Echinocactus is a genus of 6 species in the Cactaceae family native to south western United States and Mexico. The generic name comes from the Greek word echinos, meaning ‘spiny’, and cactus. Together with Ferocactus, they are the two genera of barrel cactus. The species in this genus have some noticeably distinguishable features, such as large spines, well defined ribs, an overall barrel shape with relatively small, yellow or pink flowers being borne out of an area at the apex of the plant that is covered in a dense fuzzy wool, followed by woolly, fleshy or dry fruits. Propagation is by seed. The most well-known, easily grown and widely cultivated species, Echinocactus grusonii, or Golden Barrel cactus, is nearly extinct in the wild and only occurs in a very small area, which contrasts from the rest of the genus in that the rest of the genus are more widespread and less common in cultivation. Echinocactus polycephalus for example, is notoriously difficult to grow. Echinocactus species can be grown as pot plants and make interesting features on a sunny veranda. They also make an attractive addition to a rockery or water-wise garden.

Echinocactus ingens, Syn. Echinocactus platyacanthus is a species of cactus native to southern and central Mexico. The name platyacanthus comes from the Greek word platys meaning ‘wide’. Spanish common names include “Biznaga de Dulce” and “Biznaga Gigante”. The largest of the barrel cacti, this species can grow as big as 2. 5 meters high and up to 80 cm in diameter. Their growth pattern starts of spherical, and as the get older grow into barrel shaped plants. The plants are green to yellowish green in colour with 5 up to 60 or more well defined ribs with large black spines. Younger plants look slightly different with a sometimes grey green colour and yellowish to red spines. Mature plants bear numerous yellow flowers in the fluffy crown which later form oblong fruits covered in scales. Cultivation is done from seed. They should be watered very sparingly in winter and must not be allowed to sit in wet soil, otherwise they will rot. As with most cacti they require a well drained sandy soil to grow in.