Monday 15 January 2007

Cycads R Us

Australia is home to just over forty species of cycad. All are endemic. In fact, three of the four Australian genera to which these species belong (Bowenia, Lepidozamia and Macrozamia) are found nowhere else. (Cycas also occurs in SE Asia, eastern Africa and Madagascar.)

There are only two living species of Lepidozamia. Both of them are restricted to Australia. Lepidozamia hopei is a forest dweller from the Wet Tropics of Queensland. Growing to a height of 20m, it is probably the tallest cycad in the world. Its not so lanky relative L. peroffskyana is found in rainforest and wet sclerophyll from south-eastern Queensland to north-eastern New South Wales.

Of the two, L. peroffskyana is the more commonly cultivated. I photographed this specimen at the Royal Botanic Gardens in Melbourne.

This species is pollinated only by Tranes weevils*, which spend most of their lives in the male cones (reproductive structures). When the beetles visit the female cones, they carry pollen with them.


Read more

Hall, JA, Walter, GH, Bergstrom, DM and Machin, P (2004). Pollination ecology of the Australian cycad Lepidozamia peroffskyana (Zamiaceae). Australian Journal of Botany 52 (3): 333–343.

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* PDF file of PowerPoint presentation