Some fungi fire their spores with an acceleration above 10,000 g
Many fungi do not wait for the wind. Certain species launch single spores using a tiny water droplet, known as Buller's drop, that flings each one off at a starting acceleration topping 10,000 g. Other fungi build pressure until spores burst out explosively, and stinkhorns simply recruit flies with a putrid smell.
A spore is a reproductive unit built for travel and endurance, able to wait out bad conditions, sometimes for long periods. The name comes from the Greek spora, a sowing. Unlike a gamete, a spore does not need a partner: it can germinate and grow on its own. Plants, algae, fungi and protozoa all use them, while bacterial spores are purely survival capsules with no role in sex.
Spores are the cheapest offspring an organism can make, needing less energy and material than any other kind. Because they carry almost no food, animals largely ignore them, though fungi and bacteria do not. Ferns scatter extremely light spores on the wind, a smoothcap moss releases spores by vibrating its capsule, and one spikemoss, Selaginella lepidophylla, disperses partly by tumbling like a tumbleweed. Seeds differ fundamentally: a spore is a single cell, while a seed already holds a multicellular embryo.
Under a microscope, spore surfaces carry telltale markings. A trilete spore bears three lines radiating from a point, showing it once sat in a tetrahedral group of four; a monolete spore has one line. Wider grooves called colpi help identify plant groups, and eudicots have spores with three of them. Some plants make two sizes, larger megaspores that grow into female gametophytes and smaller microspores that become male ones.
Spores also carry deep history. Tetrads of spores wrapped in envelopes, dating from about 470 million years ago in the mid-Ordovician, are the earliest evidence of plants on land, from a time that has yielded no larger plant fossils. Most researchers think spores evolved as early land plants adapted to life out of water, their thick walls protecting offspring from harsh weather, although a newer idea suggests they arose from errors in algal meiosis before land plants existed.
Source: Spore
