Edible supports for a fondant palm tree
Pretzel sticks sound promising! The normal sized ones aren't quite 10-15cm, but there are longer ones out there. You could also look for Pocky or some other kind of cookie stick - sometimes things like that are sold as edible coffee stirrers (maybe coated with chocolate). 

If you can't find any of that, it should all be easy enough to make yourself; pretty much any crispy cracker or cookie, rolled out into thin sticks instead of its normal shape, should get you started.