Megaspore

Megaspore

Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These types of plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female (egg-producing) gametophyte, which is fertilized by sperm produced by the male gametophyte developing from the microspore. Plants which are known to do this include those in the following genera:

• Selaginella: the spikemosses, included within the lycopod, or clubmoss group
• Marsileaceae: the water-clovers, Marsilea, Pilularia, and Regnellidium
• Azolla: in the Azollaceae, within the ferns
• Salvinia: in the Salviniaceae, within the ferns
• gymnosperms and flowering plants