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 1,651–1,700 of 2,748 (native).

• 
  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
• 
  Nyssa sylvatica Marshall Native NYSY

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

  Virginia pennywort · Gentianaceae 22 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 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
• 
  Onosmodium bejariense DC. ex A. DC. Native ONBE

  soft-hair marbleseed · Boraginaceae 6 counties
• 
  Onosmodium bejariense DC. ex A. DC. var. hispidissimum (Mack.) B.L. Turner Native ONBEH

  softhair marbleseed · Boraginaceae 6 counties
• 
  Onosmodium virginianum (L.) A. DC. Native ONVI2

  wild Job's tears · Boraginaceae 2 counties
• 
  Ophioglossum engelmannii Prantl Native OPEN

  limestone adderstongue · Ophioglossaceae 1 county
• 
  Ophioglossum pusillum Raf. Native OPPU3

  northern adderstongue · Ophioglossaceae 33 counties
• 
  Ophioglossum vulgatum L. Native OPVU

  southern adderstongue · Ophioglossaceae 8 counties
• 
  Opuntia humifusa (Raf.) Raf. Native OPHU

  devil's-tongue · Cactaceae 14 counties
• 
  Orobanche uniflora L. Native ORUN

  oneflowered broomrape · Orobanchaceae 55 counties
• 
  Orontium aquaticum L. Native ORAQ

  goldenclub · Araceae 37 counties
• 
  Orthilia secunda (L.) House Native ORSE

  sidebells wintergreen · Pyrolaceae 33 counties
• 
  Oryzopsis asperifolia Michx. Native ORAS

  roughleaf ricegrass · Poaceae 24 counties
• 
  Osmorhiza claytonii (Michx.) C.B. Clarke Native OSCL

  Clayton's sweetroot · Apiaceae 53 counties
• 
  Osmorhiza longistylis (Torr.) DC. Native OSLO

  longstyle sweetroot · Apiaceae 60 counties
• 
  Osmunda cinnamomea L. Native OSCI

  cinnamon fern · Osmundaceae 66 counties
• 
  Osmunda claytoniana L. Native OSCL2

  interrupted fern · Osmundaceae 67 counties
• 
  Osmunda regalis L. Native OSRE

  royal fern · Osmundaceae 62 counties
• 
  Osmunda regalis L. var. spectabilis (Willd.) A. Gray Native OSRES

  royal fern · Osmundaceae 62 counties