Pennsylvania

• Adams 42001
  1,101 taxa Open ↗
• Allegheny 42003
  1,943 taxa Open ↗
• Armstrong 42005
  1,126 taxa Open ↗
• Beaver 42007
  1,402 taxa Open ↗
• Bedford 42009
  1,989 taxa Open ↗
• Berks 42011
  2,115 taxa Open ↗
• Blair 42013
  1,613 taxa Open ↗
• Bradford 42015
  1,111 taxa Open ↗
• Bucks 42017
  2,298 taxa Open ↗
• Butler 42019
  1,422 taxa Open ↗

Showing 51–100 of 1,109 (introduced).

• 
  Amaranthus deflexus L. Introduced AMDE

  largefruit amaranth · Amaranthaceae 2 counties
• 
  Ambrosia artemisiifolia L. var. elatior (L.) Descourtils Introduced AMARE

  annual ragweed · Asteraceae 1 county
• 
  Ammi visnaga (L.) Lam. Introduced AMVI2

  toothpickweed · Apiaceae 1 county
• 
  Ammophila arenaria (L.) Link Introduced AMAR4

  European beachgrass · Poaceae 1 county
• ⚘
  Ampelopsis brevipedunculata (Maxim.) Trautv. Introduced AMBR7

  Amur peppervine · Vitaceae 7 counties
• 
  Anacyclus clavatus (Desf.) Pers. Introduced ANCL2

  whitebuttons · Asteraceae 1 county
• 
  Anagallis arvensis L. Introduced ANAR

  scarlet pimpernel · Primulaceae 36 counties
• 
  Anchusa arvensis (L.) M. Bieb. Introduced ANAR16

  small bugloss · Boraginaceae 1 county
• 
  Anchusa azurea Mill. Introduced ANAZ

  Italian bugloss · Boraginaceae 4 counties
• 
  Anchusa officinalis L. Introduced ANOF

  common bugloss · Boraginaceae 3 counties
• 
  Anethum graveolens L. Introduced ANGR2

  dill · Apiaceae 13 counties
• 
  Anthemis arvensis L. Introduced ANAR6

  corn chamomile · Asteraceae 46 counties
• 
  Anthemis cotula L. Introduced ANCO2

  stinking chamomile · Asteraceae 57 counties
• 
  Anthemis tinctoria L. Introduced ANTI

  golden chamomile · Asteraceae 15 counties
• 
  Anthoxanthum aristatum Boiss. Introduced ANAR7

  annual vernalgrass · Poaceae 6 counties
• 
  Anthoxanthum odoratum L. Introduced ANOD

  sweet vernalgrass · Poaceae 65 counties
• 
  Anthoxanthum odoratum L. ssp. odoratum Introduced ANODO2

  sweet vernalgrass · Poaceae 65 counties
• 
  Anthriscus cerefolium (L.) Hoffm. Introduced ANCE

  garden chervil · Apiaceae 3 counties
• 
  Anthriscus sylvestris (L.) Hoffm. Introduced ANSY

  wild chervil · Apiaceae 8 counties
• 
  Anthyllis vulneraria L. Introduced ANVU

  common kidneyvetch · Fabaceae 2 counties
• 
  Antirrhinum majus L. Introduced ANMA3

  garden snapdragon · Scrophulariaceae 9 counties
• 
  Apera spica-venti (L.) P. Beauv. Introduced APSP

  loose silkybent · Poaceae 2 counties
• 
  Apium graveolens L. Introduced APGR2

  wild celery · Apiaceae 5 counties
• 
  Apium graveolens L. var. dulce (Mill.) DC. Introduced APGRD

  wild celery · Apiaceae 5 counties
• 
  Aquilegia vulgaris L. Introduced AQVU

  European columbine · Ranunculaceae 33 counties
• 
  Arabidopsis thaliana (L.) Heynh. Introduced ARTH

  mouseear cress · Brassicaceae 42 counties
• 
  Arachis hypogaea L. Introduced ARHY

  peanut · Fabaceae 3 counties
• 
  Aralia chinensis L. Introduced ARCH12

  Chinese angelica tree · Araliaceae 1 county
• 
  Arctium lappa L. Introduced ARLA3

  greater burdock · Asteraceae 18 counties
• 
  Arctium minus Bernh. Introduced ARMI2

  lesser burdock · Asteraceae 63 counties
• 
  Arctium tomentosum Mill. Introduced ARTO

  woolly burdock · Asteraceae 5 counties
• 
  Arctium vulgare (Hill) Evans Introduced ARVU2

  woodland burdock · Asteraceae 15 counties
• 
  Arenaria serpyllifolia L. Introduced ARSE2

  thymeleaf sandwort · Caryophyllaceae 58 counties
• 
  Aristolochia clematitis L. Introduced ARCL

  birthwort · Aristolochiaceae 3 counties
• 
  Armoracia rusticana G. Gaertn., B. Mey. & Scherb. Introduced ARRU4

  horseradish · Brassicaceae 34 counties
• 
  Arnoseris minima (L.) Schweigg. & Körte Introduced ARMI3

  lamb succory · Asteraceae 1 county
• 
  Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl Introduced AREL3

  tall oatgrass · Poaceae 55 counties
• 
  Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl var. elatius Introduced ARELE

  tall oatgrass · Poaceae 55 counties
• 
  Artemisia absinthium L. Introduced ARAB3

  absinthium · Asteraceae 7 counties
• 
  Artemisia annua L. Introduced ARAN3

  sweet sagewort · Asteraceae 13 counties
• 
  Artemisia biennis Willd. var. biennis Introduced ARBIB

  biennial wormwood · Asteraceae 6 counties
• 
  Artemisia pontica L. Introduced ARPO4

  Roman wormwood · Asteraceae 7 counties
• 
  Artemisia stelleriana Besser Introduced ARST6

  oldwoman · Asteraceae 3 counties
• 
  Artemisia vulgaris L. Introduced ARVU

  common wormwood · Asteraceae 1 county
• 
  Arthraxon hispidus (Thunb.) Makino Introduced ARHI3

  small carpetgrass · Poaceae 9 counties
• 
  Asparagus officinalis L. Introduced ASOF

  garden asparagus · Liliaceae 54 counties
• 
  Asperugo procumbens L. Introduced ASPR

  German-madwort · Boraginaceae 2 counties
• 
  Asperula arvensis L. Introduced ASAR2

  blue woodruff · Rubiaceae 1 county
• 
  Aster tataricus L. f. Introduced ASTA

  Tatarian aster · Asteraceae 3 counties
• 
  Atriplex littoralis L. Introduced ATLI3

  grassleaf orache · Chenopodiaceae 4 counties