Mammillaria pilcayensis - Cactus

Mammillaria pilcayensis, often found under the spelling Mammillaria plicayensis, is a small columnar cactus prized for its very dense prickles and its pretty crown of purplish pink flowers. It will thrive on a very bright windowsill, in a lightly heated conservatory in winter, or in a greenhouse. This botanical species will delight cactus collectors and succulent enthusiasts looking for a reliable, architectural, and compact species.

Belonging to the Cactaceae family, this plant is now attached to Mammillaria spinosissima as a synonym or subspecies according to botanical sources. The name Mammillaria pilcayensis, published in the late 1950s, refers to a plant native to Mexico, more specifically the state of Guerrero, where it grows in barrancas and dry rocky areas between 600 and 1,500 m altitude. In the wild, it grows in open, hot, well-drained environments, subject to strong light and a long dry season.
The plant develops a cylindrical, dark blue-green stem, solitary or sparingly branched at the base, reaching 30 to 50 cm in length and 4 to 5 cm in diameter. With age, it tends to elongate and then lean slightly. The conical to cylindric-conical tubercles on its epidermis are arranged in tight spirals. Their axils bear a little wool and fine bristles. Each tubercle has 30 to 34 very fine prickles, radial and central with little differentiation, greyish white to pale yellow with brownish tips, measuring 5 to 6 mm. The purplish pink to purple flowers are about 2 cm in diameter and gathered in a crown near the top of the stem. 

Indoors, this mammillaria requires very bright light, a few hours of direct, not too scorching sun, air humidity between 30 and 50% and temperatures between 18 and 30 °C during the growing season, and a cooler, dry winter rest around 8 to 12 °C. It is easy to grow, even for a beginner, provided you avoid excess moisture and lack of light; it thrives particularly in a bright conservatory, behind a well-exposed bay window, or in a very bright room.

This Mammillaria will greatly benefit from being outdoors from spring to autumn, exposed to the sun and sheltered from excessive rain. Bring it before the first frosts to overwinter in a bright, dry, cool place, protected from frost.

This cactus will fit into a small collection or can be used as a specimen plant in a terracotta pot, where its silhouette and flowers can be observed up close. To create a display, group it with the Jade plant Crassula ovata, Haworthia ‘Big Band’ and Gasteria ‘D. Nella’, as well as Echeveria agavoides 'Ebony'.