sporophyll n : leaf in ferns and mosses that bears the sporangia [syn: sporophyl]

A sporophyll is a leaf that produces spores. Sporophylls are part of the diploid sporophyte generation, and the spores are produced by meiosis and will germinate to produce haploid gametophytes. The spores are born in sporangia, which can take various forms in different kinds of plants. The sporophylls themselves also vary greatly in appearance and structure, and may or may not look similar to the trophophylls--leaves which only undergo photosynthesis to produce sugars, never producing spores. In more primitive plants, such as lycophytes and ferns, the sporophylls and trophophylls are both green and photosynthesize, and usually look very similar to each other. In more advanced plants, such as seed plants--and a few unusual primitive plants such as Equisetum--the sporophylls and trophophylls are very different from each other. For instance, in pines the sporophylls are modified to form both the woody bracts of pine cones (often called "ovuliferous scales") as well as the smaller, non-woody bracts of the pollen cones. In flowers the sporophylls are even further modified, and are represented by the stamens and carpels.

Small foliaceous structures bearing the sporangia in brown algae of the genus Alaria are also called "sporophylls", though structurally they are quite different from the sporophylls of vascular plants.