"Pavona forms foliaceous, encrusting or massive colonies. Foliaceous types have fronds that are entire and flat or twisted and fused together. In general, calices are on both sides of the vertically growing fronds or plates but on the upper face only of horizontal folia. Most colonies are pale brown. Some show shades of gray, pink, purple, green or yellow, and often the tops of the collines are paler or white. In some cases the calices are a different color from the rest of the coral. Tiny tentacles less than a millimeter in length are sometimes extended during the day. Calices are round, polygonal or oval. In many species hillocks called collines are present between the calices. These are usually acute and may be elongate. Some enclose a single calice, but most surround a short series, giving a complicated system of ridges and grooves. In Pavona clavus there are low walls between the calices. These are usually separated, each with its own wall. Calice diameter is usually between 2 and 3 mm. Septa are visible as fine lines running from one calice center to the next, continuing uninterrupted over walls and collines. Often they form characteristic star-shapes patterns over the surface of the corallum. They are extremely fine, and the coral is smooth to the touch. Pavona is a fairly common coral that is found in most reef habitats. Some of the massive colonies are large, and the foliaceous ones may form extensive tracts." (Dr. Elizabeth M. Wood, 1984).