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Native plants · Iowa

Native plants of Union County

216 plant species are recorded as native to Iowa in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in Union County by USDA PLANTS. 92 of them have growing records you can filter by light, moisture, height and estimated cold hardiness. 2 more species are listed as both native and introduced and kept in a separate section.

County summary · USDA PLANTS and Kew WCVP

Union County, Iowa

Native species
216 Typical Iowa county: 44 (median of 99 counties)
Garden-ready natives
92 Typical Iowa county: 24
Share by type (all 216 native species)
Percent of the 216 native species in each growth type
Tree 9% (20)
Shrub 3% (6)
Wildflower (forb) 62% (134)
Grass or grass-like 21% (45)
Vine 4% (8)
Fern 1% (3)

Wildflowers make up the largest share of the native list (62%), followed by grasses and grass-like plants (21%).

Recorded native ranges can include long-established populations that spread from gardens; check your state’s native plant society list for local guidance. How native status is decided.

ZIP codes mainly in this county fall in USDA hardiness zone 5b (2023 map).

The native plant list

Cold hardiness is estimated from each plant’s PLANTS minimum temperature. How we estimate it.

Garden-ready natives 92

Native species with PLANTS growing records (height, light, moisture, minimum temperature). “—” means PLANTS has no value.

Garden-ready native plants of Union County, Iowa
PlantType HeightLight Water useHardy to
American basswood Tilia americana Tree 100 ft Shade-tolerant Medium Zone 2b
American hazelnut Corylus americana Shrub 10 ft Sun–part shade Medium Zone 4a
American water horehound Lycopus americanus Wildflower (forb) 1.8 ft Shade-tolerant High Zone 3b
Bicknell's sedge Carex bicknellii Grass or grass-like 3.4 ft Shade-tolerant Low Zone 3b
big bluestem Andropogon gerardii Grass or grass-like 6 ft Sun Low 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
bluejoint Calamagrostis canadensis Grass or grass-like 4.9 ft Sun Medium Zone 4a
boxelder Acer negundo Tree 60 ft Shade-tolerant Medium Zone 2b
broadleaf rosette grass Dichanthelium latifolium Grass or grass-like 3.3 ft Sun–part shade Low Zone 3a
bur oak Quercus macrocarpa Tree 100 ft Sun–part shade Medium Zone 3b
butterfly milkweed Asclepias tuberosa Wildflower (forb) 2 ft Sun Low Zone 4a
calico aster Symphyotrichum lateriflorum Wildflower (forb) 4 ft Sun Medium Zone 4a
Canada goldenrod Solidago altissima Wildflower (forb) 5 ft Sun–part shade Medium Zone 4b
Canada wildrye Elymus canadensis Grass or grass-like 3 ft Shade-tolerant Medium Zone 3a
Canadian milkvetch Astragalus canadensis Wildflower (forb) 6 in Sun Medium Zone 3b
chinquapin oak Quercus muehlenbergii Tree 70 ft Sun Medium Zone 4a
common blue violet Viola sororia Wildflower (forb) 4 in Sun–part shade High Zone 4b
common blue wood aster Symphyotrichum cordifolium Wildflower (forb) 5 ft Sun Low Zone 3b
common goldstar Hypoxis hirsuta Wildflower (forb) 10 in Sun–part shade Medium Zone 4a
composite dropseed Sporobolus compositus Grass or grass-like 3 ft Sun Low Zone 3b
coralberry Symphoricarpos orbiculatus Shrub 2 ft Sun–part shade High Zone 5a
crested sedge Carex cristatella Grass or grass-like 3 ft Shade-tolerant High Zone 4a
devil's darning needles Clematis virginiana Vine 15 ft Sun–part shade Medium 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
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
