Zone 4a |
| cardinalflower Lobelia cardinalis | Wildflower (forb) | 5.9 ft | Shade-tolerant | Low | Zone 4a |
| Carolina rose Rosa carolina | Shrub | 5 ft | Sun–part shade | Low | Zone 3a |
| cattail sedge Carex typhina | Grass or grass-like | 2 ft | Shade-tolerant | High | Zone 4b |
| chinquapin oak Quercus muehlenbergii | Tree | 70 ft | Sun | Medium | Zone 4a |
| chokecherry Prunus virginiana | Tree | 25 ft | Sun | Medium | Zone 3a |
| common blue violet Viola sororia | Wildflower (forb) | 4 in | Sun–part shade | High | Zone 4b |
| common buttonbush Cephalanthus occidentalis | Tree | 15 ft | Shade-tolerant | High | Zone 4a |
| common duckweed Lemna minor | Wildflower (forb) | — | Sun | High | Zone 3b |
| common evening primrose Oenothera biennis | Wildflower (forb) | 5 ft | Sun | Medium | Zone 4b |
| common hackberry Celtis occidentalis | Tree | 60 ft | Shade-tolerant | Low | Zone 2b |
| common selfheal Prunella vulgaris | Wildflower (forb) | 1.5 ft | Sun–part shade | Medium | Zone 3b |
| common sneezeweed Helenium autumnale | Wildflower (forb) | 4.9 ft | Sun | Medium | Zone 3a |
| composite dropseed Sporobolus compositus | Grass or grass-like | 3 ft | Sun | Low | Zone 3b |
| cup plant Silphium perfoliatum | Wildflower (forb) | 6 ft | Sun–part shade | — | Zone 2b |
| cutleaf coneflower Rudbeckia laciniata | Wildflower (forb) | 8.2 ft | Shade-tolerant | Low | Zone 3b |
| ditch stonecrop Penthorum sedoides | Wildflower (forb) | 2.6 ft | Sun–part shade | Medium | Zone 4b |
| dotted smartweed Polygonum punctatum | Wildflower (forb) | 3.2 ft | Sun | Medium | Zone 10b |
| downy yellow violet Viola pubescens | Wildflower (forb) | 1.3 ft | Shade-tolerant | Medium | Zone 4a |
| eastern cottonwood Populus deltoides | Tree | 190 ft | Sun | High | Zone 3a |
| eastern narrowleaf sedge Carex amphibola | Grass or grass-like | 2 ft | Shade-tolerant | Medium | Zone 7a |
| eastern redbud Cercis canadensis | Tree | 30 ft | Shade-tolerant | Low | Zone 4b |
| eastern redcedar Juniperus virginiana | Tree | 50 ft | Sun–part shade | Low | Zone 3a |
| eastern woodland sedge Carex blanda | Grass or grass-like | 2 ft | Shade-tolerant | High | Zone 4b |
| fall panicgrass Panicum dichotomiflorum | Grass or grass-like | 3.3 ft | Sun | High | Zone 3a |
| field horsetail Equisetum arvense | Fern | 11 in | Sun–part shade | High | Zone 3a |
| fowl mannagrass Glyceria striata | Grass or grass-like | 5.7 ft | Shade-tolerant | Medium | Zone 3b |
| fox sedge Carex vulpinoidea | Grass or grass-like | 3.2 ft | Sun–part shade | Medium | Zone 3b |
| fringeleaf wild petunia Ruellia humilis | Wildflower (forb) | 2.6 ft | Shade-tolerant | Low | Zone 4a |
| frost grape Vitis vulpina | Vine | 83 ft | Sun–part shade | Medium | Zone 5a |
| giant goldenrod Solidago gigantea | Wildflower (forb) | 8.2 ft | Sun–part shade | Medium | Zone 4a |
| gray dogwood Cornus racemosa | Shrub | 10 ft | Shade-tolerant | Medium | Zone 2b |
| gray goldenrod Solidago nemoralis | Wildflower (forb) | 2 ft | Sun | Medium | Zone 4a |
| graybark grape Vitis cinerea | Vine | 50 ft | Sun–part shade | Medium | Zone 6b |
| great St. Johnswort Hypericum ascyron | Wildflower (forb) | 5 ft | Sun | Medium | Zone 5a |
