Hipogeális

Hipogeális is a term used in botany to describe a mode of seed germination in which the cotyledons stay below the soil surface after germination. In hipogeal germination, the epicotyl elongates and the shoot tips emerge above ground, while the cotyledons remain subterranean and often function as nutrient reserves during the early stages of seedling development. This contrasts with epigeal germination, where the cotyledons and the seedling’s first leaves emerge above the soil.

In seeds that undergo hipogeal germination, the growing point is usually protected underground, reducing exposure of delicate tissues to drying, heat, and some herbivores. The true leaves develop after the cotyledons have remained underground, and photosynthesis is carried out by these true leaves once they reach the surface. The process often involves a specialized shoot structure, such as a coleoptile in certain monocots, that protects the young shoot during emergence.

Hipogeal germination is common in many monocotyledonous plants, particularly among cereal crops. Examples typically cited include maize (corn), wheat, barley, and sorghum. The prevalence of hipogeal germination among these crops can influence agronomic practices, such as seedling care and soil conditions, because early seedling sensitivity to surface conditions can differ from that of epigeal species.

Etymology-wise, the name derives from Greek roots meaning under the earth. In practice, hipogeális is the term used in some languages (and hipogeal in English) to distinguish this underground cotyledon condition from epigeal germination.