Centaurea sphaerocephala

Plate 1 figs. a–h · 8 separate observations

Centaurea sphaerocephala, photographed by Chiara Catalano — fig. b Chiara Catalano, CC BY-SA 4.0 / obs. 141263396

Centaurea sphaerocephala, photographed by Ira Gershenhorn — fig. c Ira Gershenhorn, CC0 1.0 / obs. 38560757

Centaurea sphaerocephala, photographed by Duarte Frade — fig. d Duarte Frade, CC BY 4.0 / obs. 36537074

Centaurea sphaerocephala, photographed by jfgodeau — fig. e jfgodeau, CC BY-SA 4.0 / obs. 61919905

Centaurea sphaerocephala, photographed by Riccardo Rocca — fig. g Riccardo Rocca, CC BY 4.0 / obs. 197513759

Centaurea sphaerocephala, photographed by Andrea Meucci — fig. h Andrea Meucci, CC BY-SA 4.0 / obs. 129777533

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 11 botanical countries

Native distribution of Centaurea sphaerocephala, 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.

Region	TDWG code	Continent
Corse	COR	EUROPE
Italy	ITA
Portugal	POR
Sardegna	SAR
Sicilia	SIC
Spain	SPA
Algeria	ALG	AFRICA
Libya	LBY
Madeira	MDR
Morocco	MOR
Tunisia	TUN

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 261 in flower of 274 examined

100%

96%

93%

97%

78%

100%

Proportion of examined Centaurea sphaerocephala in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	3	3	too few examined
Feb	9	9	100%	70% to 100%
Mar	45	47	96%	86% to 99%
Apr	76	82	93%	85% to 97%
May	76	78	97%	91% to 99%
Jun	28	29	97%	83% to 99%
Jul	7	9	78%	45% to 94%
Aug	3	3	too few examined
Sep	2	2	too few examined
Oct	5	5	100%	57% to 100%
Nov	3	3	too few examined
Dec	4	4	too few examined

Peak flowering in Feb. Each bar is the share of Centaurea sphaerocephala 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. 261 of 274 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.

Where it actually grows measured, from 177 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	6.2 °C	8.3 °C	11.4 °C
Warmest month, mean daily high	25.6 °C	27.8 °C	32.1 °C
Annual rainfall	477 mm	653 mm	908 mm
Rainfall in the driest quarter	15 mm	30 mm	87 mm

It is barely found anywhere that freezes. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 177 research-grade observations of Centaurea sphaerocephala 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 22 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.

Calcitrapoides lusitanica (Boiss. & Reut.) Holub
Calcitrapoides malacitana (Boiss.) Holub
Calcitrapoides polyacantha (Willd.) Holub
Calcitrapoides sphaerocephala (L.) Holub
Centaurea caespitosa Cirillo
Centaurea corsica Gand.
Centaurea fontanesii Spach ex Durieu
Centaurea ixodes Pomel
Centaurea linnaeana Walp.
Centaurea lusitanica Boiss. & Reut.
Centaurea malacitana Boiss.
Centaurea polyacantha Willd.
Centaurea polyacantha var. adpressa Maire
Centaurea polyacantha var. polyacantha
Centaurea pterocaulos Pomel
Centaurea sonchifolia subsp. malacitana (Boiss.) Nyman
Centaurea sphaerocephala J.Gav ex Durieu
Centaurea sphaerocephala var. fontanesii (Durieu) Batt.
Centaurea sphaerocephala var. oligocentra Maire
Centaurea sphaerocephala var. polyacantha (Willd.) Rivas Mart.
Centaurea sphaerocephala var. sphaerocephala
Centaurea sphaerocephala var. transiens Faure & Maire

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.
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.