Cyclospermum leptophyllum(Pers.) Sprague

marsh parsley

WFO wfo-0001069061 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Cyclospermum leptophyllum, photographed by ahaislip
fig. a ahaislip, CC0 1.0 / 2022-05-03 / obs. 194438849

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 28 botanical countries

Regions where Cyclospermum leptophyllum is native: Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southeast, Mexico Southwest, Argentina Northeast, Argentina Northwest, Argentina South, Bolivia, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Chile Central, Chile North, Chile South, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Nicaragua, Panamá, Paraguay, Peru, Uruguay, Venezuela Mexico CentralMexico GulfMexico NortheastMexico SoutheastMexico SouthwestArgentina NortheastArgentina NorthwestArgentina SouthBoliviaBrazil NortheastBrazil SouthBrazil SoutheastBrazil West-CentralChile CentralChile NorthChile SouthColombiaCosta RicaEcuadorEl SalvadorGuatemalaHondurasNicaraguaPanamáParaguayPeruUruguayVenezuela
Native distribution of Cyclospermum leptophyllum, 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
Argentina South AGS
Bolivia BOL
Brazil Northeast BZE
Brazil South BZS
Brazil Southeast BZL
Brazil West-Central BZC
Chile Central CLC
Chile North CLN
Chile South CLS
Colombia CLM
Costa Rica COS
Ecuador ECU
El Salvador ELS
Guatemala GUA
Honduras HON
Nicaragua NIC
Panamá PAN
Paraguay PAR
Peru PER
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 279 in flower of 355 examined

Proportion of examined Cyclospermum leptophyllum in flower, by month
Month In flower Examined Share 95% interval
Jan 26 37 70% 54% to 83%
Feb 15 19 79% 57% to 91%
Mar 27 32 84% 68% to 93%
Apr 34 43 79% 65% to 89%
May 28 35 80% 64% to 90%
Jun 24 34 71% 54% to 83%
Jul 19 24 79% 60% to 91%
Aug 25 30 83% 66% to 93%
Sep 23 25 92% 75% to 98%
Oct 27 35 77% 61% to 88%
Nov 18 21 86% 65% to 95%
Dec 13 20 65% 43% to 82%

Peak flowering in Sep. Each bar is the share of Cyclospermum leptophyllum 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. 279 of 355 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 1,966 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 1.2 °C 7.0 °C 14.7 °C
Warmest month, mean daily high 22.8 °C 28.8 °C 34.9 °C
Annual rainfall 310 mm 955 mm 2,025 mm
Rainfall in the driest quarter 4 mm 154 mm 294 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 1,966 research-grade observations of Cyclospermum leptophyllum 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 36 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.

  • Aethusa leptophylla (Pers.) Spreng.
  • Apium ammi f. filamentosum (Kuntze) H.Wolff
  • Apium ammi f. latisectum (Urb. & H.Wolff)
  • Apium ammi f. nanum Kuntze
  • Apium ammi f. pedunculata Chodat
  • Apium ammi var. caespitosum Urb.
  • Apium ammi var. filamentosum Kuntze
  • Apium ammi var. genuinum H.Wolff
  • Apium ammi var. latisectum Urb.
  • Apium ammi var. leptophyllum (DC.) Kuntze
  • Apium andinum H.Wolff
  • Apium depressum M.E.Jones
  • Apium laciniatum f. elatius H.Wolff
  • Apium leptophyllum (Pers.) F.Muell.
  • Apium leptophyllum var. dubium Domin
  • Apium leptophyllum var. latisectum (Urb.) Mathias & Constance
  • Apium leptophyllum var. multisectum Mathias & Constance
  • Apium rivulare Larrañaga
  • Apium tenuifolium (Moench) Thell.
  • Apium wolffianum M.Hiroe
  • Cnidium tenuifolium Moench
  • Cyclospermum ammi (Savi) Caruel
  • Cyclospermum tenuifolium (Moench) Thell.
  • Helosciadium heterophyllum Steud.

and 12 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. USDA PLANTS Database. common name, checklist symbol CYLE7. 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.