meristeemlaag

Meristeemlaag is a term used in botany to refer to one or more layers of meristematic tissue in plants. Meristematic tissue contains small, densely packed cells with high mitotic activity that remain undifferentiated and serve as the source of new cells for growth and organ formation.

In shoot apical meristem development, the meristem is often described as organized into layers. The outermost cell layers constitute the tunica, which is sometimes referred to as the meristeemlaag. The tunica typically divides primarily anticlinally, producing the epidermis and other outer tissues. Beneath the tunica lies the corpus, comprising the inner meristematic layers responsible for supplying inner tissues such as the subepidermis, cortex, vascular tissues, and pith. Depending on species, the corpus may be divided further into additional layers (often labeled L2 and L3) but the general principle remains: surface tissues arise from the tunica, inner tissues from the corpus.

The concept of meristeemlaag is also applicable to other meristems, including root apical meristems, though the exact organization and number of layers can differ among plant lineages. Variation exists among taxa, with some species showing more pronounced layering and others a simpler organization.

Understanding meristeemlaag helps explain how localized patterns of cell division and differentiation give rise to organized plant shapes and structures, such as leaves, stems, and roots. See also: meristem, apical meristem, tunica, corpus.