Ruellia elegansPoir.

WFO wfo-0001263659 Accepted WFO 2026-06 4 photographs CC BY / CC BY-SA

Plate 1 figs. a–d · 3 observations

This species has been photographed under an open licence only 3 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.

Ruellia elegans, photographed by Ong Jyh Seng
fig. a Ong Jyh Seng, CC BY-SA 4.0 / 2019-09-05 / obs. 50503268

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 3 botanical countries

Regions where Ruellia elegans is native: Brazil Northeast, Brazil South, Brazil Southeast Brazil NortheastBrazil SouthBrazil Southeast
Native distribution of Ruellia elegans, 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
Brazil Northeast BZE SOUTHERN AMERICA
Brazil South BZS
Brazil Southeast BZL

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 98 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 8.7 °C 12.6 °C 21.3 °C
Warmest month, mean daily high 26.5 °C 29.8 °C 32.3 °C
Annual rainfall 1,288 mm 1,908 mm 4,342 mm
Rainfall in the driest quarter 32 mm 107 mm 566 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 98 research-grade observations of Ruellia elegans 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 12 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.

  • Arrhostoxylon silvaccola var. montanum Nees
  • Arrhostoxylum elegans (Poir.) Bremek. & Nann.-Bremek.
  • Arrhostoxylum formosa (Bonpl.) Nees
  • Arrhostoxylum formosum Nees
  • Arrhostoxylum roseum Nees
  • Arrhostoxylum silvaccola var. montanum Nees
  • Asystasia formosa T.Anderson
  • Ruellia formosa Andrews
  • Ruellia rosea (Nees) W.Bull
  • Ruellia speciosa Mart. ex Nees
  • Ruellia superba D.Dietr.
  • Stemonacanthus formosus T.Anderson

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. 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.