sporangium

A sporangium is a specialized structure in fungi and plants that produces and releases spores, serving as a key site of sporogenesis and a means of dispersal. The term comes from Greek sporangion, meaning “seed vessel.”

In fungi, sporangia are typically asexual reproductive bodies located at the tips of hyphae called sporangiophores. Inside the sporangium, sporogenous tissue undergoes mitotic divisions to form numerous haploid sporangiospores. When mature, the sporangium ruptures or opens to release these spores, which can disperse by wind, water, or animals. In many fungal groups, sporangia function as a primary mechanism for rapid, clonal expansion, though sexual spores are produced by other structures in the fungal life cycle.

In plants, sporangia occur on the sporophyte and house diploid spore mother cells that undergo meiosis to produce haploid spores. This feature is characteristic of seedless vascular plants such as ferns and lycophytes, as well as bryophytes (mosses, liverworts, hornworts). Plant sporangia may be eusporangia, which arise from several initial cells and are larger, or leptosporangia, which originate from a single cellar and are often clustered on sporophylls as sori. The spores germinate to form the gametophyte generation, completing the alternation of generations common to these groups.

Spore dispersal by sporangia enables colonization of new habitats and contributes to genetic variation through sexual cycles in many lineages. Sporangia also provide useful characters for identifying and classifying fungi and non-vascular and seedless vascular plants.