The coiled portion is formed by two concentric layer of columnar or cuboidal epithelial cells. The amnion is characterised by cuboidal and columnar epithelial layers. The "stratum basale" is a single layer of columnar or cuboidal basal cells. There are three principal shapes of epithelial cell&colon; squamous, columnar, and cuboidal. They are lined with respiratory epithelium, which is classified as ciliated pseudostratified columnar epithelium. It is a columnar or conical evergreen conifer with densely growing horizontal branches. The cells are often columnar and hexagonal in shape. The nasopharynx is lined by respiratory epithelium that is pseudostratified, columnar, and ciliated. This kind of epithelium is therefore described as pseudostratified columnar epithelium. Compared with other examples of columnar jointing, the Postpile has more hexagonal columns. They are covered by columnar epithelium, which lacks pain receptors. The monument protects Devils Postpile, an unusual rock formation of columnar basalt. The endoderm consists at first of flattened cells, which subsequently become columnar. Smaller cacti may be described as columnar. Taproots may aid in stabilizing the larger columnar cacti.