Melocactus macracanthos

Plate 1 figs. a–h · 8 separate observations

Melocactus macracanthos, photographed by Keith Seifert — fig. b Keith Seifert, CC BY-SA 4.0 / obs. 60497350

Melocactus macracanthos, photographed by Eric Knight — fig. c Eric Knight, CC BY 4.0 / obs. 47396019

Melocactus macracanthos, photographed by Paul Asman — fig. f Paul Asman, CC BY 4.0 / obs. 170231185

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: Royal Botanic Gardens, Kew
Accession: K000101901
Filed as: Melocactus macracanthos (Salm-Dyck) Link & Otto
Det. by: not recorded on this sheet
Collected: Rodgers; Evans
Origin: not recorded
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 2 botanical countries

Native distribution of Melocactus macracanthos, 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
Aruba	ARU	SOUTHERN AMERICA
Netherlands Antilles	NLA

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.

Where it actually grows measured, from 425 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	24.6 °C	25.0 °C	25.1 °C
Warmest month, mean daily high	27.7 °C	28.2 °C	28.2 °C
Annual rainfall	512 mm	617 mm	721 mm
Rainfall in the driest quarter	51 mm	63 mm	73 mm

It is not found anywhere that gets close to freezing. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 425 research-grade observations of Melocactus macracanthos 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.

Also published as 131 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.

Cactus macracanthos Salm-Dyck
Cactus macracanthus Salm-Dyck
Cactus microcephalus (Miq.) Borg
Cactus parvispinus Haw.
Cactus pyramidalis Salm-Dyck
Cactus zuccarinii (Miq.) Borg
Echinocactus armatus Salm-Dyck
Echinocactus fischeri Pfeiff.
Echinocactus parvispinus (Haw.) DC.
Echinocactus salmianus Link & Otto
Echinocactus spina-christi Zucc. ex Pfeiff.
Melocactus aciculosus Valck.Sur.
Melocactus aciculosus var. adauctus Valck.Sur.
Melocactus albispinus Suringar
Melocactus albispinus f. quadrispina Suringar
Melocactus angusticostatus Suringar
Melocactus appropinquatus Valck.Sur.
Melocactus approximatus Suringar
Melocactus arcuatus Suringar
Melocactus argenteus Suringar
Melocactus argenteus var. tenuispina Suringar
Melocactus armatus Suringar
Melocactus baarscanus Suringar
Melocactus baarsianus Suringar

and 107 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.
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.