Common Allergy-Triggering Plants Include:

  • Agave[1]
    • American (Agave americana)
    • Blue (Agave azul)
    • Mexican (Agave attenuate)
    • Tequila (Agave tequilana)
  • Alder
    • Black (Alder glutinosa)
    • Green (Alnus viridis)
    • Red (Alder rubra)
  • Amaranth (See Pigweed)
  • Ash (See also Poison Ash and Poison Oak.)
    • American/White (Fraxinus americana)
    • Blue (Fraxinus quadrangulata)
    • European (Fraxinus excelsior)
  • Asparagus[2] (See also Poisonous Plants.)
    • Garden (Asparagus officinalis)
    • Sprenger’s (Asparagus aethiopicus)
  • Aspen/Cottonwood/Poplar
    • Black Poplar (Populus nigra)
    • Chinese Necklace Poplar (Populus lasiocarpa)
    • Eastern Cottonwood (Populus deltoides)
    • European Aspen (Populus tremula)
    • Fremont’s cottonwood (Populus fremontii)
    • Plains Cottonwood (Populus sargentii)
    • Quaking Aspen (Populus tremuloides)
    • Wilson’s Poplar (Populus wilsonii)
  • Aster-family plants
    • Painted Daisy (Tanacetum coccineum)
    • Tansy (Tanacetum vulgare)
  • Beech
    • American (Fagus grandifolia)
    • European (Fagus sylvatica) (See also Poisonous Plants.)
    • Purple (Fagus sylvatica “Purpurea”)
  • Birch
    • American White/Downy (Betula pubescens)
    • Asian White (Betula platyphylla)
    • Dog (Betula pumila)
    • Dwarf (Betula nana)
    • Himalayan (Betula utilis)
    • Japanese/Siberian (Betula platyphylla)
    • Paper (Betula papyrifera)
    • Red/Water (Betula occidentalis)
    • River (Betula nigra)
    • Silver (Betula pendula)
    • Swamp (Betula alleghaniensis)
    • Sweet/Cherry (Betula lenta)
    • Yellow (Betula alleghaniensis)
  • Black-Eyed Susan (Rudbeckia hirta)
  • Box Elder/Box Elder Maple (Acer negundo)
  • Cashew Tree[3] (Anacardium occidentale)
  • Cedar
    • Mountain (See Juniper)
  • Chamomile
    • German/Italian (Matricaria chamomilla)
    • Moroccan (Cladanthus mixtus)
    • Roman (Chamaemelum nobile)
    • Wile/Pineapple Weed (Matricaria discoidea)
    • Yellow (Cota tinctoria)
  • Chrysanthemum (See also Daisy.)
    • Crown Daisy/Garland Chrysanthemum (Glebionis coronaria)
    • Dalmatian Chrysanthemum (Tanacetum cinerariifolium)
    • Florist’s Daisy (Chrysanthemum morifolium)
    • Max Chrysanthemum (Chrysanthemum maximum)
    • Persian Chrysanthemum (Chrysanthemum coccineum)
    • Tricolor Daisy (Chrysanthemum carinatum)
  • Clematis (See Old man’s Beard.)
  • Cocklebur (Xanthium strumarium)
  • Copperleaf (Acalypha wilkesiana) (See also Poisonous Plants.)
  • Cottonwood (See Aspen)
  • Croton, Garden (Codiaeum variegatum) (See also Poisonous Plants.)
  • Cypress
    • Arizona (Cupressus arizonica)
    • Italian/ Mediterranean (Cupressus sempervirens)
    • Lawson (Chamaecyparis lawsoniana)
    • Leyland (Cupressus × leylandii)
    • Monterey (Cupressus macrocarpa)
  • Daisy (See also Chrysanthemum.)
    • Corn (Glebionis segetum)
    • English (Bellis perennis)
    • Paris (Argyranthemum frutescens)
    • Shasta (Leucanthemum × superbum)
  • Elm
    • American (Ulmus americana)
    • Dutch (Ulmus × hollandica)
    • English (Ulmus procera)
  • Fig, Common (Ficus carica)
  • Flax (Linum usitatissimum)[4]
  • Forsythia (Forsythia × intermedia)
  • Fragrant Sumac (Rhus aromatica) (See also Poison Oak.)
  • Goldenrod
    • Canada (Solidago canadensis)
    • Gray (Solidago nemoralis)
    • Showy (Solidago speciosa)
  • Grass
    • Bahama/Bermuda (Cynodon dactylon)
    • Black Bent/Redtop (Agrostis gigantea)
    • Cat/Orchard (Dactylis glomerata)
    • Couch/Scutch (Elymus repens)
    • Desert Saltgrass (Distichlis spicata)
    • Fescue (Festuca arundinacea)
    • Johnson (Sorghum halepense)
    • June (Koeleria macrantha)
    • Kentucky Bluegrass (Poa pratensis)
    • Ryegrass
    • English/Winter (Lolium perenne)
    • Italian (Lolium multiflorum)
    • Sweet Vernal (Anthoxanthum odoratum)
    • Timothy (Phleum pratense)
    • Zoysia
    • Japanese/Korean (Zoysia japonica)
    • Manila (Zoysia matrella)
    • Mascarene (Zoysia tenuifolia)
