Echinocactus grusonii

Echinocactus grusonii belongs to the small genus Echinocactus, which together with the related genus Ferocactus, are commonly referred to as barrel cacti. The species was first described by German plantsman Heinrich Hildmann in 1891. While sometimes referred to as golden ball, this species is not to be confused with Notocactus leninghausii which have fuzzy, harmless spines and are native to Brazil and Paraguay.

Growing as a large roughly spherical globe, Echinocactus grusonii may eventually reach over 1 metre (3.3 ft) in height after many years. Younger Golden Barrel plants do not look similar to mature specimens. The generation lifetime is estimated to be 30 years.[1]

There may be up to 35 pronounced ribs in mature plants, though they are not evident in young plants, which may have a knobbly appearance. The sharp spines are long, straight or slightly curved, and various shades of yellow or, occasionally, white.

Small yellow flowers appear in summer around the crown of the plant, but only after twenty years or so.

Golden barrel cacti at the Huntington

Echinocactus grusonii is widely cultivated by specialty plant nurseries as an ornamental plant, for planting in containers, desert habitat gardens, rock gardens, and in conservatories.[2] A white-spined form, and a short-spined form, are also in cultivation.

It is one of the most popular cacti in cultivation and has increasingly become popular as an architectural accent plant in contemporary garden designs.

The cactus is considered easy and relatively fast growing in warmer climates around the world. The plants do have some basic requirements; an average minimum winter temperature of 12 °C (53.6 °F); and good drainage with less watering in winter.[2] Excess water in cool periods may lead to rot. Golden Barrels are hardy to about −8 °C (15 °F) for brief periods.

Beyond Central Mexico, Echinocactus grusonii specimens may also be seen in collections of desert plants in many botanical gardens. In the UK it has gained the Royal Horticultural Society’s Award of Garden Merit.[3][4]

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  Mature golden barrels showing their distinctive clustering habit. Photo from the Huntington Desert Garden in California.
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  Closeup of the top.
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  Echinocactus grusonii, a nearly spineless form
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  Echinocactus grusonii spine detail at the United States Botanic Gardens
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  Stereoscopic crossview of a golden barrel cactus.
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  Spine detail
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  Flower detail
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  Fruit detail
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  Seeds

• Cacti of Mexico

• Fitz Maurice, W. A. & Fitz Maurice, B. (2002). "Echinocactus grusonii". IUCN Red List of Threatened Species. 2002. Retrieved 4 November 2006.CS1 maint: ref=harv (link)old-form url
• Preston-Mafham, Rod & Ken (1992). Cacti: The Illustrated Dictionary. Blandford Press. ISBN 978-0-7137-2092-1.

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