Abstract

The first periderm of the stem in most trees is initiated superficially in the outer cortical layer (either first or second cortex), whereas in herbaceous and shrubby members it may originate from the outermost layer (epidermis) to deep-seated tissues. With the exception of Melaleuca leucadendra, the place of the origin of the first periderm appears in the same tissue along the entire cylinder. But the periderm of Melaleuca leucadendra develops in a curved or wavy band from the epidermis to the deep cortex.