They produce shelf- or bracket-shaped fruiting bodies called conks. These lie in a close group of horizontal rows. Brackets can range from only a single row of a few caps, to dozens of rows of caps that can weigh several hundred pounds. They are mainly found on trees (living and dead) and woody debris. Some form annual fruiting bodies while others are perennial and grow larger year after year. Bracket fungi are usually tough and sturdy. Their spores, called basidiospores, are in pores on the undersurface.