Scientific Name
Opuntia robusta H. L. Wendl. ex Pfeiff.
Common Names
Wheel Cactus, Giant Prickly Pear Cactus, Wheel Pear, Silver Dollar, Silver Dollar Cactus, Silver Dollar Prickly Pear, Dinner Plate Cactus, Sweet Purple Cactus
Synonyms
Opuntia camuessa, Opuntia gorda, Opuntia guerrana, Opuntia larreyi
Scientific Classification
Family: Cactaceae
Subfamily: Opuntioideae
Tribe: Opuntieae
Genus: Opuntia
Description
Opuntia robusta is a short shrub or tree-like cactus with flattened stem segments. It grows up to 15 feet (4.5 m) tall with an equal width. Stem segments are fleshy, blue-green to blue-grey, round, and up to 16 inches (40 cm) in diameter. They are hairless with areoles that bear tufts of numerous glochids and 2 to 12 sharp, up to 2 inches (5 cm) long spines. The yellow, bowl-shaped flowers are up to 2.8 inches (7 cm) long and 3.2 inches (8 cm) in diameter. They appear in late spring and summer at the edges of the upper stem segments. Flowers are followed by fleshy, barrel-shaped fruits that are pink or purple and up to 3.6 inches (9 cm) long.

Photo via thedangergarden.com
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 need 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 they can be grown in pots as well. To repot, ensure the soil is dry, remove the pot and knock away 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, make sure not to water a newly repotting Prickly Pear for a brief period to avoid rotting its roots.
Opuntia can propagate either by cuttings or by seed. To propagate by cuttings, sever pads from a plant and let them dry so that 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.
Origin
Opuntia robusta is native and endemic to Mexico.
Links
- Back to genus Opuntia
- Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
Photo Gallery
- Photo via floranelsalento.blogspot.com
- Photo via botanicalgarden.ubc.ca
- Photo via excellamattress.com
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