false daisy Eclipta prostrata Wildflower (forb) 3.2 ft Sun–part shade Medium Zone 10b
field horsetail Equisetum arvense Fern 11 in Sun–part shade High Zone 3a
field pussytoes Antennaria neglecta Wildflower (forb) 1 ft Sun Low Zone 3b
flatstem spikerush Eleocharis compressa Grass or grass-like 2 ft Sun High Zone 4a
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
gray goldenrod Solidago nemoralis Wildflower (forb) 2 ft Sun Medium Zone 4a
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
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
inland rush Juncus interior Grass or grass-like 3 ft Sun–part shade Medium Zone 3b
jewelweed Impatiens capensis Wildflower (forb) 4.9 ft Shade-tolerant Medium Zone 10b
leadplant Amorpha canescens Shrub 4 ft Shade-tolerant Low Zone 3b
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
marsh muhly Muhlenbergia racemosa Grass or grass-like 3 ft Shade-tolerant Medium Zone 3b
Mexican muhly Muhlenbergia mexicana Grass or grass-like 3 ft Sun–part shade Medium Zone 4a
pale purple coneflower Echinacea pallida Wildflower (forb) 1.2 ft Sun Medium Zone 4a
partridge pea Chamaecrista fasciculata Wildflower (forb) 2.4 ft Shade-tolerant Medium Zone 7a
peachleaf willow Salix amygdaloides Tree 60 ft Sun High Zone 4a
Pennsylvania smartweed Polygonum pensylvanicum Wildflower (forb) 3.9 ft Sun Medium Zone 10b
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 blazing star Liatris pycnostachya Wildflower (forb) 3.5 ft Sun Medium Zone 4a
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 dropseed Sporobolus heterolepis Grass or grass-like 2.3 ft Sun–part shade Low Zone 3b
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
purple lovegrass Eragrostis spectabilis Grass or grass-like 11 in Sun Low Zone 3a
quaking aspen Populus tremuloides Tree 65 ft Sun High Zone 1a
roundhead lespedeza Lespedeza capitata Wildflower (forb) 2.6 ft Sun Low Zone 4b
rufous bulrush Scirpus pendulus Grass or grass-like 4 ft Sun Medium Zone 3b
sandbar willow Salix interior Tree 30 ft Sun — Zone 1a
sawtooth sunflower Helianthus grosseserratus Wildflower (forb) 5 ft Sun Medium Zone 3a
shingle oak Quercus imbricaria Tree 45 ft Sun Medium Zone 5b
sideoats grama Bouteloua curtipendula Grass or grass-like 3 ft Sun Medium Zone 3a
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 blue aster Symphyotrichum laeve Wildflower (forb) 4 ft Sun Medium Zone 3a
smooth horsetail Equisetum laevigatum Fern 5 ft Sun Low Zone 3b
spotted St. Johnswort Hypericum punctatum Wildflower (forb) 3 ft Shade-tolerant Medium Zone 4a
stiff goldenrod Oligoneuron rigidum Wildflower (forb) 3.6 ft Sun–part shade Medium Zone 3a
swamp milkweed Asclepias incarnata Wildflower (forb) 4.9 ft Sun High Zone 3b
sweet woodreed Cinna arundinacea Grass or grass-like 4.9 ft Shade-tolerant Low Zone 4a
switchgrass Panicum virgatum Grass or grass-like 5 ft Sun Medium Zone 3a
teal lovegrass Eragrostis hypnoides Grass or grass-like 4 in Sun High Zone 3b
threelobe beggarticks Bidens tripartita Wildflower (forb) 3.5 ft Sun–part shade High Zone 12a
Torrey's rush Juncus torreyi Grass or grass-like 3.1 ft Sun Medium Zone 3b
water knotweed Polygonum amphibium Wildflower (forb) 1 in Sun High Zone 5a
western wheatgrass Pascopyrum smithii Grass or grass-like 2 ft Sun Medium Zone 3a
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 prairie clover Dalea candida Wildflower (forb) 2 ft Sun–part shade Medium Zone 3b
white sagebrush Artemisia ludoviciana Wildflower (forb) 3 ft Sun Low Zone 4a
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

