Fungus
Mushrooms are probably my second most photographed subjects. I find them very interesting. Did you know that the visible mushroom is really only the fruiting body of the fungus? Hidden underground, below the mushroom, is where the mycelium is. If you've ever dug into soil and have seen little white hair like matter, that's mycelium. It is basically the main part of a fungus and is always underground feeding and spreading. Eventually, when conditions are right, it produces a fruiting body (mushroom) for the purpose of dropping spores for reproduction. Once the mushroom opens and drops it's spores, it quickly decomposes, but the mycelium remains below. The dropped spores (think of them like seeds) can then colonize a new area and grow new mycelium.