These plants can be described as powerful, for they have exceptionally strong, heavy spines, and the name is suggestive of the ferocity of these weapons of defence. The are round or cylindrical. As a rule the areoles are large and the are produced on the young areoles immediately above the of spines. They are mostly yellow or red. The genus includes about 32 species.
Ferocactus acanthodes. S. California. Theof this plant generally grows singly, and with age can attain a height of about 9 feet and reach 1 foot in diameter. Radial spines number 9 to 13, centrals 4. The are shades of yellow and orange. Grows well in cultivation, particularly in sunny exposures, and is a desirable species.
Ferocactus Wislizenii. Texas and Arizona. When young the stem is globular, becoming cylindrical with age. It is a very fine plant, growing to a height of 7 feet. Ribs number 15 to 25. The areoles are large and oval, and at first bear yellowish wool, which turns brown or grey; radial spines number about 20, centrals 4, the latter very thick and strongly hooked at the tip. The flowers have a green tube, with the outer petals green, the inner petals reddish-yellow. Grows well in cultivation, requiring sunshine and warmth and a rich porous soil to which has been added some gravel, chippings or crushed bricks, and a small quantity of old mortar rubble.
Ferocactus Pringlei. Mexico. One of the largest species of Ferocactus. Individual plants in the wild may reach a height of 9 to 10 feet with a diameter of 12 to 16 inches. Possesses 16 to 18 ribs with numerous closely set areoles, the outer edges of which show a row of long yellow or straw-coloured hairs or bristles, with a few needle-shaped spines. There is 1 central spine, which is the strongest and is somewhat flattened and generally curved, though sometimes practically straight. The species has red flowers, with yellow inside. It is a desirable plant when young, and should be included in all collections.
Ferocactus latispinus. Mexico. Perhaps one of the best known of the genus. It has 8 to 14 ribs when young, and 21 ribs when old. Radial spines number 6 to 10, central spines 4. The flowers are normally pink or purplish-red, but frequently shades of mauve and deep violet-blue.