The young new leaves of the tree fern (Cyatheales) grow like spirals before they unfurl. The sunlight put them in the right light ;-).
While many ferns are able to achieve a widespread distribution because
of their spore reproduction, tree fern species tend to be very local.
This makes their species much more susceptible to the effects of local
deforestation. It is not known why species are not more widespread,
especially considering that they have sufficient height to have a
greater chance of getting spore into the wind stream.
Where feral pigs are a problem, such as in some Hawaiian rainforests, they will knock over tree ferns to root out the starchy pith, killing the plant (Wikipedia).
View Large On Black
© 2012 Ursula Sander - All rights reserved.