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

8 comments:

sarala said...

I loved learning about botanical dinosaurs such as the cycads and the gingko in high school biology.
Of course cycads don't make it through Chicago winters but gingko do. Cycads have a very pleasing geometry to them.
I had no idea they were so common in Australia though.
One thing I like about blogging is I learn something new every day.

Snail said...

They're very common in forests along the warmer parts of the east coast. In some areas there are almost as many cycads as trees. Very spectacular!

A few species make good indoor plants because they're slow growing and tolerant of low light. I keep thinking about getting some for the house but I'm mindful of the water situation. It's hard enough watering the plants I have already!

Geoff_D said...

Slow growing?! They are positively tardy. I have some seedlings from the big old cycad in my mother's garden, and I don't think I'll live to see them develop any kind of trunk. Definitely a long term project, propagating cycads.

Snail said...

I had one in my Townsville garden that grew quite quickly. By that I mean it put out a frond a year. But it was a big frond.

(Note: recall of events may be inaccurate)

tapperboy said...

*crosses fingers this comment is spelling error free*...

*raises hand*

Ummm, I wouldn't know how to spell peroffskayana to save my life but google reckons the spelling is to some degree incorrect, it suggests peroffskyana.

*sits on hand*

ps we have a Macrozamia johnsonii in our frontyard, growing extremely slowly :)

Snail said...

Oops! Am about to correct it. Thanks!

Woollybutt (Peter) said...

Hi Snail,

Popped in for a look.

We have heaps of Macrozamia communis growing here on the south coast of NSW. The older ones that develop a trunk are fascinating things to study close up, the communities of plants that grow on the trunk are amazing. Elkhorns, Birds-nest ferns, necklace ferns etc. I also notice that roos and wallabies eat the tips of the young fronds.

Nice work.
Woollybutt

Snail said...

That's an interesting observation about the herbivores. I guess the young shoots are soft and juicy. They wouldn't want to tackle some of those tough and spiky old fronds!