About Gymnocalycium monvillei (Lem.) Pfeiff. ex Britton & Rose
Gymnocalycium monvillei (Lem.) Pfeiff. ex Britton & Rose is a cactus that typically grows individually, and rarely produces new sprouts. Its shoots are dark green, shaped from spherical to flattened spherical, and reach 6 to 8 centimeters in height and up to 20 centimeters in diameter. This species forms a massive taproot, and older plants sometimes become shorter and take on a more columnar shape. It has 10 to 17 wide, blunt ribs that are clearly divided into humps with noticeable chin-like projections. The areoles are oval, and contain dirty-whitish wool felt in addition to spines. The strong, thick, slightly curved spines are yellowish with reddish or purple bases. There are one to four central spines that grow up to 6 centimeters long, and central spines are sometimes absent entirely. Marginal spines number 7 to 13, and measure 3 to 4 centimeters long. The flowers are white with a red tinge, partially monoecious, and reach 3 to 8 centimeters in length and 4 to 9 centimeters in diameter. The stamens are whitish with yellowish pollen, and the style is whitish yellow. The spherical fruits are green to cloudy orange-red, and grow up to 2 centimeters in diameter. Gymnocalycium monvillei is distributed in central and northern Argentina, specifically in the provinces of Córdoba and San Luis, growing at altitudes between 500 and 2700 meters.
