A portion of phyllome marginal meristem (PO:0025404) tissue that is part of a leaf margin (PO:0025009) of a vascular leaf (PO:0009025) during a leaf expansion stage (PO:0001052) and has parts marginal and submarginal initials. [source: ISBN:0521288959, POC:curators]
Comment
Leaf marginal meristems develop on the lateral margins of a vascular leaf after the transition from a vascular leaf primordium (PO:0000017) and may contribute to expansion of the leaf lamina (PO:0020039). Marginal growth can occur in a vascular leaf primordium, but it is not considered part of a leaf marginal meristem. Leaf marginal initials (add) may give rise to leaf epidermis (PO:0006016) while leaf submarginal initials (add) may give rise to the leaf mesophyll (PO:0005645). May be of limited duration.