Sporangia

Sporangia are spore-producing structures found in fungi, many plants, and some algae, and they serve as sites for the formation and release of spores that propagate organisms. A sporangium is a discrete container in which spores develop, typically by meiosis, and are dispersed to new environments.

In fungi, sporangia are sac-like bodies borne on specialized hyphae called sporangiophores. They house sporangiospores and form part of asexual or occasionally sexual life cycles. The sporangial wall may be multi-layered, sometimes with a peridium, and spores are released by rupture or mechanical discharge when mature.

In bryophytes (mosses and liverworts) and pteridophytes (ferns and horsetails), sporangia are part of the sporophyte. Moss capsules and liverwort thallus capsules produce spores, while many ferns carry sporangia in clusters called sori on the undersides of fronds; a specialized annulus often drives rapid dehiscence to disperse spores.

In seed plants, sporangia include microsporangia and megasporangia, which generate male and female spores, respectively. Microsporangia produce pollen grains; megasporangia, contained within ovules, develop megaspores that give rise to the female gametophyte. These sporangia are typically protected by surrounding tissues as part of the plant’s reproductive organs.

Spore dispersal by sporangia is a major driver of plant and fungal reproduction and distribution, enabling colonization across terrestrial and aquatic environments.