Digitaria insularis(L.) Mez ex Ekman

sourgrass

WFO wfo-0000864051 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Digitaria insularis, photographed by stinger
fig. a stinger, CC BY 4.0 / 2021-03-10 / obs. 117540093
Digitaria insularis, photographed by stinger
fig. b stinger, CC BY 4.0 / obs. 117540013
Digitaria insularis, photographed by Jay Horn
fig. c Jay Horn, CC BY 4.0 / obs. 188646716
Digitaria insularis, photographed by Elliot Greiner
fig. d Elliot Greiner, CC BY 4.0 / obs. 181230819
Digitaria insularis, photographed by Kevin Faccenda
fig. e Kevin Faccenda, CC BY 4.0 / obs. 182532600
Digitaria insularis, photographed by Kevin Faccenda
fig. f Kevin Faccenda, CC BY 4.0 / obs. 182532349
Digitaria insularis, photographed by Kevin Faccenda
fig. g Kevin Faccenda, CC BY 4.0 / obs. 151944061
Digitaria insularis, photographed by Alfredo F. Fuentes Claros
fig. h Alfredo F. Fuentes Claros, CC0 1.0 / obs. 58410240

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 50 botanical countries

Regions where Digitaria insularis is native: Alabama, Arizona, Florida, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Texas, Argentina Northeast, Argentina Northwest, Aruba, Bahamas, Belize, Bermuda, 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, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward Is., Netherlands Antilles, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Southwest Caribbean, Suriname, Trinidad-Tobago, Turks-Caicos Is., Uruguay, Venezuela, Venezuelan Antilles, Windward Is. AlabamaArizonaFloridaMexico CentralMexico GulfMexico NortheastMexico NorthwestMexico SoutheastMexico SouthwestTexasArgentina NortheastArgentina NorthwestBelizeBoliviaBrazil NorthBrazil NortheastBrazil SouthBrazil SoutheastBrazil West-CentralColombiaCosta RicaCubaDominican RepublicEcuadorEl SalvadorFrench GuianaGuatemalaGuyanaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruPuerto RicoSouthwest CaribbeanSurinameTrinidad-TobagoUruguayVenezuela ArubaBahamasBermudaCayman Is.Leeward Is.Netherlands AntillesTurks-Caicos Is.Venezuelan AntillesWindward Is.
Native distribution of Digitaria insularis, 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
Bermuda BER
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
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
Turks-Caicos Is. TCI
Uruguay URU
Venezuela VEN
Venezuelan Antilles VNA
Windward Is. WIN
Alabama ALA NORTHERN AMERICA
Arizona ARI
Florida FLA
Mexico Central MXC
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southeast MXT
Mexico Southwest MXS
Texas TEX

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 285 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 9.9 °C 20.7 °C 21.7 °C
Warmest month, mean daily high 24.7 °C 26.8 °C 32.0 °C
Annual rainfall 568 mm 920 mm 2,226 mm
Rainfall in the driest quarter 39 mm 118 mm 379 mm

It is barely found anywhere that freezes. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 285 research-grade observations of Digitaria insularis 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 28 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.

  • Agrostis villosa Steud.
  • Andropogon fabricii Henrard
  • Andropogon insularis L.
  • Digitaria insularis (L.) Fedde
  • Digitaria leucophaea (Kunth) Stapf
  • Milium hirsutum P.Beauv.
  • Milium villosum Sw.
  • Monachne unilateralis Roem. & Schult.
  • Nardus dactyloides Roll.-Germ. ex Rottb.
  • Panicum duchaissingii Steud.
  • Panicum falsum Steud.
  • Panicum gavanianum Steud. ex Döll
  • Panicum insulare (L.) G.Mey.
  • Panicum insulare var. insulare
  • Panicum insulare var. leucophaeum (Kunth) Kuntze
  • Panicum insulare var. typicum Hack.
  • Panicum lanatum Rottb.
  • Panicum leucophaeum Kunth
  • Panicum saccharoides A.Rich.
  • Rhynchospora fabri (Rottb.) Steud.
  • Saccharum polystachyum Siebold ex Kunth
  • Schoenus fabri Rottb.
  • Syntherisma insulare (L.) Millsp.
  • Syntherisma insularis (L.) Millsp.

and 4 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.