Dianthera comataL.

marsh water-willow

WFO wfo-0000642863 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Dianthera comata, photographed by Trevor Van Loon
fig. a Trevor Van Loon, CC BY 4.0 / 2021-12-24 / obs. 176390505

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 35 botanical countries

Regions where Dianthera comata is native: Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southeast, Mexico Southwest, Argentina Northeast, Argentina Northwest, Belize, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Haiti, Honduras, Jamaica, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Suriname, Trinidad-Tobago, Uruguay, Venezuela Mexico CentralMexico GulfMexico NortheastMexico SoutheastMexico SouthwestArgentina NortheastArgentina NorthwestBelizeBoliviaBrazil NorthBrazil NortheastBrazil SouthBrazil SoutheastBrazil West-CentralColombiaCosta RicaCubaDominican RepublicEcuadorEl SalvadorFrench GuianaGuatemalaGuyanaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruPuerto RicoSurinameTrinidad-TobagoUruguayVenezuela
Native distribution of Dianthera comata, 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
Belize BLZ
Bolivia BOL
Brazil North BZN
Brazil Northeast BZE
Brazil South BZS
Brazil Southeast BZL
Brazil West-Central BZC
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
Nicaragua NIC
Panamá PAN
Paraguay PAR
Peru PER
Puerto Rico PUE
Suriname SUR
Trinidad-Tobago TRT
Uruguay URU
Venezuela VEN
Mexico Central MXC NORTHERN AMERICA
Mexico Gulf MXG
Mexico Northeast MXE
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 58 in flower of 58 examined

Proportion of examined Dianthera comata in flower, by month
Month In flower Examined Share 95% interval
Jan 2 2 too few examined
Feb 8 8 100% 68% to 100%
Mar 4 4 too few examined
Apr 8 8 100% 68% to 100%
May 0 0 too few examined
Jun 0 0 too few examined
Jul 6 6 100% 61% to 100%
Aug 2 2 too few examined
Sep 10 10 100% 72% to 100%
Oct 2 2 too few examined
Nov 8 8 100% 68% to 100%
Dec 8 8 100% 68% to 100%

Peak flowering in Feb. Each bar is the share of Dianthera comata 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. 58 of 58 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 6 months have fewer than 5 examined observations, so no proportion is drawn for them. 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.

Where it actually grows measured, from 133 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 12.2 °C 19.6 °C 24.3 °C
Warmest month, mean daily high 26.3 °C 29.8 °C 33.2 °C
Annual rainfall 1,363 mm 2,616 mm 4,510 mm
Rainfall in the driest quarter 50 mm 248 mm 623 mm

It is not found anywhere that gets close to freezing. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 133 research-grade observations of Dianthera comata 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. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 22 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.

  • Dianthera decumbens Sw. ex Nees
  • Dianthera humifusa (Sw.) J.F.Gmel.
  • Ecbolium comatum (L.) Kuntze
  • Ecbolium havanense Kuntze
  • Ecbolium moritzianum Kuntze
  • Justicia acuminata (Nees) Lindau
  • Justicia comata (L.) Lam.
  • Justicia comata Vell. ex Nees
  • Justicia humifusa Sw.
  • Justicia humilis Nees
  • Leptostachya comata (L.) Kostel.
  • Leptostachya comata (L.) Nees
  • Leptostachya comata var. humifusa (Sw.) Nees
  • Leptostachya martiana var. hispida Nees
  • Leptostachya martiana var. macrophylla Nees
  • Leptostachya martiniana Nees
  • Leptostachya parviflora Nees
  • Psacadocalymma comatum (L.) Bremek.
  • Rhytiglossa acuminata Nees
  • Rhytiglossa havanensis Nees
  • Stethoma comata (L.) Britton
  • Thalestris graminiformis Rizzini

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. USDA PLANTS Database. common name, checklist symbol JUCO7. public domain. 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.