Disocactus crenatus (Beavertail)

A broad-stemmed form of Disocactus crenatus

Beavertail is the horticultural name for broad, flattened plants of Disocactus crenatus; it describes the stem shape and does not denote a separate cultivar.

The species ranges from Mexico into Central America and grows on trees in seasonal tropical vegetation. Its exposed roots receive periodic rain followed by rapid drainage, while surrounding vegetation softens the strongest sun.

Care for water-storing roots and leaves

Support, pruning and stem care

A hanging basket or high stand lets the beavertail-like segments arch naturally. Support a heavy crown with a broad hoop or loose tie at the base if necessary; tying individual flat stems upright can split their joints.

Light

Give this epiphytic cactus strong filtered daylight close to an east window or set it back from intense south and west glass. A short period of mild morning sun is useful after acclimation; fierce midday exposure can yellow, bleach or cork the broad faces.

Watering

During active growth, water when the top third of the substrate is dry and slight moisture remains deeper down. Saturate the root ball and allow complete drainage.

Temperature

In bright winter conditions, a cooler, frost-free position is suitable if the root ball stays dry.

Fertilising

Feed at a low dose during new stem production. Once growth firms and buds develop, a balanced or modestly lower-nitrogen formula is suitable.

Repotting

Repot when the medium has decomposed, roots densely occupy the pot, watering becomes uneven or the broad top growth overbalances the container. Do not disturb a stable, slightly tight root ball immediately before flowering.

Root, stem and leaf problems in Disocactus crenatus (Beavertail)

• Broad, scalloped stems resemble beaver tails: That broad, flattened shape is normal for Beavertail and is not caused by pressure. Handle the joints carefully because a heavy mature segment can snap at a narrow connection.
• A healthy segment breaks off: Mechanical damage is common on long trailing cacti. Trim the break cleanly, allow the cut end to dry, then root it as a cutting; support the remaining stems with loose ties.
• The plant grows but does not flower: Immaturity, insufficient light or a lack of a cooler, somewhat drier winter rest can delay buds. Keep it bright without scorching and avoid repeatedly moving it once buds form; no single change will force flowering.
• The lowest segment turns soft in a wet pot: The roots or stem base are beginning to rot. Cut off decay before it travels upward, save a firm segment as a backup cutting and restart in a smaller pot with loose, fast-draining mix.
• White cottony insects sit in the scallops: Mealybugs hide along stem margins and joints. Isolate the plant, clean every notch and repeat treatment using our mealybug guide

Keep Disocactus crenatus (Beavertail) 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.

Who first published Disocactus crenatus, and what does the name mean?

Disocactus combines Greek dis, meaning twice, and isos, meaning equal, with cactus, referring to the two similar sets of floral segments. Crenatus means scalloped or furnished with rounded notches.

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

John Lindley first described it as Cereus crenatus in 1844 in Edwards’s Botanical Register, volume 30, issue 1, page 31. Miguel Ángel Cruz and Salvador Arias Montes later placed it in Disocactus as Disocactus crenatus in 2016 in Willdenowia, volume 46, page 157.