plumule

Plumule is the part of a seed's embryo that develops into the shoot system of a plant. In most seeds, it lies at the axial end opposite the radicle and above the cotyledons, and it contains the shoot apical meristem that will form the epicotyl and, subsequently, the first true leaves.

During germination, the plumule grows upward and emerges as the young shoot. In many monocot seeds, the plumule is protected by a coleoptile, a sheath that covers developing leaves. In dicot seeds, the plumule develops into the above-ground shoot after the seed coat is breached and germination proceeds.

Plumule is typically discussed alongside the radicle, which forms the embryonic root, and the cotyledons, which may serve as nutrient stores or initial photosynthetic organs. The precise arrangement of plumule relative to cotyledons varies among plant groups, but its fundamental role is to give rise to the shoot system.

Etymology: the term plumule derives from Latin plumula, a diminutive of plumus meaning feather, reflecting the perceived feather-like appearance of early shoots.