Echinocactus grusonii
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 meter 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.
While easy to grow, these plants do have some basic requirements; an average minimum, winter temperature of 12°C, 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.
