Spermatophyte plants that have unenclosed, "naked seeds": The fifth extant division is the flowering plants, also known as angiosperms or magnoliophytes, the largest and most diverse group of spermatophytes. Angiosperms possess seeds enclosed in a fruit, unlike gymnosperms. In addition to the taxa listed above, the fossil record contains evidence of many extinct taxa of seed plants. The so-called "seed ferns" (Pteridospermae) were one of the earliest successful groups of land plants, and forests dominated by seed ferns were prevalent in the late Paleozoic. "Glossopteris" was the most prominent tree genus in the ancient southern supercontinent of Gondwana during the Permian
Evolutionary history of plants is not a viable food source for fungi, herbivores or detritovores, so is prone to preservation. It is also robust, so can withstand pressure and display exquisite, sometimes sub-cellular, detail. All multicellular plants have a life cycle comprising two generations or phases. The gametophyte phase has a single set of chromosomes (denoted 1"n), and produces gametes (sperm and eggs). The sporophyte phase has paired chromosomes (denoted 2"n), and produces spores. The gametophyte and sporophyte phases may be homomorphic, appearing identical in some algae, such as "Ulva lactuca", but are very different in all modern land plants, a condition known as