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 3,251–3,300 of 3,901.

• 
  Senecio viscosus L. Introduced SEVI2

  sticky ragwort · Asteraceae 13 counties
• 
  Senecio vulgaris L. Introduced SEVU

  old-man-in-the-Spring · Asteraceae 27 counties
• 
  Senna hebecarpa (Fernald) Irwin & Barneby Native SEHE3

  American senna · Fabaceae 49 counties
• 
  Senna marilandica (L.) Link Native SEMA11

  Maryland senna · Fabaceae 11 counties
• 
  Senna obtusifolia (L.) Irwin & Barneby Native SEOB4

  Java-bean · Fabaceae 3 counties
• 
  Sericocarpus asteroides (L.) Britton, Sterns & Poggenb. Native SEAS3

  toothed whitetop aster · Asteraceae 55 counties
• 
  Sericocarpus linifolius (L.) Britton, Sterns & Poggenb. Native SELI5

  narrowleaf whitetop aster · Asteraceae 6 counties
• 
  Sesbania herbacea (Mill.) McVaugh Native SEHE8

  bigpod sesbania · Fabaceae 2 counties
• 
  Sesuvium portulacastrum (L.) L. Native SEPO2

  shoreline seapurslane · Aizoaceae 1 county
• 
  Sesuvium portulacastrum (L.) L. var. portulacastrum Native SEPOP

  shoreline seapurslane · Aizoaceae 1 county
• 
  Setaria faberi Herrm. Introduced SEFA

  Japanese bristlegrass · Poaceae 45 counties
• 
  Setaria italica (L.) P. Beauv. Introduced SEIT

  foxtail millet · Poaceae 22 counties
• 
  Setaria parviflora (Poir.) Kerguélen Native SEPA10

  marsh bristlegrass · Poaceae 14 counties
• 
  Setaria pumila (Poir.) Roem. & Schult. Introduced SEPU8

  yellow foxtail · Poaceae 1 county
• 
  Setaria verticillata (L.) P. Beauv. Introduced SEVE3

  hooked bristlegrass · Poaceae 16 counties
• 
  Setaria verticilliformis Dunart. Introduced SEVE5

  barbed bristlegrass · Poaceae 1 county
• 
  Setaria viridis (L.) P. Beauv. Introduced SEVI4

  green bristlegrass · Poaceae 48 counties
• 
  Setaria viridis (L.) P. Beauv. var. major (Gaudin) Pospichal Introduced SEVIM

  green bristlegrass · Poaceae 14 counties
• 
  Setaria viridis (L.) P. Beauv. var. viridis Introduced SEVIV

  green bristlegrass · Poaceae 48 counties
• 
  Shepherdia canadensis (L.) Nutt. Native SHCA

  russet buffaloberry · Elaeagnaceae 2 counties
• 
  Sherardia arvensis L. Introduced SHAR2

  blue fieldmadder · Rubiaceae 10 counties
• 
  Sibbaldiopsis tridentata (Aiton) Rydb. Native SITR3

  shrubby fivefingers · Rosaceae 3 counties
• 
  Sicyos angulatus L. Native SIAN

  oneseed bur cucumber · Cucurbitaceae 47 counties
• 
  Sida acuta Burm. f. Native SIAC3

  common wireweed · Malvaceae 1 county
• 
  Sida hermaphrodita (L.) Rusby Native SIHE3

  Virginia fanpetals · Malvaceae 7 counties
• 
  Sida linifolia Cav. Introduced SILI6

  flaxleaf fanpetals · Malvaceae 1 county
• 
  Sida rhombifolia L. Native SIRH

  Cuban jute · Malvaceae 2 counties
• 
  Sida spinosa L. Native SISP

  prickly fanpetals · Malvaceae 28 counties
• 
  Sideritis romana L. Introduced SIRO3

  simplebeak ironwort · Lamiaceae 1 county
• 
  Silene antirrhina L. Native SIAN2

  sleepy silene · Caryophyllaceae 49 counties
• 
  Silene armeria L. Introduced SIAR

  sweet William silene · Caryophyllaceae 28 counties
• 
  Silene caroliniana Walter Native SICA6

  sticky catchfly · Caryophyllaceae 40 counties
• 
  Silene caroliniana Walter ssp. pensylvanica (Michx.) R.T. Clausen Native SICAP

  Pennsylvania catchfly · Caryophyllaceae 40 counties
• 
  Silene csereii Baumg. Introduced SICS

  Balkan catchfly · Caryophyllaceae 10 counties
• 
  Silene dichotoma Ehrh. Introduced SIDI2

  forked catchfly · Caryophyllaceae 23 counties
• 
  Silene dioica (L.) Clairville Introduced SIDI4

  red catchfly · Caryophyllaceae 5 counties
• 
  Silene gallica L. Introduced SIGA

  common catchfly · Caryophyllaceae 3 counties
• 
  Silene latifolia Poir. Introduced SILA21

  bladder campion · Caryophyllaceae 64 counties
• 
  Silene latifolia Poir. ssp. alba (Mill.) Greuter & Burdet Introduced SILAA3

  bladder campion · Caryophyllaceae 64 counties
• 
  Silene nivea (Nutt.) Muhl. ex Otth Native SINI

  evening campion · Caryophyllaceae 12 counties
• 
  Silene noctiflora L. Introduced SINO

  nightflowering silene · Caryophyllaceae 37 counties
• 
  Silene stellata (L.) W.T. Aiton Native SIST

  widowsfrill · Caryophyllaceae 57 counties
• 
  Silene virginica L. Native SIVI4

  fire pink · Caryophyllaceae 17 counties
• 
  Silene virginica L. var. virginica Native SIVIV

  fire pink · Caryophyllaceae 17 counties
• 
  Silene vulgaris (Moench) Garcke Introduced SIVU

  maidenstears · Caryophyllaceae 49 counties
• 
  Silphium laciniatum L. Native SILA3

  compassplant · Asteraceae 1 county
• 
  Silphium laciniatum L. var. laciniatum Native SILAL2

  compassplant · Asteraceae 1 county
• 
  Silphium perfoliatum L. Native SIPE2

  cup plant · Asteraceae 14 counties
• 
  Silphium perfoliatum L. var. perfoliatum Native SIPEP

  cup plant · Asteraceae 14 counties
• ⚘
  Silphium trifoliatum L. Native SITR7

  whorled rosinweed · Asteraceae 26 counties