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 201–250 of 1,109 (introduced).

• 
  Centaurea nigra L. Introduced CENI2

  lesser knapweed · Asteraceae 31 counties
• 
  Centaurea nigrescens Willd. Introduced CENI3

  Tyrol knapweed · Asteraceae 12 counties
• 
  Centaurea solstitialis L. Introduced CESO3

  yellow star-thistle · Asteraceae 7 counties
• 
  Centaurea stoebe L. Introduced CEST8

  spotted knapweed · Asteraceae 48 counties
• 
  Centaurea stoebe L. ssp. micranthos (Gugler) Hayek Introduced CESTM

  spotted knapweed · Asteraceae 48 counties
• 
  Centaurium erythraea Rafn Introduced CEER5

  European centaury · Gentianaceae 4 counties
• 
  Centaurium pulchellum (Sw.) Druce Introduced CEPU3

  branched centaury · Gentianaceae 7 counties
• 
  Cerastium fontanum Baumg. Introduced CEFO2

  common mouse-ear chickweed · Caryophyllaceae 66 counties
• 
  Cerastium fontanum Baumg. ssp. vulgare (Hartm.) Greuter & Burdet Introduced CEFOV2

  big chickweed · Caryophyllaceae 66 counties
• 
  Cerastium glomeratum Thuill. Introduced CEGL2

  sticky chickweed · Caryophyllaceae 16 counties
• 
  Cerastium semidecandrum L. Introduced CESE4

  fivestamen chickweed · Caryophyllaceae 3 counties
• 
  Cerastium tomentosum L. Introduced CETO2

  snow in summer · Caryophyllaceae 6 counties
• 
  Cercidiphyllum japonicum Siebold & Zucc. Introduced CEJA2

  katsura tree · Cercidiphyllaceae 2 counties
• 
  Chaenomeles speciosa (Sweet) Nakai Introduced CHSP12

  flowering quince · Rosaceae 10 counties
• 
  Chaenorhinum minus (L.) Lange Introduced CHMI

  dwarf snapdragon · Scrophulariaceae 42 counties
• 
  Chaiturus marrubiastrum (L.) Rchb. Introduced CHMA18

  lion's tail · Lamiaceae 11 counties
• 
  Chelidonium majus L. Introduced CHMA2

  celandine · Papaveraceae 62 counties
• 
  Chelidonium majus L. var. majus Introduced CHMAM

  celandine · Papaveraceae 62 counties
• 
  Chenopodium album L. var. album Introduced CHALA

  lambsquarters · Chenopodiaceae 67 counties
• 
  Chenopodium bonus-henricus L. Introduced CHBO

  good King Henry · Chenopodiaceae 1 county
• 
  Chenopodium ficifolium Sm. Introduced CHFI4

  figleaf goosefoot · Chenopodiaceae 2 counties
• 
  Chenopodium glaucum L. Introduced CHGL3

  oakleaf goosefoot · Chenopodiaceae 18 counties
• 
  Chenopodium murale L. Introduced CHMU2

  nettleleaf goosefoot · Chenopodiaceae 14 counties
• 
  Chenopodium opulifolium Schrad. ex W.D.J. Koch & Ziz Introduced CHOP

  seaport goosefoot · Chenopodiaceae 1 county
• 
  Chenopodium polyspermum L. Introduced CHPO

  manyseed goosefoot · Chenopodiaceae 1 county
• 
  Chenopodium polyspermum L. var. acutifolium (Sm.) Gaudich. Introduced CHPOA

  manyseed goosefoot · Chenopodiaceae 1 county
• 
  Chenopodium polyspermum L. var. obtusifolium Gaudich. Introduced CHPOO

  manyseed goosefoot · Chenopodiaceae 1 county
• 
  Chenopodium urbicum L. Introduced CHUR

  city goosefoot · Chenopodiaceae 11 counties
• 
  Chenopodium vulvaria L. Introduced CHVU

  stinking goosefoot · Chenopodiaceae 1 county
• 
  Chondrilla juncea L. Introduced CHJU

  rush skeletonweed · Asteraceae 6 counties
• 
  Chorispora tenella (Pall.) DC. Introduced CHTE2

  crossflower · Brassicaceae 3 counties
• ⚘
  Chrysanthemum ×morifolium Ramat. (pro sp.) Introduced CHMO14

  florist's daisy · Asteraceae 3 counties
• 
  Cichorium endivia L. Introduced CIEN

  cultivated endive · Asteraceae 3 counties
• 
  Cichorium intybus L. Introduced CIIN

  chicory · Asteraceae 64 counties
• 
  Cirsium arvense (L.) Scop. Introduced CIAR4

  Canada thistle · Asteraceae 61 counties
• 
  Cirsium vulgare (Savi) Ten. Introduced CIVU

  bull thistle · Asteraceae 64 counties
• 
  Citrullus lanatus (Thunb.) Matsum. & Nakai Introduced CILA3

  watermelon · Cucurbitaceae 10 counties
• 
  Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus Introduced CILAL

  watermelon · Cucurbitaceae 10 counties
• 
  Clematis terniflora DC. Introduced CLTE4

  sweet autumn virginsbower · Ranunculaceae 18 counties
• 
  Cleome hassleriana Chod. Introduced CLHA

  pink queen · Capparaceae 16 counties
• 
  Cleome ornithopodioides L., nom. inq. Introduced CLOR2

  bird spiderflower · Capparaceae 1 county
• 
  Cleome viscosa L. Introduced CLVI9

  Asian spiderflower · Capparaceae 2 counties
• 
  Clerodendrum trichotomum Thunb. Introduced CLTR

  harlequin glorybower · Verbenaceae 1 county
• 
  Clerodendrum trichotomum Thunb. var. ferrugineum Nakai Introduced CLTRF

  ferruginous clerodendrum · Verbenaceae 1 county
• 
  Coincya monensis (L.) Greuter & Burdet Introduced COMO9

  star-mustard · Brassicaceae 2 counties
• 
  Coincya monensis (L.) Greuter & Burdet ssp. recurvata (All.) Leadley Introduced COMOR

  star-mustard · Brassicaceae 2 counties
• 
  Coix lacryma-jobi L. Introduced COLA

  Job's tears · Poaceae 3 counties
• 
  Colutea arborescens L. Introduced COAR6

  bladder senna · Fabaceae 3 counties
• 
  Commelina communis L. Introduced COCO3

  Asiatic dayflower · Commelinaceae 54 counties
• 
  Conium maculatum L. Introduced COMA2

  poison hemlock · Apiaceae 36 counties