Cycas revoluta

Origins and background of Cycas revoluta

Cycas revoluta is native to parts of southeastern China, southern Japan and eastern Taiwan.

It grows as a subtropical shrub and belongs to Cycadaceae, the cycad family. Male and female reproductive structures are produced on separate plants.

Keeping Cycas revoluta healthy

• Light: Give very bright light with gentle direct sun. Increase direct sun gradually after a move.
• Water: Soak the potting mix, then wait until the upper part has dried before watering again. Empty water left in the outer pot.
• Potting mix: Use a well-draining mix with loam plus grit, pumice or coarse perlite.
• Temperature: Warm to moderate conditions suit container plants. Protect the pot and crown from hard frost.
• Feeding: Apply a balanced fertiliser as fresh fronds begin to appear.
• Repotting: Move up a pot size when roots pack the container or drainage becomes noticeably slower. Keep the centre of the crown above the mix.
• Grooming: Remove fully brown fronds close to the trunk and leave the central growing point undamaged.

Signs of trouble on Cycas revoluta

• White crusty patches build up on fronds or the trunk: Cycad aulacaspis scale can create dense pale coverings. Isolate the plant, remove loose scale where you can and use a scale treatment labelled for ornamental cycads if the insects keep returning.
• New fronds emerge small, yellow and distorted, then develop brown tissue: A shortage of manganese, sometimes made worse by stressed roots, can cause this pattern. Check drainage and root health, then use a fertiliser formulated for cycads if needed.
• Lower fronds yellow while the root ball stays wet: Compacted, very wet mix can stress the roots. Improve drainage and replace dense old mix if moisture lingers.
• Tiny pale speckles appear across the leaflets: Spider mites can cause these scattered marks. Inspect the undersides, rinse the fronds thoroughly and recheck the newest leaves.

Cycas revoluta is toxic to people and pets

• Keep every part of this plant away from children, cats and dogs, especially the seeds.
• All parts contain cycasin and related toxins, with the seeds posing the greatest risk.
• Poisoning can cause vomiting, stomach pain, weakness, liver failure, seizures or death. Treat any ingestion as an emergency and contact a veterinarian or medical professional immediately.

How the name Cycas revoluta came about

Cycas comes from Greek kykas, an old written form related to koikas, a word used for palms. The Latin epithet revoluta means rolled backwards and describes the strongly recurved edges of the leaflets.

Carl Linnaeus established the genus Cycas in 1753 in Species Plantarum, page 1188.

Carl Peter Thunberg first described Cycas revoluta in 1782 in Verhandelingen van de Hollandsche Maatschappij der Wetenschappen te Haarlem, volume 20, page 424.