California

• Alameda 06001
  1,856 taxa Open ↗
• Alpine 06003
  1,174 taxa Open ↗
• Amador 06005
  1,226 taxa Open ↗
• Butte 06007
  2,704 taxa Open ↗
• Calaveras 06009
  1,227 taxa Open ↗
• Colusa 06011
  1,330 taxa Open ↗
• Contra Costa 06013
  1,712 taxa Open ↗
• Del Norte 06015
  1,424 taxa Open ↗
• El Dorado 06017
  1,950 taxa Open ↗
• Fresno 06019
  2,373 taxa Open ↗

Showing 2,101–2,150 of 9,954.

• 
  Centaurea melitensis L. Introduced CEME2

  Maltese star-thistle · Asteraceae 44 counties
• 
  Centaurea nigra L. Introduced CENI2

  lesser knapweed · Asteraceae 1 county
• 
  Centaurea nigrescens Willd. Introduced CENI3

  Tyrol knapweed · Asteraceae 14 counties
• 
  Centaurea solstitialis L. Introduced CESO3

  yellow star-thistle · Asteraceae 49 counties
• 
  Centaurea stoebe L. Introduced CEST8

  spotted knapweed · Asteraceae 36 counties
• 
  Centaurea stoebe L. ssp. micranthos (Gugler) Hayek Introduced CESTM

  spotted knapweed · Asteraceae 36 counties
• 
  Centaurea sulphurea Willd. Introduced CESU

  sulphur knapweed · Asteraceae 5 counties
• 
  Centaurea virgata Lam. Introduced CEVI

  squarrose knapweed · Asteraceae 10 counties
• 
  Centaurea virgata Lam. ssp. squarrosa (Willd.) Gugler Introduced CEVIS2

  squarrose knapweed · Asteraceae 10 counties
• ⚘
  Centaurea ×pouzinii DC. [aspera × calcitrapa] Introduced CEPO8

  knapweed · Asteraceae 1 county
• 
  Centaurium arizonicum (A. Gray) A. Heller Native CEAR12

  Arizona centaury · Gentianaceae 1 county
• 
  Centaurium davyi (Jeps.) Abrams Native CEDA

  Davy's centaury · Gentianaceae 15 counties
• 
  Centaurium erythraea Rafn Introduced CEER5

  European centaury · Gentianaceae 3 counties
• 
  Centaurium exaltatum (Griseb.) W. Wight ex Piper Native CEEX

  desert centaury · Gentianaceae 17 counties
• 
  Centaurium muehlenbergii (Griseb.) W. Wight ex Piper Native CEMU2

  Muhlenberg's centaury · Gentianaceae 35 counties
• 
  Centaurium namatophilum Reveal, C.R. Broome & Beatley Native CENA2

  springloving centaury · Gentianaceae 1 county
• 
  Centaurium tenuiflorum (Hoffmanns. & Link) Fritsch Introduced CETE9

  slender centaury · Gentianaceae 1 county
• 
  Centaurium trichanthum (Griseb.) B.L. Rob. Native CETR2

  alkali centaury · Gentianaceae 16 counties
• 
  Centaurium venustum (A. Gray) B.L. Rob. Native CEVE3

  charming centaury · Gentianaceae 32 counties
• 
  Centaurium venustum (A. Gray) B.L. Rob. ssp. abramsii Munz Native CEVEA

  charming centaury · Gentianaceae 25 counties
• 
  Centaurium venustum (A. Gray) B.L. Rob. ssp. venustum Native CEVEV

  charming centaury · Gentianaceae 6 counties
• 
  Centranthus ruber (L.) DC. Introduced CERU2

  red valerian · Valerianaceae 18 counties
• 
  Centromadia parryi (Greene) Greene Native CEPA21

  pappose tarweed · Asteraceae 21 counties
• 
  Centromadia parryi (Greene) Greene ssp. australis (D.D. Keck) B.G. Baldw. Native CEPAA

  pappose tarweed · Asteraceae 5 counties
• 
  Centromadia parryi (Greene) Greene ssp. congdonii (B.L. Rob. & Greenm.) B.G. Baldw. Native CEPAC

