Frailea castanea

Scientific Name

Frailea castanea Backeb.

Synonym(s)

Astrophytum castaneum

Scientific Classification

Family: Cactaceae
Subfamily: Cactoideae
Tribe: Notocacteae
Genus: Frailea

Etymology

The specific epithet "castanea" (pronounced "kas-TAN-nee-uh") means "chestnut tree, chestnut (nut)" and most likely refers to the chestnut-like color of the stems of this species.

Origin

Frailea castanea is native to southern Brazil (Rio Grande do Sul), northern Uruguay, and northeastern Argentina. It grows on rocky outcrops at elevations that range from 490 to 980 feet (150 to 300 m).

Description

Frailea castanea is a fascinating small cactus with a typically solitary, spherical, and apically strongly depressed stem with 8 to 15 distinct ribs lined with areoles that bear dark hair and clusters of very short spines. The stem is dark reddish-green to chocolate brown and can grow up to 2 inches (5 cm) in diameter. Each areole bears 3 to 15 reddish to almost black spines.

The flowers are pale yellow, often larger than the stem, and appear in summer. They can reach a diameter of 1.6 inches (4 cm). Midafternoon is when you are most likely to find the flowers open.

How to Grow and Care for Frailea castanea

Hardiness: USDA hardiness zones 10a to 11b: from 30°F (-1.1°C) to 50°F (10°C).

Frailea cacti perform best in full sun, but be cautious about placing them too close to a southern window where the flesh can burn. The tone of the cactus is darkest when it enjoys a full day of sunlight.

This short-lived plant rarely exceeds 15 years before it dies back. Here is a fun fact about Frailea. If plants are growing in areas where no water is available, they can survive by hiding in the soil. Don't be surprised if your plant appears to have disappeared, as it is retracted under the soil, just as it would in the dry season in its native region. Once sufficient moisture is available, the plant swells and becomes visible again on the surface of the soil.

Caring for Frailea is a balancing act between sufficient moisture and periods of soil drying, so water is the biggest challenge in Frailea cactus care. Choose water that is free from heavy minerals. Water well once per week in summer, but water only once every three weeks or when the soil is quite dry to the touch in spring and fall. The plant experiences no growth in winter and does not need water.

Learn more at How to Grow and Care for Frailea.