  • Hickory
    • Kingnut (Carya laciniosa)
    • Shagbark (Carya ovata)
    • Southern Shagbark (Carya carolinae-septentrionalis)
  • Hogweed, Giant (Heracleum mantegazzianum)
  • Holly
    • American (Ilex opaca)
    • Chinese (Ilex cornuta)
    • Japanese (Ilex crenata)
    • Winterberry (Ilex verticillata)
  • Jasmine
    • Star (Trachelospermum jasminoides)
    • Winter (Jasminum nudiflorum)
    • Yellow (Jasminum humile)
  • Juniper/Mountain Cedar (Juniperus ashei)
  • Lily, Dragon (Dracunculus vulgaris) (For other lilies, see Poisonous Plants.)
  • Maple
    • “English Sycamore” (Acer pseudoplatanus)
    • Red (Acer rubrum)
    • Silver (Acer saccharinum)
    • Sugar (Acer saccharum)
  • Mulberry
    • Black (Morus nigra)
    • Red (Morus rubra)
    • White (Morus alba)
  • Nettle
    • Stinging (Urtica dioica)
    • Wood (Laportea canadensis)
  • Oak (See also Poisonous Plants.)
    • Chestnut (Quercus montana)
    • Scarlet (Quercus coccinea)
    • White (Quercus alba)
  • Old Man’s Beard/Pepper Vine (Clematis ligusticifolia)
  • Palm
    • Date (Phoenix dactylifera)
    • Fishtail (Caryota mitis)
    • Phoenix (Phoenix canariensis)
  • Pecan/Hickory (Carya illinoinensis)
  • Pepper, Chili (Capsicum annuum)
  • Pigweed/Amaranth
    • Powell (Amaranthus powelii)
    • Palmer (Amaranthus palmeri)
    • Redroot (Amaranthus retroflexus)
    • Smooth (Amaranthus hybridus)
    • Spiny (Amaranthus spinosus)
    • Tumbleweed (Amaranthus albus)
  • Pine
    • Eastern White (Pinus strobus)
    • Jack (Pinus banksiana)
    • Loblolly (Pinus taeda)
    • Lodgepole (Pinus contorta)
    • Longleaf (Pinus palustris)
    • Pitch (Pinus rigida)
    • Ponderosa (Pinus ponderosa)
    • Red (Pinus resinosa)
    • Shortleaf (Pinus echinata)
    • Slash (Pinus elliottii)
    • Sugar (Pinus lambertiana)
    • Virginia (Pinus virginiana)
    • Western White (Pinus monticola)
  • Poplar (See Aspen.)
  • Poinsettia (Euphorbia pulcherrima) (See also Wood Spurge. For Sun Spurge, see Poisonous Plants.)
  • Poison Ash (Comocladia dodonaea)
  • Poison Oak (See also Fragrant Sumac.)
    • Manzanillo (Toxicodendron striatum)
    • Poison Ivy (Toxicodendron radicans)
    • Poison Ivy, Western (Toxicodendron rydbergii)
    • Poison Oak, Atlantic/Eastern (Toxicodendron pubescens)
    • Poison Oak, Pacific/Western (Toxicodendron diversilobum)
    • Poison Sumac/Poison Ash/Thunderwood (Toxicodendron vernix)
  • Poodle-Dog Bush (Eriodictyon parryi)
  • Ragweed
    • Common (Ambrosia artemisiifolia)
    • Giant (Ambrosia trifida)
  • Rue (Ruta graveolens) (See also Poisonous Plants.)
  • Sagebrush (See also Wormwood)
    • Big (Artemisia tridentata)
    • Sweet Wormwood (Artemisia annua)
    • White (Artemisia ludoviciana)
  • Santa Maria (Parthenium hysterophorus)
  •  Spiderwort
    • Purple Heart (Tradescantia purpurea)
    • Wandering Jew (Tradescantia pallida)
  • Stinging Brush (Dendrocnide moroides)
  • Stinging Nettle (See Nettle: Stinging.)
  • Sunflower, Common (Helianthus annuus)
  • Sycamore
    • American (Platanus occidentalis)
    • Arizona (Platanus wrightii)
    • California/Western (Platanus racemosa)
    • English (See Maple)
    • London Planetree (Platanus x acerifolia)
  • Tree of Heaven (Ailanthus altissima)
  • Tumbleweed
    • Russian (Salsola kali)
    • Russian Pigweed (Axyris amaranthoides)
  • Tung Tree (Vernicia fordii) (See also Poisonous Plants.)
  • Velvet Bean/Cowhage/ (Mucuna pruriens)
  • Walnut
    • Black (Juglans nigra)
    • English (Juglans regia)
  • Willow
    • Black (Salix nigra)
    • Weeping (Salix babylonica)
    • White (Salix alba)
  • Wood Spurge (Euphorbia amygdaloides)
  • Wormwood (Artemisia absinthium; see also Sagebrush)

Notes:

[1] Can cause skin irritation.

[2] The berries can cause dermal and gastrointestinal reactions.

[3] The fruit has a mildly toxic and irritating shell.

[4] Mostly causes skin irritation. But various reports suggest that eating too much of it can cause a build up of toxins.