Some of the most eye-catching fungi in the forest are cup fungi, a large, colorful group of fungi with fruiting bodies that are cup or saucer shaped. Despite their relatively similar forms, cup fungi are extremely diverse, consisting of members from a number of different families and genera in the class Ascomycetes. Cup fungi grow in a rainbow-like array of colors and from about a millimeter to hundreds of times that size in diameter. A variety commonly called the orange peel fungus (Aleuria aurantia), for instance, is a bright, citrus-hued fungus with a fruiting body that may measure as many as ten centimeters or more across, whereas the white or yellow Hymenoscyphus fructigenus cup fungus is so small that dozens of them may be seen on a single acorn or hickory shell.