| green ash Fraxinus pennsylvanica | Tree | 80 ft | Shade-tolerant | Medium | Zone 2b |
| green bulrush Scirpus atrovirens | Grass or grass-like | 5.9 ft | Sun | Medium | Zone 2a |
| groundnut Apios americana | Vine | 1 ft | Shade-tolerant | Medium | Zone 5a |
| hairy grama Bouteloua hirsuta | Grass or grass-like | 6 in | Sun | Low | Zone 3b |
| hairy sedge Carex lacustris | Grass or grass-like | 5 ft | Shade-tolerant | High | Zone 4b |
| hairy white oldfield aster Symphyotrichum pilosum | Wildflower (forb) | 3 ft | Shade-tolerant | Medium | Zone 4a |
| halberdleaf rosemallow Hibiscus laevis | Wildflower (forb) | 8 ft | Sun–part shade | High | Zone 6a |
| harvestlice Agrimonia parviflora | Wildflower (forb) | 6 ft | Sun–part shade | High | Zone 4a |
| honeylocust Gleditsia triacanthos | Tree | 70 ft | Sun | Medium | Zone 3b |
| hophornbeam Ostrya virginiana | Tree | 45 ft | Shade-tolerant | Low | Zone 3b |
| Indiangrass Sorghastrum nutans | Grass or grass-like | 6 ft | Sun | Medium | Zone 3b |
| Indianhemp Apocynum cannabinum | Wildflower (forb) | 3.3 ft | Sun–part shade | High | Zone 3a |
| inland rush Juncus interior | Grass or grass-like | 3 ft | Sun–part shade | Medium | Zone 3b |
| Jack in the pulpit Arisaema triphyllum | Wildflower (forb) | 1.5 ft | Shade-tolerant | High | Zone 5b |
| Jerusalem artichoke Helianthus tuberosus | Wildflower (forb) | 9.8 ft | Sun–part shade | Low | Zone 3a |
| Kentucky coffeetree Gymnocladus dioicus | Tree | 100 ft | Sun | Medium | Zone 4a |
| leadplant Amorpha canescens | Shrub | 4 ft | Shade-tolerant | Low | Zone 3b |
| leafy pondweed Potamogeton foliosus | Wildflower (forb) | — | Sun | High | Zone 3b |
| limestone wild petunia Ruellia strepens | Wildflower (forb) | 3.6 ft | Shade-tolerant | Low | Zone 6a |
| little barley Hordeum pusillum | Grass or grass-like | 1.2 ft | Sun | Medium | Zone 10b |
| little bluestem Schizachyrium scoparium | Grass or grass-like | 3 ft | Sun | Low | Zone 3b |
| littleleaf buttercup Ranunculus abortivus | Wildflower (forb) | 2.8 ft | Shade-tolerant | Medium | Zone 3a |
| longleaf pondweed Potamogeton nodosus | Wildflower (forb) | — | Sun | High | Zone 3b |
| Mexican muhly Muhlenbergia mexicana | Grass or grass-like | 3 ft | Sun–part shade | Medium | Zone 4a |
| mockernut hickory Carya tomentosa | Tree | 85 ft | Sun–part shade | Medium | Zone 4a |
| New Jersey tea Ceanothus americanus | Shrub | 3 ft | Shade-tolerant | Low | Zone 4b |
| nodding beggartick Bidens cernua | Wildflower (forb) | 3.2 ft | Sun–part shade | High | Zone 12a |
| nodding fescue Festuca subverticillata | Grass or grass-like | 3 ft | Sun–part shade | Medium | Zone 3a |
| northern maidenhair Adiantum pedatum | Fern | 1.3 ft | Shade-tolerant | Medium | Zone 3b |
| oval-leaf sedge Carex cephalophora | Grass or grass-like | 2.6 ft | Sun–part shade | Low | Zone 4a |
| pale purple coneflower Echinacea pallida | Wildflower (forb) | 1.2 ft | Sun | Medium | Zone 4a |
| panicledleaf ticktrefoil Desmodium paniculatum | Wildflower (forb) | 3 ft | Sun–part shade | Low | Zone 6a |
| partridge pea Chamaecrista fasciculata | Wildflower (forb) | 2.4 ft | Shade-tolerant | Medium | Zone 7a |
| pecan Carya illinoinensis | Tree | 120 ft | Sun | High | Zone 5a |
