Epicotyls

Part of speech: noun

Definitions

1. The part of a seedling that develops into the stem above the cotyledons
2. The region of an embryonic plant that grows into the stem and sometimes develops foliage
3. The section of an immature plant that connects the seed to the above-ground parts after germination

Etymology: "Epicotyls" is simply the plural of "epicotyl", so the history belongs to the singular. The term is built from two Greek elements: "epi-", meaning "upon" or "above", and "cotyledon", the seed leaf of a germinating plant. The "-yl" ending is a modern botanical convention borrowed from chemistry's "-yl" suffix, which was used to name the stem or main part of a structure. Put together, the name describes exactly what the structure is: the part of the young stem that sits above the cotyledons, the seed leaves. Below it lies the hypocotyl, which runs down toward the roots, so the epicotyl marks the point where the shoot begins its climb toward light. Botanists formed the term in the modern period from classical roots rather than inheriting it from ancient writers, which is why it reads like a technical coinage: a precise label for a part of the seedling that earlier naturalists described without a dedicated name.