the seeds. Xerochasy is dehiscence that occurs upon drying, and hygrochasy is dehiscence that occurs upon wetting, the fruit being hygroscopic. Dehiscent fruits that are derived from one carpel are follicles or legumes, and those derived from multiple carpels are capsules or siliques. One example of a dehiscent fruit is the silique. This fruit develops from a gynoecium composed of two fused carpels, which, upon fertilization, grow to become a silique that contains the developing seeds. After seed maturation, dehiscence takes place, and valves detach from the central septum freeing the seeds. This is also known as shattering and can be important as a seed dispersal mechanism. This process is similar to anther dehiscence and the region that breaks (dehiscence zone) runs the entire length of the fruit between the valves (the outer walls of the ovary) and the replum (the persisting septa of the ovary). At maturity, the dehiscence zone is effectively a non-lignified layer between two regions of lignified cells in the valve and the replum. Shattering occurs due to the combination of cell wall loosening in the dehiscence zone and the tensions established by the differential mechanical properties of the drying cells. Sporangium dehiscence in bryophytes Endothecium tissue found in moss capsules functions in a similar way in dehiscence to the endothecium in the walls of anthers (see above). Sporangium dehiscence in ferns Many leptosporangiate ferns have an annulus around the sporangium, which ejects the spores. Eusporangiate ferns do not generally have specialized dehiscence mechanisms. Sporangium dehiscence in fungi and myxomycetes See also Abscission—separation of structures that leads to their loss Anthesis—the opening of flowers Elaters—structures that form inside a sporangium and aid in spore dispersal of horsetails, liverworts, and hornworts Loment—a type of fruit that breaks apart but is not dehiscent Schizocarp—a type of fruit that breaks apart and may or may not be dehiscent. References Bibliography Fruit morphology Plant physiology Plant morphology