​ACOTYLEDONES, the name given by Antoine Laurent de Jussieu in 1789 to the lowest class in his Natural System of Botany, embracing flowerless plants, such as ferns, lycopods, horse-tails, mosses, liverworts, sea-weeds, lichens and fungi. The name is derived from the absence of a seed-leaf or cotyledon. Flowering plants bear a seed containing an embryo, with usually one or two cotyledons, or seed-leaves; while in flowerless plants there is no seed and therefore no true cotyledon. The term is synonymous with Cryptograms, by which it was replaced in later systems of classification.