Opuntia microdasys var. albispina

Background of Opuntia microdasys var. albispina

This white-glochid form belongs to the Mexican species Opuntia microdasys, which grows naturally in desert and dry shrubland.

You may still see var. albispina used for this pale form, although it is now grouped under Opuntia microdasys.

Care guide for Opuntia microdasys var. albispina

• Light: Give the cactus full sun or very bright direct light to keep the pads compact and well shaped.
• Temperature: A warm, frost-free position suits this cactus.
• Water: Wait until the cactus mix is dry, then water thoroughly until the mix is evenly wet. Let the container drain completely and keep the mix much drier during slow growth.
• Humidity: Dry indoor air and good ventilation suit the pads and help the cactus mix dry efficiently.
• Growing mix: Use a gritty, fast-draining cactus mix in a pot with a clear drainage hole.
• Feeding: Use a light cactus feed while new pads are forming.
• Handling: Use tongs or thick protective gloves to lift or repot the plant. The white glochids detach easily and can irritate skin and eyes.
• Repotting: Repot when the plant becomes top-heavy, roots fill the pot or the old mix drains slowly.

What to watch for in Opuntia microdasys var. albispina

• Pads become wrinkled and slightly thinner while the growing mix is dry: The cactus has used some of its stored water while growing. Water thoroughly, let the container drain, and wait for the mix to dry before watering again.
• White material appears irregularly between the normal areoles, especially with stickiness or visible insects: Mealybugs may be present. Isolate the cactus. For mealybugs, choose a treatment whose label specifically lists mealybugs for ornamental cacti and follow the repeat schedule on the label.
• A lower pad develops a soft brown or black area: Excess moisture has started rot. Cut away the damaged area to firm healthy tissue using a knife cleaned and disinfected before use. Discard everything soft or black, allow the cut to dry, then set the healthy section in fresh, dry cactus mix.
• New pads become long and narrow: The plant needs more light. Increase direct light gradually.

Opuntia microdasys var. albispina has sharp parts

• This plant is non-toxic to cats and dogs. Its effects on people are unclear.
• Fine glochids and larger spines can lodge in skin, paws, mouths or eyes and cause painful irritation.
• Handle it carefully. Contact a veterinarian or medical professional after a serious injury, especially to the eye.

What does the name Opuntia microdasys mean?

Opuntia traces back to Opus and the Opuntian plants mentioned in classical Greek writing. Microdasys combines Greek mikros, meaning small, with dasys, meaning hairy or shaggy, referring to the dense tufts of tiny barbed bristles called glochids.

Philip Miller established the genus Opuntia in 1754 in The Gardeners Dictionary Abridged, fourth edition.

Johann Georg Christian Lehmann first described it as Cactus microdasys in 1827 in Index Seminum (HBG, Hamburgensis), volume 1827, page 16. Louis Karl Georg Pfeiffer later placed it in Opuntia as Opuntia microdasys in 1837 in Enumeratio Diagnostica Cactearum, page 154.