Cycad  (Cycas calcicola)

Despite being strikingly distinctive and occurring beside the major north-south highway in the Northern Territory, Australia, this cycad was only recognised as recently as 1978 (4). The palm-like shrub (2) is distinguished by its long, flat, dark-green leaves with large numbers of very narrow leaflets, densely covered with short, matted hairs below, and sometimes above (4). This slender-trunked form of Cycas is also characterised by pronounced silver or bluish-grey colouration through young upright leaves, which can most frequently be seen in the new flush of growth after a fire (2) (5). The slender, greyish male pollen cone is ovoid in shape, 17 to 26 centimetres long and 5 to 6 centimetres wide (2). The megasporophylls, a leaf-like structure that holds the female gamete, are 12 to 18 centimetres long and either grey or brown (4).

Located in a few disjunct areas across the Northern Territory of Australia (5).

Found amongst sparse woodland on sandstone or limestone, where the water table is near the surface (5).

Cycads are dioecious plants, meaning that there are separate male and female plants, and the female produces seeds while the male produces cones with pollen in them. Plants of this taxon have generally been considered to be wind pollinated, but several recent studies suggest that insect pollination is more likely. The seeds produced are typically large with a hard, stony layer (sclerotesta) beneath a fleshy outer coat (sarcotesta), attracting animals such as birds, rodents, small marsupials and fruit-eating bats, which serve as dispersal agents. In most cases, the fleshy coat is eaten off the seed rather than the entire seed being consumed. Cycads are long-lived and slow-growing, with slow recruitment and population turnover (6).

This species is widespread and not considered to be at risk (4).

This cycad is listed on Appendix II of CITES, which regulates the plant's import and export across international borders (3). Otherwise, no conservation measures are currently in place for this species.

For more information on Cycas calcicola see:

• Palm and Cycad Societies of Australia (PACSOA):
  www.pacsoa.org.au/cycads/Cycas/calcicola.html
• The Virtual Cycad Encyclopedia:
  www.plantapalm.com/vce/vce_index.htm

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