Cressa truxillensisKunth

spreading alkaliweed

WFO wfo-0001296772 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Cressa truxillensis, photographed by Ken-ichi Ueda
fig. a Ken-ichi Ueda, CC BY 4.0 / 2022-05-21 / obs. 199520395

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 24 botanical countries

Regions where Cressa truxillensis is native: Arizona, California, Mexican Pacific Is., Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Nevada, New Mexico, Oklahoma, Oregon, Texas, Utah, Argentina Northeast, Argentina Northwest, Argentina South, Bolivia, Chile Central, Chile North, Ecuador, Galápagos, Paraguay, Peru, Uruguay ArizonaCaliforniaMexico NortheastMexico NorthwestMexico SoutheastMexico SouthwestNevadaNew MexicoOklahomaOregonTexasUtahArgentina NortheastArgentina NorthwestArgentina SouthBoliviaChile CentralChile NorthEcuadorParaguayPeruUruguay Galápagos
Native distribution of Cressa truxillensis, 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
Arizona ARI NORTHERN AMERICA
California CAL
Mexican Pacific Is. MXI
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southeast MXT
Mexico Southwest MXS
Nevada NEV
New Mexico NWM
Oklahoma OKL
Oregon ORE
Texas TEX
Utah UTA
Argentina Northeast AGE SOUTHERN AMERICA
Argentina Northwest AGW
Argentina South AGS
Bolivia BOL
Chile Central CLC
Chile North CLN
Ecuador ECU
Galápagos GAL
Paraguay PAR
Peru PER
Uruguay URU

Not drawn on the map: Mexican Pacific Is.. We hold no public-domain boundary for this region, so it is listed rather than guessed at.

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 95 in flower of 109 examined

Proportion of examined Cressa truxillensis in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 2 2 too few examined
Mar 3 4 too few examined
Apr 8 12 67% 39% to 86%
May 16 16 100% 81% to 100%
Jun 24 26 92% 76% to 98%
Jul 22 24 92% 74% to 98%
Aug 7 7 100% 65% to 100%
Sep 3 3 too few examined
Oct 3 5 60% 23% to 88%
Nov 2 3 too few examined
Dec 5 7 71% 36% to 92%

Peak flowering in May. Each bar is the share of Cressa truxillensis 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. 95 of 109 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 5 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 11 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.

  • Cressa arenaria Willd. ex Roem. & Schult.
  • Cressa australis var. petiolata Meisn.
  • Cressa cretica var. truxillensis (Kunth) Choisy
  • Cressa depressa Goodd.
  • Cressa erecta Rydb.
  • Cressa insularis House
  • Cressa minima A.Heller
  • Cressa multiflora Willd. ex Roem. & Schult.
  • Cressa truxillensis var. minima (A.Heller) Munz
  • Cressa truxillensis var. vallicola (A.Heller) Munz
  • Cressa vallicola A.Heller

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.