Thelocactus rinconensis
Family: Cactaceae​
​Common Name: bird's-nest cactus
​Origin: Thelocactus rinconensis is found in Coahuila and Nuevo Leon, Mexico. It occupies the xerophytic shrublands of the Chihuahuan desert, at altitudes of 1,200 to 1,900 meters above sea level.
Description: The bird’s-nest cactus is a solitary to clumping species that possesses a squat and highly ribbed stem with a flattened head. The stems are either light-glaucous in color or green tinged with purple, with numerous tubercles tipped with varied spines. Mature plants 5 to 9 years old may develop white or pink flowers, with yellow at the base of petals. Flowers will bloom in bursts beginning in mid-March or April, and ending in mid-September.
  • Interesting Features:
    • Thelocactus rinconensis is the largest of the Thelocactus genus, and is a highly varied species. Plants differ in size, stem color, and spine color, bearing dark-brown, silver, grey, or yellow spines.
    • Additionally, older plants may develop spines with a "shredded" appearance.
  • Uses: T. rinconensis can be planted in xeriscape and desert gardens, or kept indoors as a container plant. However, aside from its value in cultivation, there are no recorded ethnobotanical uses for the bird’s-nest cactus.

Cultivation and Care:
  • Watering: Moderate
    • Provide low to moderate watering during March to October, irrigating when the soil is completely dry.
    • Do not water during winter, and protect from high atmospheric humidity.
  • ​Soil: Plant Thelocactus rinconensis in a permeable, well-draining soil with little organic matter, avoiding peat and humus.
    • Additionally, maintain a pH between 6.1 and 7.8 for proper growth.
  • Lighting: During the winter months, it is crucial to provide the bird’s-nest cactus with full sun. However, partial shade is required in the summer, with morning sun and afternoon protection.
    • Plants grown in shade will develop darker and richer coloring than those exposed to bright light.
  • Propagation: While it is possible for T. rinconensis to produce offsets, the occurrence is rare, and propagation is normally done through seed.
    • Sow seed directly after the last frost, or plant indoors, in vented containers.
  • Cold Tolerance: 20°F, USDA hardiness zones 9a to 11.
  • Special Accommodations: Move to a cool location during the winter months, and protect from moisture, to allow for a winter resting period.
    • Additionally, feed with a low-nitrogen content fertilizer during spring and summer, and repot every 2 years to encourage growth.
    • Always wear gloves when handling, to avoid damage by the sharp spines.

Sources:​​
  1. Llifle Encyclopedia of Succulents
  2. Ruth Bancroft Garden & Nursery
  3. Starr Nursery
  4. Cactus Art Nursery
  5. Plant Lust
  6. Dave’s Garden