An illustration of a fossil of a toothed fern. Ferns are vascular plants differing from the more primitive lycophytes by having true leaves (megaphylls), and they differ from seed plants (gymnosperms and angiosperms) in their mode of reproduction — lacking flowers and seeds. Like all other vascular plants, they have a life cycle referred to as alternation of generations, characterized by a diploid sporophytic and a haploid gametophytic phase.

Leaf Indentations

An illustration of a fossil of a toothed fern. Ferns are vascular plants differing from the more primitive…