Koanophyllon villosum grows as a small to medium sized shrub up to 3 meters in height (typically shorter). The stems and leaves often have a covering of short hairs. The leaves are arranged oppositely, are up to 7 cm long and 3 cm wide and are ovate shaped. The leaf margins range from entire to slightly dentate and have an obtuse leaf apex.The complete, perfect, actinomorphic flowers are arranged in a series of heads that form corymbs. Each head contains up to 15 flowers and is subtended by an involucre that is 3 mm in height. The involucre is covered with a series of phyllaries. Each phyllary is linear. The calyx is a ring of hairs and the corolla has 5 white to pink petals that are fused to form a tube. There are 5 stamens fused to the base of the corolla tube. The ovary is inferior and contains a single seed. The fruit is an achene that is black at maturity with the calyx hairs forming a pappus that assists in fruit/seed dispersal.