Porophyllum ruderale(Jacq.) Cass.

yerba porosa

WFO wfo-0000017330 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Porophyllum ruderale, photographed by kbkash
fig. a kbkash, CC0 1.0 / 2022-03-31 / obs. 185627926

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.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
1188473
Filed as
Porophyllum ruderale var. ruderale
Det. by
P. M. Simon 2008-01-01
Collected
H. S. Irwin 1965-12-12
Origin
BR
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 59 botanical countries

Regions where Porophyllum ruderale is native: Algeria, Canary Is., Libya, Madeira, Morocco, Albania, Corse, France, Italy, Portugal, Sicilia, Spain, Arizona, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, New Mexico, Texas, Argentina Northeast, Argentina Northwest, Aruba, Bahamas, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Cayman Is., Chile North, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, French Guiana, Galápagos, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward Is., Netherlands Antilles, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Suriname, Trinidad-Tobago, Uruguay, Venezuela, Venezuelan Antilles, Windward Is. AlgeriaLibyaMoroccoAlbaniaCorseFranceItalyPortugalSiciliaSpainArizonaMexico CentralMexico GulfMexico NortheastMexico NorthwestMexico SoutheastMexico SouthwestNew MexicoTexasArgentina NortheastArgentina NorthwestBoliviaBrazil NorthBrazil NortheastBrazil SouthBrazil SoutheastBrazil West-CentralChile NorthColombiaCosta RicaCubaDominican RepublicEcuadorEl SalvadorFrench GuianaGuatemalaGuyanaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruPuerto RicoSurinameTrinidad-TobagoUruguayVenezuela Canary Is.MadeiraArubaBahamasCayman Is.GalápagosLeeward Is.Netherlands AntillesVenezuelan AntillesWindward Is.
Native distribution of Porophyllum ruderale, 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
Bolivia BOL
Brazil North BZN
Brazil Northeast BZE
Brazil South BZS
Brazil Southeast BZL
Brazil West-Central BZC
Cayman Is. CAY
Chile North CLN
Colombia CLM
Costa Rica COS
Cuba CUB
Dominican Republic DOM
Ecuador ECU
El Salvador ELS
French Guiana FRG
Galápagos GAL
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
Suriname SUR
Trinidad-Tobago TRT
Uruguay URU
Venezuela VEN
Venezuelan Antilles VNA
Windward Is. WIN
Arizona ARI NORTHERN AMERICA
Mexico Central MXC
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southeast MXT
Mexico Southwest MXS
New Mexico NWM
Texas TEX
Albania ALB EUROPE
Corse COR
France FRA
Italy ITA
Portugal POR
Sicilia SIC
Spain SPA
Algeria ALG AFRICA
Canary Is. CNY
Libya LBY
Madeira MDR
Morocco MOR

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 447 in flower of 656 examined

Proportion of examined Porophyllum ruderale in flower, by month
Month In flower Examined Share 95% interval
Jan 19 24 79% 60% to 91%
Feb 21 26 81% 62% to 91%
Mar 43 47 91% 80% to 97%
Apr 87 91 96% 89% to 98%
May 93 100 93% 86% to 97%
Jun 23 28 82% 64% to 92%
Jul 10 37 27% 15% to 43%
Aug 17 74 23% 15% to 34%
Sep 42 84 50% 40% to 60%
Oct 67 88 76% 66% to 84%
Nov 15 38 39% 26% to 55%
Dec 10 19 53% 32% to 73%

Peak flowering in Apr. Each bar is the share of Porophyllum ruderale 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. 447 of 656 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 963 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 2.6 °C 11.7 °C 22.5 °C
Warmest month, mean daily high 23.5 °C 29.5 °C 35.5 °C
Annual rainfall 453 mm 1,000 mm 2,353 mm
Rainfall in the driest quarter 9 mm 92 mm 311 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 963 research-grade observations of Porophyllum ruderale 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 35 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.

  • Anacyclus aureus Brot.
  • Anacyclus aureus var. radiatus Pers.
  • Anacyclus bicolor Pers.
  • Anacyclus pallescens Guss.
  • Anacyclus radiatus Loisel.
  • Anacyclus radiatus var. radiatus
  • Anacyclus radiatus var. sulphureus Braun-Blanq. & Maire
  • Anacyclus valentinus var. bicolor Pers.
  • Anacyclus valentinus var. purpurascens Pers.
  • Anthemis lanuginosa Moench
  • Anthemis purpurascens Nyman
  • Anthemis purpurea Voss
  • Cacalia glandulosa Salisb.
  • Cacalia porophyllum L.
  • Cacalia ruderalis Sw.
  • Kleinia glandulosa Moc. & Sessé
  • Kleinia ruderalis Jacq.
  • Porophyllum ellipticum Cass.
  • Porophyllum ellipticum var. genuinum Urb.
  • Porophyllum ellipticum var. intermedium DC.
  • Porophyllum latifolium Benth.
  • Porophyllum macrocephalum DC.
  • Porophyllum macrocephalum var. macrocephalum
  • Porophyllum porophyllum (L.) Kuntze

and 11 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.