Acaena pinnatifida (Argentinian biddy-biddy)

Plate 1 figs. a–h · 8 separate observations

Acaena pinnatifida, photographed by paulexcoff — fig. a paulexcoff, CC BY-SA 4.0 / 2022-04-10 / obs. 195431407

Acaena pinnatifida, photographed by Cesar Ormazabal — fig. b Cesar Ormazabal, CC BY 4.0 / obs. 168993613

Acaena pinnatifida, photographed by LJ Moore-McClelland — fig. c LJ Moore-McClelland, CC BY 4.0 / obs. 125007049

Acaena pinnatifida, photographed by Henrik Kibak — fig. d Henrik Kibak, CC BY 4.0 / obs. 113166866

Acaena pinnatifida, photographed by Nicolás Villaseca Merino — fig. f Nicolás Villaseca Merino, CC BY-SA 4.0 / obs. 155601736

Acaena pinnatifida, photographed by John Brew — fig. g John Brew, CC BY 4.0 / obs. 31483364

Acaena pinnatifida, photographed by Rudyard — fig. h Rudyard, CC BY 4.0 / obs. 7217705

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 6 botanical countries

Native distribution of Acaena pinnatifida, 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.

Region	TDWG code	Continent
Argentina Northeast	AGE	SOUTHERN AMERICA
Argentina Northwest	AGW
Argentina South	AGS
Chile Central	CLC
Chile South	CLS
California	CAL	NORTHERN AMERICA

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 51 in flower of 127 examined

33%

56%

62%

33%

50%

33%

80%

Proportion of examined Acaena pinnatifida in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	16	6%	1% to 28%
Feb	0	12	0%	0% to 24%
Mar	5	15	33%	15% to 58%
Apr	19	34	56%	39% to 71%
May	13	21	62%	41% to 79%
Jun	3	9	33%	12% to 65%
Jul	0	1	too few examined
Aug	0	0	too few examined
Sep	1	2	too few examined
Oct	3	6	50%	19% to 81%
Nov	2	6	33%	10% to 70%
Dec	4	5	80%	38% to 96%

Peak flowering in Dec. Each bar is the share of Acaena pinnatifida 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. 51 of 127 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 3 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.

Where it actually grows measured, from 390 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-6.7 °C	4.7 °C	8.0 °C
Warmest month, mean daily high	13.0 °C	20.5 °C	28.5 °C
Annual rainfall	500 mm	837 mm	3,381 mm
Rainfall in the driest quarter	6 mm	10 mm	343 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 390 research-grade observations of Acaena pinnatifida 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 67 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.

Acaena aculeata Meyen
Acaena andicola Gillies ex Walp.
Acaena arthrotricha Bitter
Acaena calcitrapa Phil.
Acaena californica Bitter
Acaena californica var. brevifoliolata Bitter
Acaena californica var. grandis Bitter
Acaena californica var. polyarthrotricha Bitter
Acaena californica var. remotiflorens Bitter
Acaena californica var. subglabriscapa Bitter
Acaena euacantha Phil.
Acaena incisa Lindl.
Acaena leptophylla Phil.
Acaena longifolia Phil.
Acaena lucida Willd. ex Steud.
Acaena montana Phil.
Acaena multifida Hook.f.
Acaena multifida subsp. abavia Bitter
Acaena multifida subsp. alaticonnata Bitter
Acaena multifida subsp. canella Bitter
Acaena multifida subsp. intercedens Bitter
Acaena multifida subsp. multiglomerulans Bitter
Acaena multifida subsp. quinquefida Bitter
Acaena multifida var. glaberrima Speg.

and 43 more.

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
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.