Lots of fungi actively release their spores.. I've observed many of these in the field. This explains it fairly well: http://www.anbg.gov.au/fungi/dispersal.html Active spore release Once again, we'll start with a common mushroom growing in the middle of a field. As explained in the TWO MAJOR GROUPS SECTION the gills of a mushroom are lined with spore-bearing basidia. When a spore is mature it is forcibly shot from the basidium, into the air space between the gills. This is explained in more detail in the MUSHROOM SPORE DISCHARGE SECTION. While the spore is ejected horizontally with considerable force (up to 25,000 times the force of gravity), air resistance stops the spore in a fraction of a millimetre. The air in the space between two gills is still, so after coming to a stop the only influence on the spore is gravity and the spore falls downward. Once the spore has fallen below the bottom edge of the mushroom cap, and is clear of the gills, it strikes air that is not still. Even on what looks like a windless day, there are always slight breezes. While a human may not feel them, they are usually strong enough to be felt by a spore that is only about a hundredth of a millimetre long. These micro-breezes may pick up the spore and carry it higher into the air and away from the parent mushroom. The spore may come to rest a metre or a kilometre or even further away from the mushroom. It may come to rest on a grass blade, be eaten by a kangaroo that then moves away a few more kilometres and deposits it in a dropping. A basidiomycete with a very different active method of spore dispersal is the Cannonball Fungus. The "egg" inside the two millimetre diameter cup contains a mass of spores and is forcible flicked out of the cup. In a cup fungus click to enlarge the surface of the cup is lined with the spore-producing asci. As the spores in an ascus are maturing, fluid pressure builds up in the ascus. At maturity, the pressure is sufficient to force the spores out through the top of the ascus. In some species of cup fungi there is a little lid at the top of the ascus which is forced open to allow the spores out. In others the tip of the ascus ruptures more irregularly. The spores may be shot several centimetres up into the air and, as in the case of the mushroom, air currents carry the spores further afield. From the structure of a cup fungus, you will realise that many asci can simultaneously shoot their spores. Often when you pick up fresh cup fungi the mechanical disturbance of picking up a specimen is enough to jolt thousands of mature asci into releasing their spores and, if you are attentive, you will see a small cloud of spores arising from the fungal surface. Many, but by no means all, of the flask fungi click to enlarge release their spores actively. Flask fungi differ fundamentally from the cup fungi. In the latter the asci line the surface of an open cup or disk but in the flask fungi the asci are contained within a chamber that has only a narrow opening at the top. So there is no mass firing of asci. Instead, when an ascus is mature its tip extends to the opening, shoots out its spores and then collapses back into the chamber. Then another ascus can have its turn and so on. The flask fungi also get a mention in the passive release section below.