Lepidozamia Regel comprises just two species — both endemic to the rainforests of eastern Australia — but one of them, Lepidozamia hopei, holds the record for the tallest living cycad on Earth, with trunks exceeding 20 m. The genus is a living link to the ancient Gondwanan cycad flora of Australia and a spectacular landscape plant for subtropical and warm-temperate gardens with sufficient rainfall and humidity.
Taxonomy
Family Zamiaceae, order Cycadales. Two species: Lepidozamia hopei (Hope’s cycad, from tropical Queensland) and Lepidozamia peroffskyana (pineapple zamia, from south-eastern Queensland and north-eastern New South Wales). Both are restricted to eastern Australian rainforests and wet sclerophyll forests.
Geographic range
Lepidozamia hopei: tropical rainforests of far north Queensland (Daintree region and surrounding areas), at low to moderate elevations. Lepidozamia peroffskyana: subtropical and warm-temperate rainforests and wet sclerophyll forests of south-eastern Queensland and north-eastern New South Wales, extending further south and to higher elevations than Lepidozamia hopei.
Conservation and CITES
Both species are protected under Australian legislation. Lepidozamia hopei is relatively secure within its rainforest habitat (much of which is within the Wet Tropics World Heritage Area). Lepidozamia peroffskyana is more widespread but faces pressure from habitat clearing. Both species are listed under CITES Appendix II.
Cultivation
Light
Partial shade to filtered light. Both species are rainforest plants and prefer protection from intense direct sun, particularly in hot climates. Bright, filtered light under a tree canopy is ideal.
Temperature and cold hardiness
Lepidozamia peroffskyana is the hardier of the two, tolerating brief frosts to approximately −4 to −5 °C (USDA zone 9b) in well-drained soil. Lepidozamia hopei is more tropical and damaged below approximately −2 °C.
Substrate and watering
Humus-rich, well-drained but moisture-retentive soil — reflecting the rainforest origin. More water and organic matter than for arid-climate cycads. Regular watering during the growing season; reduce in winter.
Propagation
Dioecious. Large seeds with a red sarcotesta. Standard cycad seed preparation and sowing protocols. Germination in 8–16 weeks at 25–28 °C. Seedling growth is moderate. Neither species offsets readily; seed is the primary method.
Pests and diseases
Scale insects, mealybugs. Root rot in waterlogged soil. The cycad blue butterfly (Chilades pandava) is an increasing threat in eastern Australia.
Species of Lepidozamia
- Lepidozamia hopei — Hope’s cycad; tropical Queensland (Daintree region); the tallest living cycad (trunks to 20+ m); frost-tender
- Lepidozamia peroffskyana — pineapple zamia; south-eastern Queensland and north-eastern New South Wales; hardier (−4/−5 °C); the more commonly cultivated species
Authority websites
The Cycad Pages — Royal Botanic Gardens Sydney
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/cycadpg?taxname=Lepidozamia
World List of Cycads — https://www.cycadlist.org/
PACSOA — https://www.pacsoa.org.au/wiki/Lepidozamia
Bibliography
Jones, D.L. — Cycads of the World. 2nd edition, 2002.
Hill, K.D. — “The genus Lepidozamia.” Various publications in Telopea.