| Pennsylvania bittercress Cardamine pensylvanica | Wildflower (forb) | 1.5 ft | Shade-tolerant | Medium | Zone 4a |
| Pennsylvania smartweed Polygonum pensylvanicum | Wildflower (forb) | 3.9 ft | Sun | Medium | Zone 10b |
| Philadelphia fleabane Erigeron philadelphicus | Wildflower (forb) | 2.8 ft | Sun–part shade | Medium | Zone 4b |
| pignut hickory Carya glabra | Tree | 80 ft | Sun–part shade | Medium | Zone 4a |
| pin oak Quercus palustris | Tree | 100 ft | Sun | High | Zone 4a |
| pinnate prairie coneflower Ratibida pinnata | Wildflower (forb) | 4 ft | Sun | Medium | Zone 3b |
| porcupinegrass Hesperostipa spartea | Grass or grass-like | 4 ft | Sun | Medium | Zone 3b |
| poverty rush Juncus tenuis | Grass or grass-like | 1.5 ft | Sun–part shade | Medium | Zone 3b |
| prairie cordgrass Spartina pectinata | Grass or grass-like | 8 ft | Sun | High | Zone 3b |
| prairie crab apple Malus ioensis | Tree | 25 ft | Sun | Medium | Zone 4b |
| prairie fleabane Erigeron strigosus | Wildflower (forb) | 3 ft | Sun | Medium | Zone 4b |
| prairie Junegrass Koeleria macrantha | Grass or grass-like | 1.5 ft | Shade-tolerant | High | Zone 3b |
| prairie sandreed Calamovilfa longifolia | Grass or grass-like | 4.5 ft | Sun | Medium | Zone 3b |
| prairie willow Salix humilis | Shrub | 10 ft | Sun–part shade | High | Zone 3a |
| purple lovegrass Eragrostis spectabilis | Grass or grass-like | 11 in | Sun | Low | Zone 3a |
| purple prairie clover Dalea purpurea | Wildflower (forb) | 3 ft | Sun | Medium | Zone 3b |
| purpletop tridens Tridens flavus | Grass or grass-like | 2.5 ft | Sun | Low | Zone 5a |
| quaking aspen Populus tremuloides | Tree | 65 ft | Sun | High | Zone 1a |
| rattlesnake fern Botrychium virginianum | Fern | 1.4 ft | Shade-tolerant | Medium | Zone 3b |
| river birch Betula nigra | Tree | 70 ft | Sun | High | Zone 4a |
| riverbank grape Vitis riparia | Vine | 45 ft | Sun–part shade | Medium | Zone 4a |
| rough avens Geum laciniatum | Wildflower (forb) | 3.1 ft | Sun–part shade | Medium | Zone 5a |
| roughfruit amaranth Amaranthus tuberculatus | Wildflower (forb) | 6.6 ft | Sun | High | Zone 4a |
| roughleaf dogwood Cornus drummondii | Tree | 20 ft | Sun–part shade | Low | Zone 4b |
| roundhead lespedeza Lespedeza capitata | Wildflower (forb) | 2.6 ft | Sun | Low | Zone 4b |
| sago pondweed Stuckenia pectinata | Wildflower (forb) | — | Sun | High | Zone 3b |
| sand dropseed Sporobolus cryptandrus | Grass or grass-like | 3 ft | Sun | Low | Zone 3b |
| sand lovegrass Eragrostis trichodes | Grass or grass-like | 3.5 ft | Sun | Medium | Zone 5a |
| sandbar willow Salix interior | Tree | 30 ft | Sun | — | Zone 1a |
| sawtooth blackberry Rubus argutus | Shrub | 8.2 ft | Sun | Medium | Zone 6a |
| sawtooth sunflower Helianthus grosseserratus | Wildflower (forb) | 5 ft | Sun | Medium | Zone 3a |
| shagbark hickory Carya ovata | Tree | 75 ft | Sun–part shade | Medium | Zone 3a |
| silky dogwood Cornus amomum | Shrub | 10 ft | Sun–part shade | High | Zone 3b |
| silver maple Acer saccharinum | Tree | 90 ft | Sun–part shade | Medium | Zone 2b |
| slender flatsedge Cyperus bipartitus | Grass or grass-like | 5 ft | Sun | Medium | Zone 10b |
| slippery elm Ulmus rubra | Tree | 85 ft | Shade-tolerant | High | Zone 3a |
