The term bark refers to all tissues of a woody stem or root occurring just outside of the vascular cambium, i.e., all tissues that could be stripped away from the woody core. The petiole or rachis of a long-lived leaf can theoretically also form patches of bark, but this normally is not observed. Stems of monocotyledons, especially trunks of arborescent types, often have an outer cover, sometimes appearing like a form of bark, but in these cases the origin of the cover is very different from that of dicotyledons and gymnosperms (other gymnosperms: Araucaria, Juniperus, and Cupressus). Ferns and other seedless vascular plants never form bark of any type.
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