Ariocarpus retusus
Ariocarpus retusus is a species of cactus, from the genus Ariocarpus, found mainly in Mexico. It is one of the largest and fastest-growing species in this genus known for a slow rate of growth. Despite its slow growth, often taking ten years to reach flowering age, the retusus is a desirable cactus for cultivation, having attractive flowers and an unusual form for a cactus. It is also one of the most easily cultivated species in the genus.
Description
Ariocarpus retusus has flattened, spherical shoots that are gray-green, blue-green, or yellow-green, growing to heights of 3 to 25 centimeters and diameters of 4 to 30 centimeters. The erect, spreading warts protrude from the soil, crowded at the base, and are somewhat pointed or sharp-tipped with rounded or flat tops. The warts measure 1.5 to 4 centimeters long and 1 to 3.5 centimeters wide, sometimes as long as they are wide or twice as long. Occasionally, areoles are present at the tips of the warts. The flowers are cream to light yellow, white, or pinkish red, and have a diameter of 3 to 5 centimeters. The elongated fruits are 1 to 2.5 centimeters long.The chromosome count is 2n = 22.