 The family is widely distributed, with many species found in temperate regions, and most are saprobic on wood and bark, although a few are parasitic on plants.The defining feature of this group—the hysterothecium—is a dense, persistent darkly colored structure, with a boat-like shape and a pronounced lengthwise slit.Hysterothecia are capable of opening partially to reveal a lenticular (lens-shaped), disk-like hymenium or closing tightly in response to relative humidity.