Scientific Name
Opuntia robusta H. L. Wendl. ex Pfeiff.
Common Name(s)
Wheel Cactus, Giant Prickly Pear Cactus, Wheel Pear, Silver Dollar, Silver Dollar Cactus, Silver Dollar Prickly Pear, Dinner Plate Cactus, Sweet Purple Cactus
Synonym(s)
Opuntia camuessa, Opuntia gorda, Opuntia guerrana, Opuntia larreyi
Scientific Classification
Family: Cactaceae
Subfamily: Opuntioideae
Tribe: Opuntieae
Genus: Opuntia
Etymology
The specific epithet "robusta" (pronounced "roh-BUS-tuh") means "hard, firm, solid, robust" and refers to the general appearance of this species.
Origin
Opuntia robusta is native and endemic to Mexico.
Description
Opuntia robusta is a shrubby or tree-like cactus with much-branched stems consisting of flattened, blue-green to blue-grey segments with areoles that bear tufts of numerous glochids and 2 to 12 sharp spines. It can grow up to 15 feet (4.5 m) tall and nearly equal in width. The stem segments are thick, fleshy, round, flattened, and can measure up to 16 inches (40 cm) in diameter. The spines can grow up to 2 inches (5 cm) long.
The yellow, bowl-shaped flowers can reach a length of 2.8 inches (7 cm) and a diameter of 3.2 inches (8 cm). They appear at the edges of the upper stem segments in late spring and summer. The fleshy, barrel-shaped, pink or purple fruits can grow up to 3.6 inches (9 cm) long.
Hardiness
USDA hardiness zones 9a to 11b: from 20°F (-6.7°C) to 50°F (10°C).
How to Grow and Care
Though the large variety of species within the Opuntia genus means different types of Prickly Pears may need slightly different care. All are desert cacti that require lots of sun, lots of light, and very little water. If you live in a hot, arid area, these plants can generally be planted outside, left alone, and enjoyed.
These cacti will grow just fine in a garden, but can also be grown in pots. To repot, ensure the soil is dry, remove the pot, and remove the old soil. After treating any cuts with fungicide, place the cactus in a new pot and backfill it with potting soil. As with a new cutting, do not water a newly repotted Prickly Pear for a brief period to avoid rotting its roots.
Opuntia can be propagated either by cuttings or by seed. To propagate by cuttings, sever pads from a plant and let them dry so the wounds heal. Then, place the plants in dry soil and refrain from watering them until they begin to grow to avoid rotting them.
Learn more at How to Grow and Care for Opuntia.
Links
- Back to genus Opuntia
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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