Pollen calendar Pollen calendar A pollen calendar is used to show the peak pollen times for different types of plant pollen, which causes allergic reactions in certain people. A pollen calendar can be a very useful tool in forensic science, because it can be used to place the month, or week, or date of death. The use of pollen for criminal investigation purposes is called "forensic palynology". However, the use of a pollen calendar to set the date of death should be used with extreme caution, and only by a carefully trained expert witness. The CSI effect has put pressure on some
Annulus (botany) dissolve to allow the cap to fall off and the spores to be released. Annulus (botany) An annulus in botany is an arc or a ring of specialized cells on the sporangium. These cells are arranged in a single row, and are associated with the release or dispersal of spores. In leptosporangiate ferns, the annulus located on the outer rim of the sporangium and serves in spore dispersal. It consists typically of a ring or belt of dead water-filled cells with differentially thickened cell walls that stretches about two-thirds around each sporangium in leptosporangiate ferns. The thinner walls on the