Isocarpha oppositifolia(L.) Cass.

Rio Grande pearlhead

WFO wfo-0000071096 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 5 observations

This species has been photographed under an open licence only 5 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.

Isocarpha oppositifolia, photographed by Sebastián de Jesús Herrera Buenfil
fig. a Sebastián de Jesús Herrera Buenfil, CC BY 4.0 / 2021-06-24 / obs. 138823514
Isocarpha oppositifolia, photographed by Eric Knight
fig. b Eric Knight, CC BY 4.0 / obs. 71307938
Isocarpha oppositifolia, photographed by Eric Knight
fig. c Eric Knight, CC BY 4.0 / obs. 71307962
Isocarpha oppositifolia, photographed by Olvin Wilfredo Oyuela
fig. d Olvin Wilfredo Oyuela, CC BY-SA 4.0 / obs. 169816619
Isocarpha oppositifolia, photographed by Olvin Wilfredo Oyuela
fig. e Olvin Wilfredo Oyuela, CC BY-SA 4.0 / obs. 170605743
Isocarpha oppositifolia, photographed by Sam Kieschnick
fig. f Sam Kieschnick, CC BY 4.0 / obs. 128467815
Isocarpha oppositifolia, photographed by Sam Kieschnick
fig. g Sam Kieschnick, CC BY 4.0 / obs. 128467858
Isocarpha oppositifolia, photographed by Sam Kieschnick
fig. h Sam Kieschnick, CC BY 4.0 / obs. 128467904

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 23 botanical countries

Regions where Isocarpha oppositifolia is native: Mexico Gulf, Mexico Northeast, Mexico Southeast, Mexico Southwest, Texas, Aruba, Bahamas, Brazil North, Brazil Northeast, Cayman Is., Colombia, Costa Rica, Cuba, El Salvador, Guatemala, Honduras, Jamaica, Netherlands Antilles, Nicaragua, Panamá, Trinidad-Tobago, Venezuela, Venezuelan Antilles Mexico GulfMexico NortheastMexico SoutheastMexico SouthwestTexasBrazil NorthBrazil NortheastColombiaCosta RicaCubaEl SalvadorGuatemalaHondurasJamaicaNicaraguaPanamáTrinidad-TobagoVenezuela ArubaBahamasCayman Is.Netherlands AntillesVenezuelan Antilles
Native distribution of Isocarpha oppositifolia, 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
Aruba ARU SOUTHERN AMERICA
Bahamas BAH
Brazil North BZN
Brazil Northeast BZE
Cayman Is. CAY
Colombia CLM
Costa Rica COS
Cuba CUB
El Salvador ELS
Guatemala GUA
Honduras HON
Jamaica JAM
Netherlands Antilles NLA
Nicaragua NIC
Panamá PAN
Trinidad-Tobago TRT
Venezuela VEN
Venezuelan Antilles VNA
Mexico Gulf MXG NORTHERN AMERICA
Mexico Northeast MXE
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.

Flowering 48 in flower of 51 examined

Peak flowering in Jan. Each bar is the share of Isocarpha oppositifolia 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. 48 of 51 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 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.

Also published as 10 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.

  • Dunantia achyranthes DC.
  • Isocarpha angustata Griseb.
  • Isocarpha atriplicifolia subsp. glabrata (S.F.Blake) Borhidi
  • Isocarpha glabrata S.F.Blake
  • Isocarpha oppositifolia subsp. achyranthes (DC.) Borhidi
  • Isocarpha oppositifolia subsp. oppositifolia
  • Isocarpha oppositifolia var. achyranthes (DC.) D.J.Keil & Stuessy
  • Isocarpha oppositifolia var. glabrata (S.F.Blake) Borhidi
  • Isocarpha tricephala Cass.
  • Santolina oppositifolia L.

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.