Pinguicula gypsicola

Named gypsicola, the gypsum dweller: one of the very few carnivorous plants that grows directly on bare rock. It was first collected from a gypsum quarry northwest of San Luis Potosí in 1910, and its entire known range amounts to just two or three localities in that state. Among agaves, cacti and Dasylirion, it is an unlikely carnivore.

It grows on eroded gypsum hillsides at around 1250 m, wedged into crevices on north-facing slopes. The climate is semi-arid, with almost no rain from November to April. But the gypsum itself acts as a reservoir: moisture stored in the rock evaporates during the heat of the day, then condenses as heavy dew overnight in sheltered crevices. The plant has adapted to harvest this.

Two plants in one. In summer, it produces erect carnivorous leaves up to 13 cm long, covered in sticky glands. When the dry season arrives, it withdraws into a tight succulent rosette of 100 to 170 tiny leaves that look nothing like a Pinguicula. Flowers are purple-violet with a long spur, from June to November.