Disc Cactus (Strombocactus disciformis)

Strombocactus disciformis is listed on CITES Appendix I because it is critically endangered in the wild due to illegal overcollection. This strict international designation prohibits the commercial trade of wild-collected specimens to ensure the species' survival.

Because it originates from limestone outcrops in the Mexican states of Hidalgo and Querétaro, it requires a highly specific soil mix. A substrate heavily amended with crushed limestone or gypsum is essential to mimic its native growing conditions.

Growing this sole species of its genus from seed requires extreme patience, as it is notoriously slow to germinate and mature. Seeds should be sown in a mineral-heavy, limestone-based substrate and kept lightly moist in a warm environment.

A fully mature Strombocactus disciformis remains quite small, rarely exceeding 3 inches in diameter. Its flat, geometric tubercles make it look exactly like a small, disc-shaped rock clinging to cliff faces.