| smooth hedgenettle Stachys tenuifolia | Wildflower (forb) | 25 ft | Shade-tolerant | High | Zone 4a |
| smooth horsetail Equisetum laevigatum | Fern | 5 ft | Sun | Low | Zone 3b |
| smooth sumac Rhus glabra | Tree | 12 ft | Sun | Low | Zone 4a |
| softstem bulrush Schoenoplectus tabernaemontani | Grass or grass-like | 9 ft | Sun | High | Zone 3b |
| spotted St. Johnswort Hypericum punctatum | Wildflower (forb) | 3 ft | Shade-tolerant | Medium | Zone 4a |
| stalkless yellowcress Rorippa sessiliflora | Wildflower (forb) | 1.5 ft | Sun–part shade | High | Zone 12b |
| stiff goldenrod Oligoneuron rigidum | Wildflower (forb) | 3.6 ft | Sun–part shade | Medium | Zone 3a |
| strawcolored flatsedge Cyperus strigosus | Grass or grass-like | 3.2 ft | Sun | Medium | Zone 4a |
| swamp milkweed Asclepias incarnata | Wildflower (forb) | 4.9 ft | Sun | High | Zone 3b |
| swamp smartweed Polygonum hydropiperoides | Wildflower (forb) | — | Sun | Medium | Zone 10b |
| switchgrass Panicum virgatum | Grass or grass-like | 5 ft | Sun | Medium | Zone 3a |
| tall cinquefoil Potentilla arguta | Wildflower (forb) | 3 ft | Sun–part shade | Medium | Zone 3b |
| threelobe beggarticks Bidens tripartita | Wildflower (forb) | 3.5 ft | Sun–part shade | High | Zone 12a |
| trumpet creeper Campsis radicans | Vine | 2 ft | Sun | Low | Zone 6a |
| tufted loosestrife Lysimachia thyrsiflora | Wildflower (forb) | 2 ft | Sun–part shade | High | Zone 4a |
| upright sedge Carex stricta | Grass or grass-like | 4.2 ft | Shade-tolerant | Medium | Zone 3b |
| Virginia bluebells Mertensia virginica | Wildflower (forb) | 2.3 ft | Shade-tolerant | High | Zone 4b |
| Virginia creeper Parthenocissus quinquefolia | Vine | 1 ft | Sun–part shade | Low | Zone 4b |
| Virginia threeseed mercury Acalypha virginica | Wildflower (forb) | 3 ft | Sun–part shade | Medium | Zone 10b |
| Virginia wildrye Elymus virginicus | Grass or grass-like | 2.5 ft | Shade-tolerant | Medium | Zone 4b |
| water knotweed Polygonum amphibium | Wildflower (forb) | 1 in | Sun | High | Zone 5a |
| white avens Geum canadense | Wildflower (forb) | 3.9 ft | Shade-tolerant | Medium | Zone 4a |
| white doll's daisy Boltonia asteroides | Wildflower (forb) | 8 ft | Sun–part shade | Medium | Zone 3b |
| white oak Quercus alba | Tree | 100 ft | Sun–part shade | Medium | Zone 3a |
| white panicle aster Symphyotrichum lanceolatum | Wildflower (forb) | 6 ft | Sun–part shade | High | Zone 3b |
| white prairie clover Dalea candida | Wildflower (forb) | 2 ft | Sun–part shade | Medium | Zone 3b |
| whitegrass Leersia virginica | Grass or grass-like | 3.9 ft | Shade-tolerant | Medium | Zone 3a |
| wild bergamot Monarda fistulosa | Wildflower (forb) | 4.9 ft | Sun–part shade | High | Zone 4a |
| wild blue phlox Phlox divaricata | Wildflower (forb) | 3 ft | Sun–part shade | Medium | Zone 4a |
| wirestem muhly Muhlenbergia frondosa | Grass or grass-like | 2 ft | Shade-tolerant | Medium | Zone 3b |
| woodland bluegrass Poa sylvestris | Grass or grass-like | 3 ft | Shade-tolerant | High | Zone 4a |
| woolly plantain Plantago patagonica | Wildflower (forb) | 6 in | Sun | Low | Zone 12b |
No garden-ready natives match these filters. Try clearing one.
