Each sporangium in a sorus carries 64 spores. Each sporangium in a sorus carries 32 brown spores. The sporangia are typically clustered into a sorus (pl., sori). A flap-like indusium arises along one edge of a sorus. The indusium forms a funnel around the sorus which is sunken in the leaf tissue. Each sorocarp consists of both a sorophore (stalk) and a sorus. Sorus in surface-view, magnified. The sorus forms directly from the zoospore nucleus. The sori lack true indusia, the base of the sorus bears a ring of scales. A sorus is able to produce gametes for the kelp. The sorus is light to dark brown and is called a bunt ball. In lichens and other fungi, the sorus is surrounded by an external layer. An envelope forms around the cluster of sporangia and the cluster becomes a sorus. For example, In place of ears of corn; plant-like sorus develop.