Echinocactus grusonii

Native to central Mexico, in the Rio Moctezuma Valley, Querétaro. Rare and endangered in the wild - the small population in Querétaro occurs on medium to steep slopes of volcanic rock in a very small area (less than 10 km²). The total number of plants in the Querétaro population is estimated to be less than 1,000, the majority of which are mature.

A new sub-population was discovered in Zacatecas growing in semi-desert matorral (shrubland), among volcanic rocks.

Despite the fact that few plants remain in the wild today, their off-site conservation has allowed for extensive propagation by nurseries, and the golden barrel cactus is now one of the most common cacti in cultivation.

Growing as a large roughly spherical globe, Echinocactus grusonii may eventually reach over 1 m in height after many years. The specimen in the top right of this grouping is 45 cm diameter.