Disocactus ackermannii

Botanical identity and natural origin of Disocactus ackermannii

Disocactus ackermannii is native to southern Mexico, where it grows as an epiphyte in seasonally dry tropical vegetation. Its roots occupy pockets of organic material and crevices on trees, with regular wetting and plenty of air around them.

Older horticultural references often use the name Epiphyllum ackermannii. The accepted botanical name is now Disocactus ackermannii, while Epiphyllum remains familiar in cultivation.

Growing Disocactus ackermannii indoors

• Water: Water thoroughly when the upper part of the potting mix has begun to dry. When growth slows, wait longer between waterings and keep a little moisture in the mix.
• Light: Bright filtered light or partial shade suits the stems, with gentle direct sun if you introduce it gradually.
• Potting mix: Use a loose epiphytic cactus mix that holds some moisture and drains quickly; bark with pumice or perlite works well.
• Flowering: When buds appear on mature stems, keep watering and temperature steady and leave the plant in the same place.
• Temperature: Keep it frost-free and protect the fleshy stems from prolonged cold.
• Humidity: Moderate indoor humidity is usually enough when air can move around the stems.
• Feeding: Feed lightly while new stems are growing.
• Repotting: Repot when roots fill the container or the potting mix has broken down and drains slowly.
• Propagation: Stem cuttings can be rooted after the cut surface has dried. It can also be grown from ripe seed.

Common issues in Disocactus ackermannii

• Sunken green-brown or brown spots with a yellow halo: The fungus Neoscytalidium dimidiatum can cause this type of brown spot. Isolate the plant and remove badly affected segments with a clean tool. Keep the stems dry, and only use a fungicide if its label specifically allows use on cacti for fungal leaf or stem spots.
• The stem base or roots become soft: The roots or base may be rotting in potting mix that stays too wet. Remove damaged roots and cut any soft dark tissue back to firm healthy tissue with a clean blade. Discard the rotten parts and repot in fresh loose potting mix.
• Stems become deeply wrinkled: The plant may be too dry or the roots may be damaged. Check moisture in the potting mix first, then inspect the roots if the stems stay wrinkled after a thorough watering.
• Cottony insects or hard brown bumps appear at stem joints: Mealybugs or scale can settle in the notches. Isolate the plant, remove visible pests and treat with a product labelled for the pest. Check the joints again between treatments and repeat only as directed on the label.

Keep Disocactus ackermannii away from children and pets

• Keep this plant away from children, cats and dogs.
• Its effects after chewing or swallowing are unclear, and plant material can still cause an upset stomach.
• Contact a veterinarian or medical professional if symptoms develop or do not settle.

Where does the name Disocactus ackermannii come from?

Disocactus combines Greek dis, meaning twice, and isos, meaning equal, with cactus, referring to the two similar sets of floral segments. Ackermannii honours the German cactus grower Georg Ackermann, who brought the plant from Mexico to England in 1824.

John Lindley established the genus Disocactus in 1845 in Edwards’s Botanical Register, volume 31, plate 9.

Adrian Hardy Haworth first described it as Epiphyllum ackermannii in 1829 in Philosophical Magazine and Annals of Philosophy, new series, volume 6, page 109. Ralf Bauer later placed it in Disocactus as Disocactus ackermannii in 2003 in Cactaceae Systematics Initiatives, volume 17, page 16.