1. The stalk of a bryophyte sporo-phyte that supports the capsule. At maturity, the seta usually elongates rapidly, bearing the capsule to a height suitable for spore dispersal. A seta often contains vascular tissue, enabling the sporo-phyte capsule to obtain nutrients from the parent gametophyte. See also apophysis
2. A nervelike extension to a leaf, as seen in certain species of Selaginella.