  Congdon's tarweed · Asteraceae 8 counties
• 
  Centromadia parryi (Greene) Greene ssp. parryi Native CEPAP4

  pappose tarweed · Asteraceae 14 counties
• 
  Centromadia parryi (Greene) Greene ssp. rudis (Greene) B.G. Baldw. Native CEPAR4

  pappose tarweed · Asteraceae 7 counties
• 
  Centromadia pungens (Hook. & Arn.) Greene Native CEPU14

  common tarweed · Asteraceae 36 counties
• 
  Centromadia pungens (Hook. & Arn.) Greene ssp. laevis (D.D. Keck) B.G. Baldw. Native CEPUL

  common tarweed · Asteraceae 4 counties
• 
  Centromadia pungens (Hook. & Arn.) Greene ssp. maritima (Greene) B.G. Baldw. Native CEPUM

  common tarweed · Asteraceae 14 counties
• 
  Centromadia pungens (Hook. & Arn.) Greene ssp. pungens Native CEPUP6

  common tarweed · Asteraceae 36 counties
• 
  Centromadia pungens (Hook. & Arn.) Greene ssp. septentrionalis (D.D. Keck) B.G. Baldw. Native CEPUS2

  common tarweed · Asteraceae 4 counties
• 
  Centrostegia thurberi A. Gray ex Benth. Native CETH3

  red triangles · Polygonaceae 15 counties
• 
  Cephalanthera austiniae (A. Gray) A. Heller Native CEAU

  phantom orchid · Orchidaceae 28 counties
• 
  Cephalanthus occidentalis L. Native CEOC2

  common buttonbush · Rubiaceae 30 counties
• 
  Cerastium arvense L. Both CEAR4

  field chickweed · Caryophyllaceae 16 counties
• 
  Cerastium arvense L. ssp. strictum (L.) Ugborogho Native CEARS2

  field chickweed · Caryophyllaceae 1 county
• 
  Cerastium beeringianum Cham. & Schltdl. Native CEBE2

  Bering chickweed · Caryophyllaceae 3 counties
• 
  Cerastium beeringianum Cham. & Schltdl. ssp. earlei (Rydb.) Hultén Native CEBEE

  Bering chickweed · Caryophyllaceae 3 counties
• 
  Cerastium dichotomum L. Introduced CEDI5

  forked chickweed · Caryophyllaceae 1 county
• 
  Cerastium fontanum Baumg. Introduced CEFO2

  common mouse-ear chickweed · Caryophyllaceae 26 counties
• 
  Cerastium fontanum Baumg. ssp. vulgare (Hartm.) Greuter & Burdet Introduced CEFOV2

  big chickweed · Caryophyllaceae 26 counties
• 
  Cerastium glomeratum Thuill. Introduced CEGL2

  sticky chickweed · Caryophyllaceae 48 counties
• 
  Ceratocephala testiculata (Crantz) Roth Introduced CETE5

  curveseed butterwort · Ranunculaceae 8 counties
• 
  Ceratonia siliqua L. Introduced CESI3

  St. John's bread · Fabaceae 3 counties
• 
  Ceratophyllum demersum L. Native CEDE4

  coon's tail · Ceratophyllaceae 33 counties
• 
  Ceratopteris thalictroides (L.) Brongn. Native CETH2

  watersprite · Parkeriaceae 1 county
• 
  Cercis orbiculata Greene Native CEOR9

  California redbud · Fabaceae 34 counties
• 
  Cercocarpus intricatus S. Watson Native CEIN7

  littleleaf mountain mahogany · Rosaceae 6 counties
• 
  Cercocarpus ledifolius Nutt. Native CELE3

  curl-leaf mountain mahogany · Rosaceae 29 counties