Large palm to 18 m tall with single, thick, non-branching trunk (1.2 m diameter) with a diamond-shaped pattern from old leaf scars and large crown of foliage at the top of the trunk. Long, stiff leaves (to 1.8 m) are made up of many leaflets that are dark green, lance-shaped and pointed (30 - 45 cm long), and the leaf stalk is covered with sharp, shiny green spines (5-8 cm) with a feathery appearance. Branched clusters of creamy yellow-white flowers open from a husk-like structure that appears in October to November on a long stem amongst the leaves, and are followed by fleshy, date-like fruit (1-5 cm long), ripening from orange-yellow to dark purple in summer.
Other palms lack a very thick trunk.
Thrives in a variety of habitats and soil types, tolerating cold and warmth, drought and floods, shade and sun, and salt spray as well as mountain climates. Sharp spines can cause injury to humans and animals.
Seed is spread by birds and water.
Displaces native trees through sheer size, and the growth of seedlings can produce an impenetrable, long-lived subcanopy. Reduces water tables and can alter dune form through sand build up around its roots and resulting erosion elsewhere.
1. Dig out seedlings and small plants (all year round): dispose of material at a refuse transfer station.
2. Drill and inject (all year round): drill holes at least 2.5 cm deep every 10 cm around trunk, near the ground, and inject each with 10 ml glyphosate (undiluted).
3. Cut and paint stumps (all year round): glyphosate (250ml/L). Leaves can be mulched, but dispose of trunk at refuse transfer station.
4. Overall spray (spring-summer): spray new growth with glyphosate (20ml/L) + penetrant.
Retreat any survivors after 1-2 months. Monitor the site for reinfestation or germination of seed bank. If possible track down and remove the seed source.