pine cones
Posted by sydney tilmon on April 28, 2007
Q: why does a pine cone when fully opened close up again when put in water
State: Georgia
A: I can't say that I understand the actual physics involved, but pine cone scales are definitely affected by moisture, as you've noted, and this causes their movement - either to close or open. The winged seeds of pines are usually small and disperse best in dry weather. So, under dry conditions, the cone scales, when ripe, will open and allow its seeds to scatter but on wet days, when dispersal is not so good, moisture causes the scales to close up and keep the seeds inside until later. This is a really good adaptation for getting your seeds as far from the parent tree as possible. Thanks for asking.
John Wiessinger ( April 30, 2007)