Jan 19 2010
Growth Upon Growth
Nature is such a free-for-all. Consider this backyard photo of the trunk to a small tree. Or maybe front-and-center in this photo is the growth of lichen, and the tree is just a stage.
Lichens are composite organisms consisting of a symbiotic association of a fungus (the mycobiont) with a photosynthetic partner (the photobiont or phycobiont), usually either a green alga (commonly Trebouxia) or cyanobacterium (commonly Nostoc). The morphology, physiology and biochemistry of lichens are very different from those of the isolated fungus and alga in culture. [Wikipedia]
