Tephrocactus geometricus (A. Cast.) Backeb.
Opuntia geometrica, Tephrocactus alexanderi var .geometricus
Tephrocactus geometricus , also known as Tephrocactus alexanderi subsp. geometricus, is a small, branched cactus that forms attractive clumps of segmented, usually spineless stems. It grows up to 6 inches (15 cm) tall. The stem segments are spherical, up to 2 inches (5 cm) in diameter. They are gray-green to blue-green and take on red to purple hue in full sun. Spines are sporadically present in the upper areoles.
The flowers are white to light pink with a darker midstripe, appear in summer and last only one day.
Tephrocactus geometricus is native to western Argentina. It occurs in Catamarca province and areas close to the Bolivian border.
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 also be grown in pots. 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, ensure 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 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.
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