Tephrocactus articulatus, commonly known as Pine Cone Cactus, is a unique, slow-growing cactus native to northern Argentina. Cactus collectors widely love it for its distinct, pinecone-shaped stem segments that stack atop one another. This species is probably the most variable in the genus, resulting in an excess of scientific names.
Taxonomy of Tephrocactus articulatus
Scientific Name
Tephrocactus articulatus (Otto) Backeb.
Synonym(s)
Cereus articulatus, Opuntia articulata
Common Name(s)
Pine Cone Cactus, Spruce Cone Cholla
Scientific Classification
Family: Cactaceae
Subfamily: Opuntioideae
Tribe: Tephrocacteae
Genus: Tephrocactus
Etymology
The specific epithet "articulatus" (pronounced "ar-tik-oo-LAH-tus") means "articulated; jointed" and refers to the appearance of the attachment points of the stem segments of this species.
Description
Tephrocactus articulatus is a small cactus with erect, loosely branching stems composed of pinecone-shaped, green to gray-green segments. It can grow up to 12 inches (30 cm) tall, eventually forming an upright shrub. The stem segments are ovoid to short-cylindrical, prominently tuberculate, usually tenuously attached, and easily dislodged. They can reach a length of 4 inches (10 cm) and a diameter of up to 1.6 inches (4 cm), but are typically 1.2 to 2 inches (3 to 5 cm) long and of similar diameter. The tubercles are spirally arranged and tipped with small, almost round, woolly areoles that bear red to purplish black glochids and sometimes 1 to 4 flattened, flexible spines.
In the spring, Tephrocactus articulatus produces beautiful white to light pink flowers with pericarpels covered with spineless areoles. The flowers can measure up to 1.8 inches (4.5 cm) in length. The fruits are brown, depressed, and spherical, and can grow up to 0.9 inches (2.2 cm) long and 0.9 inches (2.2 cm) in diameter.
Origin
Tephrocactus articulatus is native to northern Argentina. It occurs in Catamarca, Córdoba, La Rioja, Mendoza, Salta, San Luis, and Santiago del Estero.
Forms of Tephrocactus articulatus
- Tephrocactus articulatus var. diadematus (not accepted as a separate variety and is treated as a synonym of Tephrocactus articulatus)
- Tephrocactus articulatus var. inermis (not accepted as a separate variety and is treated as a synonym of Tephrocactus articulatus)
- Tephrocactus articulatus var. papyracanthus (not accepted as a separate variety and is treated as a synonym of Tephrocactus articulatus)
How to Grow and Care for Tephrocactus articulatus
Light: Tephrocactus articulatus thrives in full sun, but some midday and afternoon shade can prevent sunburn in hot climates. When grown indoors, a window that receives 6 hours of sunlight a day works best.
Soil: This cactus requires a well-draining potting mix. You can use a commercial cactus potting mix or create your own.
Temperature: Extremely tolerant of high temperatures, Tephrocactus articulatus prefers cooler temperatures in winter. It grows best in USDA Plant Hardiness Zones 8b to 10b, with average minimum winter temperatures ranging from 15°F to 40°F (-9.4°C to 4.4°C).
Watering: From spring to fall, water moderately and allow the soil to dry out completely before watering again. In most areas, rainfall will be enough for established plants. If potted, never let the container sit in water. During the winter, suspend the watering.
Fertilizing: Tephrocactus articulatus does not need fertilizer when planted in the ground. However, if grown in a container, it will benefit from fertilizer during the growing season. Apply a water-soluble fertilizer. Suspend feeding during the winter when the plant goes dormant.
Repotting: Repot only when the cactus becomes potbound or is too large and unstable in its container. Choose a slightly larger container with drainage holes at the bottom. The best time for repotting is late winter or early spring.
Propagation: You can propagate Tephrocactus articulatus by stem segments or seeds. Using stem segments is the easiest method and yields faster results. For best results, take stem segments in early summer. Sow the seeds in late spring.
Learn more in "How to Grow and Care for Opuntia."
Toxicity of Tephrocactus articulatus
Tephrocactus articulatus is not toxic to humans or pets. However, it is best to keep it away from pets and children, as its glochids may cause skin irritation.
Photo Gallery
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Internal Links
- Explore all plants within the genus Tephrocactus.
- Explore all plants within the family Cactaceae.