Iowa

• Adair 19001
  393 taxa Open ↗
• Adams 19003
  200 taxa Open ↗
• Allamakee 19005
  118 taxa Open ↗
• Appanoose 19007
  38 taxa Open ↗
• Audubon 19009
  225 taxa Open ↗
• Benton 19011
  21 taxa Open ↗
• Black Hawk 19013
  33 taxa Open ↗
• Boone 19015
  146 taxa Open ↗
• Bremer 19017
  24 taxa Open ↗
• Buchanan 19019
  16 taxa Open ↗

Showing 1,951–2,000 of 2,225.

• 
  Sonchus oleraceus L. Introduced SOOL

  common sowthistle · Asteraceae 7 counties
• 
  Sophora nuttalliana B.L. Turner Native SONU

  silky sophora · Fabaceae 1 county
• 
  Sorghastrum nutans (L.) Nash Native SONU2

  Indiangrass · Poaceae 48 counties
• 
  Sorghum bicolor (L.) Moench Introduced SOBI2

  sorghum · Poaceae 1 county
• 
  Sorghum halepense (L.) Pers. Introduced SOHA

  Johnsongrass · Poaceae 8 counties
• 
  Sparganium androcladum (Engelm.) Morong Native SPAN

  branched bur-reed · Sparganiaceae 1 county
• 
  Sparganium angustifolium Michx. Native SPAN2

  narrowleaf bur-reed · Sparganiaceae 1 county
• 
  Sparganium eurycarpum Engelm. Native SPEU

  broadfruit bur-reed · Sparganiaceae 13 counties
• 
  Spartina pectinata Bosc ex Link Native SPPE

  prairie cordgrass · Poaceae 37 counties
• 
  Spermacoce glabra Michx. Native SPGL2

  smooth false buttonweed · Rubiaceae 1 county
• 
  Spermolepis inermis (Nutt. ex DC.) Mathias & Constance Native SPIN

  Red River scaleseed · Apiaceae 2 counties
• 
  Sphaeralcea coccinea (Nutt.) Rydb. Native SPCO

  scarlet globemallow · Malvaceae 2 counties
• 
  Sphaeralcea coccinea (Nutt.) Rydb. ssp. coccinea Native SPCOC

  scarlet globemallow · Malvaceae 2 counties
• 
  Sphenopholis intermedia (Rydb.) Rydb. Native SPIN3

  slender wedgescale · Poaceae 20 counties
• 
  Sphenopholis nitida (Biehler) Scribn. Native SPNI

  shiny wedgescale · Poaceae 1 county
• 
  Sphenopholis obtusata (Michx.) Scribn. Native SPOB

  prairie wedgescale · Poaceae 32 counties
• 
  Spiraea alba Du Roi Native SPAL2

  white meadowsweet · Rosaceae 6 counties
• 
  Spiraea alba Du Roi var. alba Native SPALA

  white meadowsweet · Rosaceae 5 counties
• 
  Spiraea alba Du Roi var. latifolia (Aiton) Dippel Native SPALL

  white meadowsweet · Rosaceae 1 county
• 
  Spiranthes cernua (L.) Rich. Native SPCE

  nodding lady's tresses · Orchidaceae 7 counties
• 
  Spiranthes lacera (Raf.) Raf. Native SPLA4

  northern slender lady's tresses · Orchidaceae 5 counties
• 
  Spiranthes lucida (H.H. Eaton) Ames Native SPLU2

  shining lady's tresses · Orchidaceae 1 county
• 
  Spiranthes magnicamporum Sheviak Native SPMA5

  Great Plains lady's tresses · Orchidaceae 4 counties
• 
  Spiranthes romanzoffiana Cham. Native SPRO

  hooded lady's tresses · Orchidaceae 1 county
• 
  Spiranthes vernalis Engelm. & A. Gray Native SPVE

  spring lady's tresses · Orchidaceae 1 county
• 
  Spirodela polyrrhiza (L.) Schleid. Native SPPO

  common duckmeat · Lemnaceae 12 counties
• 
  Sporobolus clandestinus (Biehler) Hitchc. Native SPCL

  rough dropseed · Poaceae 3 counties
• 
  Sporobolus compositus (Poir.) Merr. Native SPCO16

  composite dropseed · Poaceae 29 counties
• 
  Sporobolus compositus (Poir.) Merr. var. compositus Native SPCOC2

  composite dropseed · Poaceae 29 counties
• 
  Sporobolus cryptandrus (Torr.) A. Gray Native SPCR

  sand dropseed · Poaceae 27 counties
• 
  Sporobolus heterolepis (A. Gray) A. Gray Native SPHE

  prairie dropseed · Poaceae 34 counties
• 
  Sporobolus neglectus Nash Native SPNE2

  puffsheath dropseed · Poaceae 30 counties
• 
  Sporobolus vaginiflorus (Torr. ex A. Gray) Alph. Wood Native SPVA

  poverty dropseed · Poaceae 22 counties
• 
  Sporobolus vaginiflorus (Torr. ex A. Gray) Alph. Wood var. vaginiflorus Native SPVAV2

  poverty dropseed · Poaceae 22 counties
• 
  Stachys aspera Michx. Native STAS

  hyssopleaf hedgenettle · Lamiaceae 1 county
• 
  Stachys hyssopifolia Michx. Native STHY3

  hyssopleaf hedgenettle · Lamiaceae 1 county
• 
  Stachys palustris L. Native STPA

  marsh hedgenettle · Lamiaceae 3 counties
• 
  Stachys pilosa Nutt. Native STPI6

  hairy hedgenettle · Lamiaceae 18 counties
• 
  Stachys pilosa Nutt. var. arenicola (Britton) G. Mulligan & D. Munro Native STPIA

  hairy hedgenettle · Lamiaceae 2 counties
• 
  Stachys pilosa Nutt. var. pilosa Native STPIP5

  hairy hedgenettle · Lamiaceae 18 counties
• 
  Stachys tenuifolia Willd. Native STTE

  smooth hedgenettle · Lamiaceae 7 counties
• 
  Staphylea trifolia L. Native STTR

  American bladdernut · Staphyleaceae 15 counties
• 
  Stellaria graminea L. Introduced STGR

  grass-like starwort · Caryophyllaceae 1 county
• 
  Stellaria longifolia Muhl. ex Willd. Native STLO

  longleaf starwort · Caryophyllaceae 3 counties
• 
  Stellaria longifolia Muhl. ex Willd. var. longifolia Native STLOL

  longleaf starwort · Caryophyllaceae 2 counties
• 
  Stellaria media (L.) Vill. Introduced STME2

  common chickweed · Caryophyllaceae 8 counties
• 
  Stellaria media (L.) Vill. ssp. media Introduced STMEM

  common chickweed · Caryophyllaceae 6 counties
• 
  Stenaria nigricans (Lam.) Terrell Native STNI6

  diamond-flowers · Rubiaceae 7 counties
• 
  Stenaria nigricans (Lam.) Terrell var. nigricans Native STNIN

  diamondflowers · Rubiaceae 7 counties
• 
  Strophostyles helvola (L.) Elliott Native STHE9

  amberique-bean · Fabaceae 15 counties