Work by Mats Wedin and colleagues highlights both the versatility of fungi and the complications these unsung organisms pose for the biologist. Two of the ways in which fungi make a living are as saprophytes, drawing sustenance from decaying matter, and as lichens, in which they form an intimate relationship with green algae or photosynthetic bacteria. Evidently, however, a single fungal species can adopt either lifestyle according to circumstance (New Phytol. 164, 459–465; 2004).