Hypogaea is a term with multiple established meanings in biology and archaeology.
1. Fungal genus — Hypogaea is a fungal genus in the family Agaricaceae. It is a monotypic genus, containing the single secotioid species Hypogaea brunnea, which was described as new to science in 1963 by mycologist Egon Horak. The species is also known by the synonym Setchelliogaster brunneus (Singer, 1971).
2. Specific epithet in botany — Hypogaea is used as a species epithet meaning "under the earth" (from Ancient Greek hypó "under" and gê "earth"). It is most notably applied in the scientific name of the peanut, Arachis hypogaea L., named by Carl Linnaeus. This refers to the plant's geocarpic growth habit, in which the seed pods develop underground after the flower stalk (peg) bends toward the soil. The peanut is a legume crop cultivated in tropical and warm regions worldwide for its edible seeds.
3. Plural of hypogeum — Hypogaea is also the plural form of hypogaeum (or hypogeum), an architectural term referring to underground chambers or tombs, such as those found in ancient Roman, Minoan, and Maltese archaeological sites (e.g., the Ħal Saflieni Hypogeum in Malta).