Other native species recorded here 210
PLANTS has no growing records for these, so light, moisture, height and zone filters cannot include them. Many are wild species seldom sold by nurseries.
Hidden while “Garden-ready only” is on.
- Allegheny monkeyflower Mimulus ringens
- amberique-bean Strophostyles helvola
- American bladdernut Staphylea trifolia
- American burnweed Erechtites hieraciifolius
- American lopseed Phryma leptostachya
- American spikenard Aralia racemosa
- Aunt Lucy Ellisia nyctelea
- bald spikerush Eleocharis erythropoda
- balsam groundsel Packera paupercula
- biennial beeblossom Oenothera gaura
- bigbract verbena Verbena bracteata
- birdfoot violet Viola pedata
- blackseed plantain Plantago rugelii
- bloody butcher Trillium recurvatum
- blue skullcap Scutellaria lateriflora
- bluejacket Tradescantia ohiensis
- bluntlobe cliff fern Woodsia obtusa
- bog yellowcress Rorippa palustris
- bottlebrush sedge Carex hystericina
- bristly greenbrier Smilax tamnoides
- bushy knotweed Polygonum ramosissimum
- button eryngo Eryngium yuccifolium
- Canada toadflax Nuttallanthus canadensis
- Canadian anemone Anemone canadensis
- Canadian blacksnakeroot Sanicula canadensis
- Canadian clearweed Pilea pumila
- Canadian honewort Cryptotaenia canadensis
- Canadian woodnettle Laportea canadensis
- Carolina anemone Anemone caroliniana
- Carolina draba Draba reptans
- Carolina horsenettle Solanum carolinense
- Carolina larkspur Delphinium carolinianum
- Carolina puccoon Lithospermum caroliniense
- carpenter's square Scrophularia marilandica
- clammy groundcherry Physalis heterophylla
- clammy hedgehyssop Gratiola neglecta
- clasping milkweed Asclepias amplexicaulis
- Clayton's sweetroot Osmorhiza claytonii
- Columbian watermeal Wolffia columbiana
- common boneset Eupatorium perfoliatum
- common cinquefoil Potentilla simplex
- common milkweed Asclepias syriaca
- common moonseed Menispermum canadense
- common pricklyash Zanthoxylum americanum
- common threeseed mercury Acalypha rhomboidea
- common yellow oxalis Oxalis stricta
- compassplant Silphium laciniatum
- Culver's root Veronicastrum virginicum
- Cuman ragweed Ambrosia psilostachya
- cutleaf evening primrose Oenothera laciniata
- cutleaf toothwort Cardamine concatenata
- Davis' sedge Carex davisii
- desert goosefoot Chenopodium pratericola
- Dillenius' ticktrefoil Desmodium glabellum
- Drummond's aster Symphyotrichum drummondii
- Dudley's rush Juncus dudleyi
- dutchman's breeches Dicentra cucullaria
- early buttercup Ranunculus fascicularis
- early goldenrod Solidago juncea
- eastern bottlebrush grass Elymus hystrix
- eastern poison ivy Toxicodendron radicans
- fall witchgrass Digitaria cognata
- false hop sedge Carex lupuliformis
- feathery false lily of the valley Maianthemum racemosum
- fescue sedge Carex festucacea
- fewleaf sunflower Helianthus occidentalis
- field pansy Viola bicolor
- field thistle Cirsium discolor
- flowering spurge Euphorbia corollata
- fourpoint evening primrose Oenothera rhombipetala
- foxtail barley Hordeum jubatum
- fragrant sumac Rhus aromatica
- fringed loosestrife Lysimachia ciliata
- Geyer's sandmat Chamaesyce geyeri
- golden zizia Zizia aurea
- great blue lobelia Lobelia siphilitica
- Great Plains flatsedge Cyperus lupulinus
- great ragweed Ambrosia trifida
- green carpetweed Mollugo verticillata
- green comet milkweed Asclepias viridiflora
- hairy hedgenettle Stachys pilosa
- hairy wildrye Elymus villosus
- heartleaf skullcap Scutellaria ovata
- heavy sedge Carex gravida
