Echinocactus grusonii

Echinocactus grusonii
Echinocactus grusonii in a cactus collection
Conservation status
Critically Endangered (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Caryophyllales
Family:	Cactaceae
Subfamily:	Cactaceae
Tribe:	Cacteae
Genus:	Echinocactus
Species:	E. grusonii
Binomial name
Echinocactus grusonii Hildm.

Echinocactus grusonii is a well known species of cactus native to central Mexico from San Luis Potosi to Hidalgo. Described by Heinrich Hildmann in 1891, it is popularly known as the Golden Barrel Cactus, Golden Ball or, amusingly, Mother-in-Law's Cushion. It belongs to the small genus Echinocactus, which together with the related genus Ferocactus, are commonly referred to as barrel cacti.

Despite being one of the most popular cacti in cultivation, it is rare and critically endangered in the wild.

Growing as a large roughly spherical globe, it may eventually reach over a metre in height after many years. 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. Note: Younger Golden Barrels do not look similar to the mature ones. 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.

Cultivation

Widely cultivated in warmer climates around the world, it is considered easy to grow and relatively fast growing. It has been increasingly used as an architectural plant in garden design. Jamie Durie, one of Australia's leading garden designers, has called it one of his personal favourite plants. A white-spined form is also in cultivation, as is a short-spined form.

While easy to grow, these plants do have some basic requirements; an average minimum winter temperature of 12°C (53.6ºF), good drainage with less watering in winter. Excess water in cool periods may lead to rot. Golden Barrels are hardy to about 15ºF (-8ºC) for brief periods.

Outside Mexico, Echinocactus grusonii specimens may be seen in collections of desert plants in many botanical gardens.

Gallery

• 

  Mature Golden Barrels showing their distinctive clustering habit. Photo from the Huntington Desert Garden in California.

• 

  Echinocactus grusonii Hildm, photo is taken at Bedugul Botanical Garden, Bali, Indonesia

• 

  Echinocactus grusonii, spineless form

• 

  Flower detail

• 

  Echinocactus grusonii spine detail at the United States Botanic Gardens

• 

  Stereoscopic crossview of a Golden Barrel Cactus.

References

• Fitz Maurice, W. A. & Fitz Maurice, B. (2002). Echinocactus grusonii. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 4 November 2006.
• Preston-Mafham, Rod & Ken (1992). Cacti: The Illustrated Dictionary. Blandford Press. ISBN 978-0-7137-2092-1.