About

Cycas armstrongii is a species of cycad in the genus Cycas, endemic to the Northern Territory of Australia. It is found from Darwin to the Mary River, the Finniss River in the west to the Arnhem Highway in the east, and north of Pine Creek. It also occurs on the Tiwi Islands and the Cobourg Peninsula.

The stems reach 3 m (rarely 6 m) tall, with a diameter of 5–11 cm. The leaves are (very unusually for a cycad) deciduous in the dry season (though persistent if grown in moister situations), 55–90 cm long, slightly keeled or flat, pinnate with 100-220 leaflets; the leaflets densely orange-pubescent at first, then glossy bright green above, light green below, 5.5–14 cm long and 4.5–8 mm wide, angled forward at 40 degrees. Mature plants have around 50 leaves in the crown.

Where it grows

This cycad is common in open forest and woodland around the Top End and can be easily confused with Cycas maconochiei. It usually grows on well-drained sandy and lateritic soils. While locally abundant, less than 1% of these living fossils are located within conservation reserves.

Other Cycas plants

Cycas aculeata · Cycas aenigma · Cycas angulata · Cycas annaikalensis · Cycad · Cycas arenicola · Cycas arnhemica · Cycas badensis · Cycad · Cycas basaltica · Beddome’s Cycas · Cycas bifida