1. Any dry dehiscent fruit derived from two or more many-seeded fused carpels (see illustration at fruit). Capsular fruits are classified by the nature of dehiscence and the number of carpels in each fruit. For example, if dehiscence is along the dorsal suture the capsule is loculicidal, as in willow herbs (Epilobium), and if along the septa, septicidal, as in St John's worts (Hypericum).
2. The structure containing the spores of the *sporophyte
generation in mosses, liverworts, and ferns, the wall of which may be uni- or multicellular. The capsule is borne on the end of a stalk and may rupture by a variety of mechanisms.
3. A transparent layer of gelatinous or mucilaginous material that envelops some bacterial cells. The polysaccharides of the capsule are often characteristic of a species. Polypeptides may also be present. In some species the capsules hold together a number of bacteria, forming a structure termed a zoogloea.