Macrozamia riedlei
zamia palm
Overview
Macrozamia riedlei is a long-lived cycad in the family Zamiaceae, not a true palm despite the common name. It forms a stout, mostly underground trunk topped by a spreading crown of stiff, arching, palm-like fronds 3.3-6.6 feet (1-2 m) long, occasionally longer. Each frond bears many narrow, dark green leaflets along a slightly twisted rachis. Plants are either male or female; mature specimens produce large cones at the centre of the crown, the female cones barrel-shaped and up to 16 inches (40 cm) long, holding seeds with a fleshy red outer coat. Macrozamia riedlei grows in jarrah and wandoo woodland on sandy and lateritic soils and is adapted to drought and periodic fire, often coning strongly in the season after a burn. Specialised coralloid roots host nitrogen-fixing cyanobacteria, allowing it to grow on poor soils. All parts, particularly the seeds, contain the toxins macrozamin and cycasin and are poisonous to people and livestock if eaten. Growth is very slow, and plants live for many decades.
Native Range
Macrozamia riedlei is native to south-western Western Australia, where it is common in jarrah and wandoo forest and woodland. It grows on sandy, gravelly, and lateritic soils in a winter-rainfall, dry-summer climate.Suggested Uses
Used as a feature and structural plant in dry, low-water, and native gardens, and in fire-adapted bushland settings. Its stiff frond crown suits gravel gardens and rocky slopes, and because all parts are toxic, it is planted where livestock cannot graze it on rural properties.How to Identify
Appearance
Size & Dimensions
Height3'4" - 6'7"
Width/Spread6'7" - 10'
Bloom Information
As a cycad, Macrozamia riedlei produces cones rather than flowers. Pollen and seed cones develop mainly from late winter into spring, and coning is often heavier in the season after fire. Female cones ripen over many months to release seeds with a fleshy red coat that are spread by animals.
Detailed Descriptions
Foliage Description
Dark greenGrowing Conditions
Sun Requirements
Requires 5-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow Macrozamia riedlei in full sun to light shade on deep, sandy, sharply drained soil. It withstands extended drought, heat, and poor soils once established, drawing nitrogen from its specialised coralloid roots. Water occasionally during establishment, then little thereafter, as it is prone to rot in wet or heavy ground. It tolerates light frost but grows fastest in warm, dry-summer climates. Growth is very slow, with only a few new fronds added each year, so plants change little from season to season. All parts contain macrozamin and cycasin and are poisonous to people, pets, and livestock if eaten, and contact with the seeds can irritate skin.Pruning
Old, browned, or damaged fronds can be removed at the base once they die down, in late winter before new growth flushes. Fresh fronds emerge in a single annual flush and harden over several weeks. No other pruning is needed.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter
Container Growing
✓ Suitable for container growing
Minimum container size: 10 gallons