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 2,351–2,400 of 3,901.

• 
  Nelumbo lutea Willd. Native NELU

  American lotus · Nelumbonaceae 4 counties
• 
  Neobeckia aquatica (Eaton) Greene Native NEAQ2

  lakecress · Brassicaceae 1 county
• 
  Nepeta cataria L. Introduced NECA2

  catnip · Lamiaceae 65 counties
• 
  Neslia paniculata (L.) Desv. Introduced NEPA3

  ballmustard · Brassicaceae 1 county
• 
  Nicandra physalodes (L.) Scop. Introduced NIPH

  apple of Peru · Solanaceae 10 counties
• 
  Nicotiana alata Link & Otto Introduced NIAL

  jasmine tobacco · Solanaceae 1 county
• 
  Nicotiana longiflora Cav. Introduced NILO

  longflower tobacco · Solanaceae 2 counties
• 
  Nicotiana rustica L. Introduced NIRU

  Aztec tobacco · Solanaceae 1 county
• 
  Nicotiana tabacum L. Introduced NITA

  cultivated tobacco · Solanaceae 2 counties
• 
  Nigella damascena L. Introduced NIDA

  devil in the bush · Ranunculaceae 6 counties
• 
  Nonea rosea (M. Bieb.) Link Introduced NORO

  rose monkswort · Boraginaceae 1 county
• 
  Nonea vesicaria (L.) Rchb. Introduced NOVE

  red monkswort · Boraginaceae 1 county
• 
  Nuphar lutea (L.) Sm. Native NULU

  yellow pond-lily · Nymphaeaceae 57 counties
• 
  Nuphar lutea (L.) Sm. ssp. advena (Aiton) Kartesz & Gandhi Native NULUA

  yellow pond-lily · Nymphaeaceae 1 county
• 
  Nuphar lutea (L.) Sm. ssp. pumila (Timm) E.O. Beal Native NULUP2

  yellow pond-lily · Nymphaeaceae 1 county
• 
  Nuphar lutea (L.) Sm. ssp. variegata (Durand) E.O. Beal Native NULUV

  varigated yellow pond-lily · Nymphaeaceae 1 county
• 
  Nuttallanthus canadensis (L.) D.A. Sutton Native NUCA

  Canada toadflax · Scrophulariaceae 19 counties
• ⚘
  Nymphaea odorata Aiton Native NYOD

  American white waterlily · Nymphaeaceae 29 counties
• 
  Nymphoides cordata (Elliott) Fernald Native NYCO

  little floatingheart · Menyanthaceae 3 counties
• 
  Nymphoides peltata (S.G. Gmel.) Kuntze Introduced NYPE

  yellow floatingheart · Menyanthaceae 2 counties
• 
  Nyssa sylvatica Marshall Native NYSY

  blackgum · Cornaceae 64 counties
• 
  Obolaria virginica L. Native OBVI

  Virginia pennywort · Gentianaceae 22 counties
• 
  Ocimum basilicum L. Introduced OCBA

  sweet basil · Lamiaceae 9 counties
• 
  Oclemena acuminata (Michx.) Greene Native OCAC

  whorled wood aster · Asteraceae 45 counties
• 
  Oclemena nemoralis (Aiton) Greene Native OCNE2

  bog aster · Asteraceae 2 counties
• 
  Oenothera argillicola Mack. Native OEAR

  shale barren evening primrose · Onagraceae 5 counties
• 
  Oenothera biennis L. Native OEBI

  common evening primrose · Onagraceae 58 counties
• 
  Oenothera fruticosa L. Native OEFR

  narrowleaf evening primrose · Onagraceae 55 counties
• 
  Oenothera fruticosa L. ssp. fruticosa Native OEFRF

  narrowleaf evening primrose · Onagraceae 49 counties
• 
  Oenothera fruticosa L. ssp. tetragona (Roth) W.L. Wagner Native OEFRT

  narrowleaf evening primrose · Onagraceae 45 counties
• 
  Oenothera gaura W.L. Wagner & Hoch Native OEGA

  biennial beeblossom · Onagraceae 49 counties
• 
  Oenothera glazioviana Micheli Introduced OEGL

  redsepal evening primrose · Onagraceae 3 counties
• 
  Oenothera grandiflora L'Hér. ex Aiton Native OEGR4

  largeflower evening primrose · Onagraceae 2 counties
• 
  Oenothera laciniata Hill Native OELA

  cutleaf evening primrose · Onagraceae 10 counties
• 
  Oenothera nutans Atk. & Bartlett Native OENU2

  nodding evening primrose · Onagraceae 39 counties
• 
  Oenothera oakesiana (A. Gray) J.W. Robbins ex S. Watson & J.M. Coult. Native OEOA

  Oakes' evening primrose · Onagraceae 10 counties
• 
  Oenothera parviflora L. Native OEPA5

  northern evening primrose · Onagraceae 21 counties
• 
  Oenothera perennis L. Native OEPE

  little evening primrose · Onagraceae 63 counties
• 
  Oenothera pilosella Raf. Native OEPI2

  meadow evening primrose · Onagraceae 14 counties
• 
  Oenothera pilosella Raf. ssp. pilosella Native OEPIP

  meadow evening primrose · Onagraceae 13 counties
• 
  Oenothera speciosa Nutt. Native OESP2

  pinkladies · Onagraceae 5 counties
• 
  Oenothera triloba Nutt. Native OETR2

  stemless evening primrose · Onagraceae 1 county
• 
  Oenothera villosa Thunb. Native OEVI

  hairy evening primrose · Onagraceae 4 counties
• 
  Oenothera villosa Thunb. ssp. villosa Native OEVIV

  hairy evening primrose · Onagraceae 4 counties
• 
  Oligoneuron rigidum (L.) Small Native OLRI

  stiff goldenrod · Asteraceae 15 counties
• 
  Oligoneuron rigidum (L.) Small var. rigidum Native OLRIR

  stiff goldenrod · Asteraceae 15 counties
• 
  Omalotheca sylvatica (L.) Sch. Bip. & F.W. Schultz Native OMSY

  woodland arctic cudweed · Asteraceae 1 county
• 
  Onoclea sensibilis L. Native ONSE

  sensitive fern · Dryopteridaceae 67 counties
• 
  Ononis spinosa L. Introduced ONSP

  spiny restharrow · Fabaceae 1 county
• 
  Onopordum acanthium L. Introduced ONAC

  Scotch cottonthistle · Asteraceae 5 counties