Senna occidentalis(L.) Link

septicweed

WFO wfo-0000164430 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Senna occidentalis, photographed by 雲一百香果
fig. a 雲一百香果, CC BY 4.0 / 2022-06-04 / obs. 203143646
Senna occidentalis, photographed by Robert Taylor
fig. b Robert Taylor, CC BY 4.0 / obs. 192112443
Senna occidentalis, photographed by TreeClouds Permaculture
fig. c TreeClouds Permaculture, CC BY 4.0 / obs. 177202191
Senna occidentalis, photographed by Navaneeth Sini George
fig. d Navaneeth Sini George, CC BY 4.0 / obs. 178771874
Senna occidentalis, photographed by Agnes Trekker
fig. e Agnes Trekker, CC0 1.0 / obs. 172536897
Senna occidentalis, photographed by Иван Ковтун Ivan Kovtun
fig. f Иван Ковтун Ivan Kovtun, CC BY 4.0 / obs. 171844853
Senna occidentalis, photographed by S.MORE
fig. g S.MORE, CC0 1.0 / obs. 174687861
Senna occidentalis, photographed by Sabarni Sarker
fig. h Sabarni Sarker, CC BY 4.0 / obs. 159135435

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 45 botanical countries

Regions where Senna occidentalis is native: Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Argentina Northeast, Argentina Northwest, Aruba, Bahamas, Belize, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Cayman Is., Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, French Guiana, Galápagos, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward Is., Netherlands Antilles, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Southwest Caribbean, Suriname, Trinidad-Tobago, Uruguay, Venezuela, Venezuelan Antilles, Windward Is. Mexico CentralMexico GulfMexico NortheastMexico NorthwestMexico SoutheastMexico SouthwestArgentina NortheastArgentina NorthwestBelizeBoliviaBrazil NorthBrazil NortheastBrazil SouthBrazil SoutheastBrazil West-CentralColombiaCosta RicaCubaDominican RepublicEcuadorEl SalvadorFrench GuianaGuatemalaGuyanaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruPuerto RicoSouthwest CaribbeanSurinameTrinidad-TobagoUruguayVenezuela ArubaBahamasCayman Is.GalápagosLeeward Is.Netherlands AntillesVenezuelan AntillesWindward Is.
Native distribution of Senna occidentalis, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Argentina Northeast AGE SOUTHERN AMERICA
Argentina Northwest AGW
Aruba ARU
Bahamas BAH
Belize BLZ
Bolivia BOL
Brazil North BZN
Brazil Northeast BZE
Brazil South BZS
Brazil Southeast BZL
Brazil West-Central BZC
Cayman Is. CAY
Colombia CLM
Costa Rica COS
Cuba CUB
Dominican Republic DOM
Ecuador ECU
El Salvador ELS
French Guiana FRG
Galápagos GAL
Guatemala GUA
Guyana GUY
Haiti HAI
Honduras HON
Jamaica JAM
Leeward Is. LEE
Netherlands Antilles NLA
Nicaragua NIC
Panamá PAN
Paraguay PAR
Peru PER
Puerto Rico PUE
Southwest Caribbean SWC
Suriname SUR
Trinidad-Tobago TRT
Uruguay URU
Venezuela VEN
Venezuelan Antilles VNA
Windward Is. WIN
Mexico Central MXC NORTHERN AMERICA
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southeast MXT
Mexico Southwest MXS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 266 in flower of 331 examined

Peak flowering in Sep. Each bar is the share of Senna occidentalis observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 266 of 331 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Also published as 25 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Cassia caroliniana Walter
  • Cassia ciliata Raf.
  • Cassia falcata L.
  • Cassia foetida Willemet
  • Cassia glaucescens Hoffmanns.
  • Cassia macradenia Collad.
  • Cassia obliquifolia Schrank
  • Cassia occidentalis (L.) Rose
  • Cassia occidentalis L.
  • Cassia occidentalis var. arista sensu Hassk., non DC.
  • Cassia occidentalis var. aristata Collad.
  • Cassia occidentalis var. glabra Vogel
  • Cassia papulosa Hoffmanns.
  • Cassia planisiliqua Burm.f.
  • Cassia planisiliqua L.
  • Cassia plumieri DC.
  • Diallobus falcatus (L.) Raf.
  • Ditramexa occidentalis Britton & Rose
  • Ditremexa caroliniana (Walter) Raf.
  • Ditremexa fetida Raf.
  • Ditremexa occidentalis (L.) Britton & Rose
  • Psilorhegma planisiliqua (L.) Britton & Rose
  • Senna andhrica P.V.Ramana, J.Swamy & M.Ahmed.
  • Senna occidentalis var. andhrica (P.V.Ramana, J.Swamy & M.Ahmed.) K.W.Jiang

and 1 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.