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 2,951–3,000 of 3,901.

• 
  Rapistrum rugosum (L.) All. Introduced RARU

  annual bastardcabbage · Brassicaceae 2 counties
• 
  Ratibida columnifera (Nutt.) Wooton & Standl. Native RACO3

  upright prairie coneflower · Asteraceae 2 counties
• 
  Ratibida pinnata (Vent.) Barnhart Native RAPI

  pinnate prairie coneflower · Asteraceae 4 counties
• 
  Reseda alba L. Introduced REAL

  white upright mignonette · Resedaceae 2 counties
• 
  Reseda lutea L. Introduced RELU

  yellow mignonette · Resedaceae 12 counties
• 
  Reseda luteola L. Introduced RELU2

  weld · Resedaceae 3 counties
• 
  Reseda odorata L. Introduced REOD

  garden mignonette · Resedaceae 2 counties
• 
  Reseda phyteuma L. Introduced REPH

  rampion mignonette · Resedaceae 1 county
• 
  Rhamnus alnifolia L'Hér. Native RHAL

  alderleaf buckthorn · Rhamnaceae 17 counties
• 
  Rhamnus cathartica L. Introduced RHCA3

  common buckthorn · Rhamnaceae 17 counties
• 
  Rhamnus davurica Pall. Introduced RHDA

  Dahurian buckthorn · Rhamnaceae 3 counties
• 
  Rhamnus davurica Pall. ssp. davurica Introduced RHDAD2

  Dahurian buckthorn · Rhamnaceae 3 counties
• 
  Rhamnus lanceolata Pursh Native RHLA

  lanceleaf buckthorn · Rhamnaceae 8 counties
• 
  Rhamnus lanceolata Pursh ssp. lanceolata Native RHLAL3

  lanceleaf buckthorn · Rhamnaceae 8 counties
• 
  Rheum rhabarbarum L. Introduced RHRH2

  garden rhubarb · Polygonaceae 6 counties
• 
  Rhexia mariana L. Native RHMA

  Maryland meadowbeauty · Melastomataceae 3 counties
• 
  Rhexia mariana L. var. mariana Native RHMAM2

  Maryland meadowbeauty · Melastomataceae 3 counties
• 
  Rhexia virginica L. Native RHVI

  handsome Harry · Melastomataceae 26 counties
• 
  Rhodiola rosea L. Native RHRO3

  roseroot stonecrop · Crassulaceae 2 counties
• 
  Rhododendron arborescens (Pursh) Torr. Native RHAR3

  smooth azalea · Ericaceae 13 counties
• 
  Rhododendron atlanticum (Ashe) Rehder Native RHAT

  dwarf azalea · Ericaceae 1 county
• 
  Rhododendron calendulaceum (Michx.) Torr. Native RHCA4

  flame azalea · Ericaceae 2 counties
• 
  Rhododendron canadense (L.) Torr. Native RHCA6

  rhodora · Ericaceae 9 counties
• 
  Rhododendron canescens (Michx.) Sweet Native RHCA7

  mountain azalea · Ericaceae 11 counties
• 
  Rhododendron maximum L. Native RHMA4

  great laurel · Ericaceae 57 counties
• 
  Rhododendron periclymenoides (Michx.) Shinners Native RHPE4

  pink azalea · Ericaceae 63 counties
• 
  Rhododendron prinophyllum (Small) Millais Native RHPR

  early azalea · Ericaceae 46 counties
• 
  Rhododendron viscosum (L.) Torr. Native RHVI2

  swamp azalea · Ericaceae 23 counties
• 
  Rhodotypos scandens (Thunb.) Makino Introduced RHSC3

  jetbead · Rosaceae 11 counties
• 
  Rhus aromatica Aiton Native RHAR4

  fragrant sumac · Anacardiaceae 12 counties
• 
  Rhus aromatica Aiton var. aromatica Native RHARA2

  fragrant sumac · Anacardiaceae 12 counties
• 
  Rhus copallinum L. Native RHCO

  winged sumac · Anacardiaceae 55 counties
• 
  Rhus copallinum L. var. copallinum Native RHCOC

  winged sumac · Anacardiaceae 27 counties
• 
  Rhus copallinum L. var. latifolia Engl. Native RHCOL2

  winged sumac · Anacardiaceae 53 counties
• 
  Rhus glabra L. Native RHGL

  smooth sumac · Anacardiaceae 61 counties
• 
  Rhus typhina L. Native RHTY

  staghorn sumac · Anacardiaceae 64 counties
• 
  Rhus ×borealis Greene [glabra × typhina] Native RHBO

  hybrid sumac · Anacardiaceae 1 county
• 
  Rhynchospora alba (L.) Vahl Native RHAL3

  white beaksedge · Cyperaceae 32 counties
• 
  Rhynchospora capillacea Torr. Native RHCA11

  needle beaksedge · Cyperaceae 6 counties
• 
  Rhynchospora capitellata (Michx.) Vahl Native RHCA12

  brownish beaksedge · Cyperaceae 38 counties
• 
  Rhynchospora fusca (L.) W.T. Aiton Native RHFU

  brown beaksedge · Cyperaceae 2 counties
• 
  Rhynchospora globularis (Chapm.) Small Native RHGL2

  globe beaksedge · Cyperaceae 1 county
• 
  Rhynchospora gracilenta A. Gray Native RHGR

  slender beaksedge · Cyperaceae 1 county
• 
  Rhynchospora recognita (Gale) Kral Native RHRE8

  globe beaksedge · Cyperaceae 6 counties
• 
  Ribes americanum Mill. Native RIAM2

  American black currant · Grossulariaceae 49 counties
• 
  Ribes aureum Pursh Native RIAU

  golden currant · Grossulariaceae 13 counties
• 
  Ribes aureum Pursh var. villosum DC. Native RIAUV

  golden currant · Grossulariaceae 13 counties
• 
  Ribes cynosbati L. Native RICY

  eastern prickly gooseberry · Grossulariaceae 45 counties
• 
  Ribes glandulosum Grauer Native RIGL

  skunk currant · Grossulariaceae 24 counties
• 
  Ribes hirtellum Michx. Native RIHI

  hairystem gooseberry · Grossulariaceae 28 counties