sporangion

Sporangion is the singular form of sporangia, a term used in Greek-derived scientific language. In modern English, the standard singular is sporangium and the plural is sporangia. A sporangion or sporangium is a spore-producing structure found in fungi, algae, and plants, serving as a vessel in which spores develop and are released for dispersal.

In fungi, sporangia are typically sacs on specialized hyphae called sporangiophores. They often produce asexual spores, known as sporangiospores, by mitosis. Some fungi also form sexual cycles that involve more complex structures such as zygosporangia, where sporangia participate in the formation of zygospores.

In plants, sporangia are key elements of the life cycle, especially in non-seed plants like ferns and mosses. They are usually diploid structures formed on the sporophyte and, by meiosis, produce haploid spores that give rise to the gametophyte generation. In ferns, sporangia are frequently grouped into sori on the undersides of fronds, sometimes protected by an indusium.

In seed plants, spores are not released as free-living organisms, but the plant still bears sporangia. Microsporangia produce microspores that develop into pollen grains, while megasporangia produce megaspores that develop into the female gametophyte within the ovule.

Sporangia exhibit diverse shapes and dehiscence mechanisms, from simple sacs that rupture to specialized openings. They are central to the reproductive and dispersal strategies across multiple major biological lineages.