Equisetum giganteumL.

Southern Giant Horsetailgiant horsetail

WFO wfo-0001111455 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Equisetum giganteum, photographed by Matias Cabezas
fig. a Matias Cabezas, CC BY 4.0 / 2022-03-26 / obs. 184754938
Equisetum giganteum, photographed by Ezequiel Vera
fig. b Ezequiel Vera, CC BY 4.0 / obs. 164993366
Equisetum giganteum, photographed by Ezequiel Vera
fig. c Ezequiel Vera, CC BY 4.0 / obs. 160292512
Equisetum giganteum, photographed by Ezequiel Vera
fig. d Ezequiel Vera, CC BY 4.0 / obs. 160292875
Equisetum giganteum, photographed by Martin
fig. e Martin, CC0 1.0 / obs. 105843707
Equisetum giganteum, photographed by Gustavo Puente
fig. f Gustavo Puente, CC0 1.0 / obs. 99118286
Equisetum giganteum, photographed by Noelia
fig. g Noelia, CC BY 4.0 / obs. 61145384
Equisetum giganteum, photographed by Ezequiel Vera
fig. h Ezequiel Vera, CC BY 4.0 / obs. 56492867

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 29 botanical countries

Regions where Equisetum giganteum is native: Mexico Gulf, Mexico Southeast, Mexico Southwest, Argentina Northeast, Argentina Northwest, Argentina South, Belize, Bolivia, Brazil South, Brazil Southeast, Brazil West-Central, Chile Central, Chile North, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Nicaragua, Panamá, Paraguay, Peru, Uruguay, Venezuela Mexico GulfMexico SoutheastMexico SouthwestArgentina NortheastArgentina NorthwestArgentina SouthBelizeBoliviaBrazil SouthBrazil SoutheastBrazil West-CentralChile CentralChile NorthColombiaCosta RicaCubaDominican RepublicEcuadorEl SalvadorGuatemalaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruUruguayVenezuela
Native distribution of Equisetum giganteum, 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.
RegionTDWG codeContinent
Argentina Northeast AGE SOUTHERN AMERICA
Argentina Northwest AGW
Argentina South AGS
Belize BLZ
Bolivia BOL
Brazil South BZS
Brazil Southeast BZL
Brazil West-Central BZC
Chile Central CLC
Chile North CLN
Colombia CLM
Costa Rica COS
Cuba CUB
Dominican Republic DOM
Ecuador ECU
El Salvador ELS
Guatemala GUA
Haiti HAI
Honduras HON
Jamaica JAM
Nicaragua NIC
Panamá PAN
Paraguay PAR
Peru PER
Uruguay URU
Venezuela VEN
Mexico Gulf MXG NORTHERN AMERICA
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.

Where it actually grows measured, from 543 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 3.3 °C 8.4 °C 14.9 °C
Warmest month, mean daily high 17.8 °C 26.4 °C 30.6 °C
Annual rainfall 180 mm 1,150 mm 2,793 mm
Rainfall in the driest quarter 5 mm 171 mm 367 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 543 research-grade observations of Equisetum giganteum that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 26 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.

  • Equisetum bolivianum Gand.
  • Equisetum brasiliense Milde
  • Equisetum brasiliense f. nudum Milde
  • Equisetum brasiliense f. ramosum Milde
  • Equisetum brasiliense var. nudum (Milde) Milde
  • Equisetum brasiliense var. ramosum (Milde) Milde
  • Equisetum caracasanum DC.
  • Equisetum elongatum var. dolosum Milde
  • Equisetum elongatum var. scaberrimum Milde
  • Equisetum giganteum var. asperrimum Milde
  • Equisetum giganteum var. brasiliense (Milde) Milde
  • Equisetum giganteum var. caracasanum (DC.) Milde
  • Equisetum giganteum var. digitaliferum Pastore
  • Equisetum giganteum var. poeppigianum A.Braun ex Milde
  • Equisetum humboldtianum Fendl.
  • Equisetum humboldtii Poir.
  • Equisetum lechleri Milde
  • Equisetum martii Milde
  • Equisetum martii var. minus Milde
  • Equisetum poeppigianum Mett.
  • Equisetum ramosissimum Humb. & Bonpl. ex Willd.
  • Equisetum ramosissimum var. dolosum (Milde) Milde
  • Equisetum ramosissimum var. scandens (Gay) Milde
  • Equisetum tarapacanum Phil.

and 2 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.