Other native species recorded here 124

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.

  • amberique-bean Strophostyles helvola
  • American burnweed Erechtites hieraciifolius
  • American stoneseed Lithospermum latifolium
  • aromatic aster Symphyotrichum oblongifolium
  • arrowhead rattlebox Crotalaria sagittalis
  • Aunt Lucy Ellisia nyctelea
  • Baldwin's ironweed Vernonia baldwinii
  • balsam groundsel Packera paupercula
  • bastard toadflax Comandra umbellata
  • beggarslice Hackelia virginiana
  • bigbract verbena Verbena bracteata
  • blackseed plantain Plantago rugelii
  • bloodroot Sanguinaria canadensis
  • bluejacket Tradescantia ohiensis
  • brittle bladderfern Cystopteris fragilis
  • buffalo clover Trifolium reflexum
  • buffalobur nightshade Solanum rostratum
  • button eryngo Eryngium yuccifolium
  • Canadian honewort Cryptotaenia canadensis
  • candle anemone Anemone cylindrica
  • Carolina horsenettle Solanum carolinense
  • Carolina larkspur Delphinium carolinianum
  • Carolina puccoon Lithospermum caroliniense
  • carpenter's square Scrophularia marilandica
  • clasping Venus' looking-glass Triodanis perfoliata
  • common moonseed Menispermum canadense
  • Culver's root Veronicastrum virginicum
  • downy phlox Phlox pilosa
  • dwarf chinquapin oak Quercus prinoides
  • dwarf larkspur Delphinium tricorne
  • eastern poison ivy Toxicodendron radicans
  • elmleaf goldenrod Solidago ulmifolia
  • feathery false lily of the valley Maianthemum racemosum
  • feverwort Triosteum perfoliatum
  • fiveangled dodder Cuscuta pentagona
  • foxtail barley Hordeum jubatum
  • foxtail prairie clover Dalea leporina
  • fringed loosestrife Lysimachia ciliata
  • great ragweed Ambrosia trifida
  • green dragon Arisaema dracontium
  • groovestem Indian plantain Arnoglossum plantagineum
  • hairy hedgenettle Stachys pilosa
  • hairy woodland brome Bromus pubescens
  • heartleaf four o'clock Mirabilis nyctaginea
  • heavy sedge Carex gravida
  • hedge false bindweed Calystegia sepium
  • Heller's rosette grass Dichanthelium oligosanthes
  • hoary frostweed Helianthemum bicknellii
  • hoary puccoon Lithospermum canescens
  • hoary verbena Verbena stricta
  • honeyvine Cynanchum laeve
  • Jersey tea Ceanothus herbaceus
  • lanceleaf sage Salvia reflexa
  • largebracted plantain Plantago aristata
  • largeflower bellwort Uvularia grandiflora
  • leathery knotweed Polygonum achoreum
  • lesser yellow lady's slipper Cypripedium parviflorum
  • longbract spiderwort Tradescantia bracteata
  • longflower beeblossom Oenothera filiformis
  • mayapple Podophyllum peltatum
  • Mead's sedge Carex meadii
  • Missouri gooseberry Ribes missouriense
  • narrowleaf mountainmint Pycnanthemum tenuifolium
  • neckweed Veronica peregrina
  • New England aster Symphyotrichum novae-angliae
  • northern bugleweed Lycopus uniflorus
  • Northern Idaho biscuitroot Lomatium orientale
  • Norwegian cinquefoil Potentilla norvegica
  • Nuttall's prairie parsley Polytaenia nuttallii
  • pale dock Rumex altissimus
  • Pennsylvania pellitory Parietaria pensylvanica
  • poverty dropseed Sporobolus vaginiflorus
  • prairie false dandelion Nothocalais cuspidata
  • prairie rose Rosa arkansana
  • prairie threeawn Aristida oligantha
  • prairie violet Viola pedatifida
  • purple meadow-rue Thalictrum dasycarpum
  • purple milkweed Asclepias purpurascens
  • purple milkwort Polygala sanguinea
  • red columbine Aquilegia canadensis
  • rock muhly Muhlenbergia sobolifera
  • rough barnyardgrass Echinochloa muricata
  • rough false pennyroyal Hedeoma hispida
  • shortbeak arrowhead Sagittaria brevirostra
  • shortbeak sedge Carex brevior
  • silverleaf Indian breadroot Pediomelum argophyllum
  • skyblue aster Symphyotrichum oolentangiense
  • slender yellow woodsorrel Oxalis dillenii
  • slenderleaf false foxglove Agalinis tenuifolia
  • slimflower scurfpea Psoralidium tenuiflorum
  • slimleaf panicgrass Dichanthelium linearifolium
  • small skullcap Scutellaria parvula
  • smooth oxeye Heliopsis helianthoides
  • soft-hair marbleseed Onosmodium bejariense
  • spotted sandmat Chamaesyce maculata
  • spotted water hemlock Cicuta maculata
  • spreading dogbane Apocynum androsaemifolium
  • stiff tickseed Coreopsis palmata
  • swamp verbena Verbena hastata
  • sweetscented joe pye weed Eutrochium purpureum
  • tall thistle Cirsium altissimum
  • Texas goldentop Euthamia gymnospermoides
  • tufted lovegrass Eragrostis pectinacea
  • violet lespedeza Lespedeza violacea
  • Virginia bunchflower Veratrum virginicum
  • Virginia groundcherry Physalis virginiana
  • Virginia pepperweed Lepidium virginicum
  • Virginia springbeauty Claytonia virginica
  • Virginia strawberry Fragaria virginiana
  • western silver aster Symphyotrichum sericeum
  • white fawnlily Erythronium albidum
  • white four o'clock Mirabilis albida
  • white heath aster Symphyotrichum ericoides
  • white vervain Verbena urticifolia
  • wholeleaf rosinweed Silphium integrifolium
  • whorled milkweed Asclepias verticillata
  • whorled milkwort Polygala verticillata
  • wild yam Dioscorea villosa
  • winged lythrum Lythrum alatum
  • witchgrass Panicum capillare
  • Wolf's spikerush Eleocharis wolfii
  • wood lily Lilium philadelphicum
  • yellow pimpernel Taenidia integerrima
  • yellowseed false pimpernel Lindernia dubia
Also listed as native and introduced here 2

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.

Compared with Iowa

The typical county is the median of the 99 Iowa 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.

Native species counts, Union County and Iowa
MeasureUnion CountyTypical countyStatewide
Native species 216 44 1,374
Garden-ready natives 92 24 496
Tree 20 — 110
Shrub 6 — 72
Wildflower (forb) 134 — 779
Grass or grass-like 45 — 298
Vine 8 — 55
Fern 3 — 60

Neighboring counties

Counties that share a ZIP code with Union County.

Look up another ZIP

Matches your ZIP to the county it mostly lies in, then lists the plants recorded as native to your state (Kew’s World Checklist and USDA PLANTS) and recorded in that county by USDA PLANTS.

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
Union County (county FIPS 19175), Iowa. 216 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

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