Mammillaria vetula is a small, globular cactus species in the Mammillaria genus, known for its compact size and dense covering of spines. This cactus is native to Mexico and is a popular choice among cactus enthusiasts due to its attractive appearance and ease of care. There are several subspecies and varieties of Mammillaria vetula, each with slightly different characteristics, but all share the same basic care requirements.

Key Characteristics:

• Shape: Mammillaria vetula typically forms a small, spherical or cylindrical stem that can grow to about 2-4 inches (5-10 cm) in diameter and 3-6 inches (7-15 cm) in height. The stem is covered in tubercles (small, rounded projections) rather than ribs, which is characteristic of Mammillaria species.
• Spines: The tubercles of Mammillaria vetula are densely packed with spines. These spines can be white, yellow, or brown and often create a woolly or hairy appearance on the surface of the cactus. Some varieties may have a central spine that is longer and more prominent.
• Flowers: In spring and summer, Mammillaria vetula produces small, funnel-shaped flowers that typically form a ring or crown around the top of the cactus. The flowers can be white, yellow, pink, or red, depending on the variety.
• Fruits: After flowering, the cactus may produce small, red or pink fruits that are often elongated and add to its ornamental appeal.

Care Tips for Mammillaria vetula:

1. Light:
   • Mammillaria vetula thrives in bright, indirect light. It can tolerate some direct sunlight, especially in the morning or late afternoon, but too much intense midday sun can cause the cactus to become scorched. If growing indoors, place it near a sunny window with plenty of light.
2. Watering:
   • Water the cactus sparingly, allowing the soil to dry out completely between waterings. Use the “soak and dry” method: water thoroughly and let any excess water drain away. Overwatering can lead to root rot, which is a common issue with cacti. During the winter months, when the cactus is dormant, reduce watering to prevent moisture-related problems.
3. Soil:
   • Use a well-draining cactus or succulent soil mix. Adding perlite, pumice, or coarse sand to the soil can improve drainage and prevent water from pooling around the roots.
4. Temperature:
   • Mammillaria vetula prefers warm temperatures during the growing season, ideally between 70-85°F (21-29°C). It can tolerate cooler temperatures down to about 50°F (10°C) but should be protected from frost. If grown outdoors, it can be brought inside during the winter months if necessary.
5. Fertilizing:
   • Fertilize the cactus once a month during the growing season (spring and summer) with a diluted, balanced cactus fertilizer. Avoid fertilizing during the winter when the plant is dormant.
6. Propagation:
   • Mammillaria vetula can be propagated by offsets (pups) that form around the base of the plant. These offsets can be removed and planted in their own pots. Allow the offsets to callous over for a few days before planting them in well-draining soil. The cactus can also be grown from seeds, though this method is slower.
7. Pests and Diseases:
   • This cactus is generally resistant to pests but may occasionally attract mealybugs or spider mites. Regular inspection and prompt treatment with insecticidal soap or neem oil can help prevent infestations. Be mindful of root rot, which can occur if the cactus is overwatered or the soil does not drain well.