Botany · Ch 2 — Plant Kingdom
Pteridophytes
Pteridophytes
Pteridophytes are considered the first true land plants and — crucially — the first plant group to evolve real vascular tissue (xylem and phloem), which is why they are also called 'vascular cryptogams'. Club mosses, horsetails, quillworts, water ferns and tree ferns all belong here. The group was already abundant back in the Devonian period of the Palaeozoic era, roughly 400 million years ago, and today's pteridophytes are mostly small, …
What this figure shows. Three photographs of living pteridophytes: (a) Lycopodium, a club moss with small scale-like leaves densely covering trailing or erect stems; (b) Equisetum, a horsetail with a jointed, ribbed stem and whorls of reduced scale leaves at each node; (c) Azolla, a small floating water fern forming a dense mat on …