How Do You Spell PERIDERM?

Pronunciation: [pˈɛɹɪdˌɜːm] (IPA)

The word "periderm" is used in botany to describe the protective tissue that covers stems and roots of plants. Its pronunciation is [pəˈɹaɪdəɹm], with the stress on the second syllable. The first two letters, "per", come from the Greek word "peri", meaning "around" or "surrounding". The suffix "-derm" comes from the Greek word "derma", meaning "skin", "layer", or "covering". Therefore, "periderm" literally means "the protective layer that surrounds the stem or root", and its spelling follows typical English language rules for deriving words from Greek roots.

PERIDERM Meaning and Definition

1. Periderm is a noun that refers to a protective outer layer of tissue that forms in plants and some animals, serving as a defense against external factors such as physical damage, pathogens, and extreme weather conditions. In plants, periderm is commonly found in stems and roots, replacing the epidermis during secondary growth. It is composed of several layers, including the cork cambium, cork cells, and phelloderm.

   The cork cambium, also known as the phellogen, is a secondary meristem that produces cork cells towards the outside and phelloderm cells towards the inside. Cork cells are usually dead at maturity, characterized by their thickened walls containing suberin, a waxy substance that makes them impermeable to water and gas exchange. This property makes periderm an efficient barrier, preventing excessive water loss and reducing the risk of infection.

   Phelloderm, on the other hand, is a living parenchyma-like tissue located right beneath the cork cells. It serves as a source of replacing cells for the cork cambium to continue producing new protective layers.

   In animals, periderm is often found in developing embryos. It is a temporary layer that covers the skin during early stages of development, protecting the underlying tissues until they differentiate into their definitive forms. In humans and some other animals, periderm is eventually shed before birth, when it is replaced by the definitive epidermis.

2. In bot., the outer layer of bark.

   Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.

Common Misspellings for PERIDERM

• peri derm
• perid erm

Etymology of PERIDERM

The word periderm is derived from the Greek words peri meaning around or about, and derma meaning skin or covering. So, periderm literally means around the skin or outer covering.

Plural form of PERIDERM is PERIDERMS