Cycads have an evolutionary history dating back to the dry, cool age of the Triassic, when much of the world’s terrestrial landscape was inhospitable to spore-producing plants. They have carried the evolutionary breakthrough of the seed from an ancient group of now-extinct plants called Bennettitaleans, to the present.
Cycads are pollinated mainly by weevils and thrips, which carry out much of their life cycle within the tissues of the male and female cones. In what could be considered an insightful adaptation to global warming (albeit at a micro-level), an ABC Science Online article by Stephen Pincock reveals how another species of cycad Macrozamia lucida uses a stockpile of sugars, starch and fats to heat their cones to around 12 degrees Celsius above air temperature to encourage thrips to evacuate to the more appealing climes of the female cones.
Whilst cycads are pollinated by weevils and thrips, the distribution of their seeds is reliant upon another group of animal carriers.
The world’s tallest cycad Lepidozamia hopeii can reach twenty-metres. Every five-years-or-so, female plants produce large cones that mature over about ten months. They then collapse and bright-red seeds adorn the forest floor at the base of the plant. Mammals carry individual seeds away from the intensity of competition and remove the delectable red aril from the seed, leaving the camouflaged core to recruit away from the competitive disinterests of the parent plant.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Neil – cycads have a real cult following among collectors – so many species have CITES restrictions – people will go to crazy lengths to obtain rare specimens, including breaking the law, smuggling, and dangerous adventures in remote parts of the world. The African Encephalartos genus is fantastic – bizarre even.
Then there’s the contoversy as to whether cycads including their pollen cause Alzheimer’s, Parkinson’s and Motor Neurone Disease
Love these weird and wonderful creations from nature!
I think they’ve ruled out cycad pollen/flour as a cause for MND,Alzheimer’s and Parkinson’s,Luke.
http://www.mndassociation.org/research/for_researchers/international_symposium/17th_international_symposium_on_alsmnd/my_symposium/daily_bulletins/opening_session.html
Cycad (revoluta) pollen.I have removed pollenn from a male cone by brushing underneath the scales.The scales on the centre of the cone were fully open but very limited pollen fell out when shaking the cone. The pollen is more orange than yellow. Will this pollen be suitable for pollinating a female?