- hedge false bindweed Calystegia sepium
- Heller's rosette grass Dichanthelium oligosanthes
- hoary frostweed Helianthemum bicknellii
- hoary ticktrefoil Desmodium canescens
- hoary verbena Verbena stricta
- hyssopleaf hedgenettle Stachys aspera
- hyssopleaf hedgenettle Stachys hyssopifolia
- Illinois ticktrefoil Desmodium illinoense
- Indian-tobacco Lobelia inflata
- inflated narrow-leaf sedge Carex grisea
- lanceleaf fogfruit Phyla lanceolata
- largeflower bellwort Uvularia grandiflora
- lateflowering thoroughwort Eupatorium serotinum
- lesser yellow lady's slipper Cypripedium parviflorum
- licorice bedstraw Galium circaezans
- longleaf groundcherry Physalis longifolia
- longstyle sweetroot Osmorhiza longistylis
- low serviceberry Amelanchier humilis
- lowland bladderfern Cystopteris protrusa
- man of the earth Ipomoea pandurata
- mat sandbur Cenchrus longispinus
- mayapple Podophyllum peltatum
- meadow garlic Allium canadense
- Mexican plum Prunus mexicana
- Michaux's croton Croton michauxii
- Missouri gooseberry Ribes missouriense
- Missouri violet Viola missouriensis
- Muhlenberg's sedge Carex muehlenbergii
- narrowleaf mountainmint Pycnanthemum tenuifolium
- neckweed Veronica peregrina
- New England aster Symphyotrichum novae-angliae
- nodding wakerobin Trillium flexipes
- northern dewberry Rubus flagellaris
- oneseed bur cucumber Sicyos angulatus
- pale beardtongue Penstemon pallidus
- pale dock Rumex altissimus
- paleleaf woodland sunflower Helianthus strumosus
- Pennsylvania pellitory Parietaria pensylvanica
- Pennsylvania sedge Carex pensylvanica
- plain gentian Gentiana alba
- plains snakecotton Froelichia floridana
- pleatleaf knotweed Polygonum tenue
- prairie blue-eyed grass Sisyrinchium campestre
- prairie groundsel Packera plattensis
- prairie ironweed Vernonia fasciculata
- prairie rose Rosa arkansana
- prairie sunflower Helianthus petiolaris
- prairie threeawn Aristida oligantha
- prairie violet Viola pedatifida
- purple meadow-rue Thalictrum dasycarpum
- purple milkwort Polygala sanguinea
- purplerocket Iodanthus pinnatifidus
- rabbit-tobacco Pseudognaphalium obtusifolium
- racemed milkwort Polygala polygama
- red columbine Aquilegia canadensis
- redwhisker clammyweed Polanisia dodecandra
- ribseed sandmat Chamaesyce glyptosperma
- rosy sedge Carex rosea
- rough barnyardgrass Echinochloa muricata
- rough false pennyroyal Hedeoma hispida
- roundseed St. Johnswort Hypericum sphaerocarpum
- rue anemone Thalictrum thalictroides
- sand bittercress Cardamine parviflora
- sand violet Viola affinis
- Schweinitz's flatsedge Cyperus schweinitzii
- seaside threeawn Aristida tuberculosa
- shining bedstraw Galium concinnum
- shortbeak sedge Carex brevior
- showy ticktrefoil Desmodium canadense
- silky dogwood Cornus obliqua
- sixweeks fescue Vulpia octoflora
- slender snakecotton Froelichia gracilis
- slender wedgescale Sphenopholis intermedia
- slender yellow woodsorrel Oxalis dillenii
- slenderleaf false foxglove Agalinis tenuifolia
- small pondweed Potamogeton pusillus
- smallflower fumewort Corydalis micrantha
- smooth oxeye Heliopsis helianthoides
- smooth Solomon's seal Polygonatum biflorum
- smooth ticktrefoil Desmodium laevigatum
- Spanish needles Bidens bipinnata
- spotted beebalm Monarda punctata
- spotted geranium Geranium maculatum
- spotted sandmat Chamaesyce maculata
- spreading chervil Chaerophyllum procumbens
- stiff sunflower Helianthus pauciflorus
- stiff tickseed Coreopsis palmata
- swamp dock Rumex verticillatus
- swamp verbena Verbena hastata
