Palaeozoic Life possesses an individuality not less distinctly marked than that of the group of strata, which demarcates it very sharply from the life of succeeding periods, and gives a certain unity of character to the successive assemblages of plants {floras) and of animals {faunas). The era is remarkable both for what it possesses and what it lacks. Among plants, the vegetation is made up principally of Cryptogams, seaweeds, ferns, club-mosses, and horsetails. Especially characteristic are the gigantic, tree-like club-mosses and horsetails, which are now represented only by very small, herbaceous forms. The only flowering plants known are the Gymnosperms, the Cycads, and their allies; no Angiosperms have been discovered. Palaeozoic forests must have been singularly gloomy and monotonous, lacking entirely the bright flowers and changing foliage of later periods.