Opuntia microdasys

Natural origin of Opuntia microdasys

Opuntia microdasys is native to Mexico and grows naturally in desert and dry scrub.

Cultivated forms mainly differ in glochid colour, including yellow and white forms.

Everyday care for Opuntia microdasys

• Light: Place it in full sun or very bright direct light. Increase exposure gradually after a move from lower light.
• Temperature: Keep it frost-free. Normal warm room temperatures suit the plant while it is growing, with cooler conditions acceptable when growth has paused.
• Water: While new pads are forming, allow the cactus mix to dry before soaking it thoroughly and draining the pot completely. Use very little water while growth is paused.
• Humidity: Low humidity suits the pads and helps the mix dry at a healthy pace.
• Growing mix: Choose a gritty cactus mix with fast drainage and plenty of air around the roots.
• Feeding: Use a light cactus feed a few times while new pads are growing.
• Handling: Use tongs or thick protective gloves. The tiny glochids are barbed and can detach into skin or eyes.
• Repotting: Repot when the clump becomes unstable, roots fill the container or drainage slows.

Problems and symptoms in Opuntia microdasys

• A pad turns soft and dark near its base: Rot has started after the roots or pad base stayed too wet. Use a clean, disinfected blade to cut the soft area back to firm healthy tissue. Throw away the rotted piece, leave the healthy cut to dry, then pot it into fresh, dry cactus mix.
• Pads become deeply wrinkled while the mix is dry: The cactus needs water while new pads are growing. Water thoroughly and allow the mix to dry before watering again.
• Fresh pads are narrow, unusually long or leaning strongly: The plant needs stronger light. Move it gradually toward full sun.
• Irregular white cottony material or sticky patches appear between the evenly spaced areoles: Check closely for mealybugs or scale. Inspect the affected areoles closely and isolate the cactus. After confirming the pest, use a treatment labelled for it on ornamental cacti and follow the label's application and repeat directions.

Opuntia microdasys 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.

How the name Opuntia microdasys came about

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.