Description

An upright slow growing cycad with a rounded head of blue-green foliage. It is the largest of the Macrozamia and has been known to reach over 30 feet in the wild in Australia with a 2 foot thick trunk but is usually 10 to 13 feet, even with great age, and can be expected to be well under this size for many years in the garden. Still, it is a plant for a large garden as it has a spread from leaf tips that can be more than 15 feet wide. The growth point holds many 5 to 7 foot-long blue-green leaves that rise erect and then strongly arch over with 120 to 220 leaflets that face forward and are keeled along the rachis with soft pointed tips - the leaflets are 8 to 12 inches long in the middle of the leaf but reduced towards both the tip and the base with the basal leaves reduced to nearly spinelike all the way to the base of the leaf (important in distinguishing the species). Once mature, this plant puts on leaves continuously instead of in flushes like most other cycads do, and the full head of leaves can look somewhat palm-like or like grass trees (Xanthorrhoea or Dasylirion). As with other cycad genera, Macrozamia are dioecious, cone-bearing plants so there are plants that have male or female cones with the female cones typically broader and male cones usually longer and thinner. Plant in full sun to light shade in a well-drained soil and irrigate occasionally to infrequently. Hardy and evergreen to 20 °F. This cycad grows in Queensland, Australia from Emerald and Springure in the north to Injune in the south and west to the Carnarvon Gorge area where it is found in relatively high abundance. It is similar to Macrozamia johnsonii, which grows further to the south in New South Wales and has greener non-keeled leaves, and there is a slightly more blue-green color to the leaves that do not have the reduced leaflets all the way to the base of the leaf.