- sweet coneflower Rudbeckia subtomentosa
- sweetscented joe pye weed Eutrochium purpureum
- tall blazing star Liatris aspera
- tall thimbleweed Anemone virginiana
- tall thistle Cirsium altissimum
- tall thoroughwort Eupatorium altissimum
- tall tickseed Coreopsis tripteris
- thin paspalum Paspalum setaceum
- tufted lovegrass Eragrostis pectinacea
- violet woodsorrel Oxalis violacea
- Virginia dwarfdandelion Krigia virginica
- Virginia groundcherry Physalis virginiana
- Virginia pepperweed Lepidium virginicum
- Virginia strawberry Fragaria virginiana
- Virginia tephrosia Tephrosia virginiana
- western tansymustard Descurainia pinnata
- white fawnlily Erythronium albidum
- white heath aster Symphyotrichum ericoides
- white snakeroot Ageratina altissima
- white vervain Verbena urticifolia
- whitehair rosette grass Dichanthelium villosissimum
- whitemouth dayflower Commelina erecta
- wholeleaf rosinweed Silphium integrifolium
- whorled milkweed Asclepias verticillata
- whorled milkwort Polygala verticillata
- whorled mountainmint Pycnanthemum verticillatum
- widowsfrill Silene stellata
- wild cucumber Echinocystis lobata
- wild yam Dioscorea villosa
- winged lythrum Lythrum alatum
- winged pigweed Cycloloma atriplicifolium
- witchgrass Panicum capillare
- woman's tobacco Antennaria plantaginifolia
- woodbine Parthenocissus vitacea
- woodland lettuce Lactuca floridana
- yellow giant hyssop Agastache nepetoides
- yellowseed false pimpernel Lindernia dubia
Also listed as native and introduced here 3
PLANTS labels these species both native and introduced in this state: some forms are native and others were brought in from elsewhere. Most gardeners should choose plants from the main list.
- annual ragweedAmbrosia artemisiifolia
- climbing false buckwheatPolygonum scandens
- Kentucky bluegrassPoa pratensis
Compared with Illinois
The typical county is the median of the 102 Illinois counties with PLANTS county records; the statewide figure counts every species native anywhere in the state. More species is not better or worse: counties differ in size, habitat and how thoroughly they have been surveyed.
| Measure | Mercer County | Typical county | Statewide |
|---|---|---|---|
| Native species | 379 | 641 | 1,909 |
| Garden-ready natives | 169 | 272 | 652 |
| Tree | 41 | — | 187 |
| Shrub | 14 | — | 96 |
| Wildflower (forb) | 234 | — | 1,015 |
| Grass or grass-like | 67 | — | 444 |
| Vine | 17 | — | 79 |
| Fern | 6 | — | 88 |
Neighboring counties
Counties that share a ZIP code with Mercer County.
- Henderson County, IL 285 garden-ready
- Henry County, IL 271 garden-ready
- Knox County, IL 217 garden-ready
- Rock Island County, IL 211 garden-ready
- Warren County, IL 146 garden-ready
Source & data date
- Source
- USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).
- Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.
- USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
- Citation
- USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.
- Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
- Data date
- Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
- Zones
- USDA Plant Hardiness Zone Map (2023) ZIP table: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 3, 2026. Plant zones on this site are our estimate, not the official map.
- Scope
- Mercer County (county FIPS 17131), Illinois. 379 native species from PLANTS county distribution records; garden-ready = species with a PLANTS characteristics record.
- Method
- A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources