Psilophytes

Psilophytes, also known as psilopsids or "early vascular plants," represent a group of extinct, primitive land plants that flourished in the Devonian period, approximately 400 million years ago. They are significant for being among the first plants to possess true vascular tissues, which allowed for more efficient transport of water and nutrients, and thus greater structural support and size compared to their bryophyte ancestors. Psilophytes were generally small, herbaceous, and lacked true leaves and roots as understood in modern plants. Instead, they had dichotomously branching stems, often with terminal sporangia where spores were produced. Their underground structures, rhizoids, served for anchoring and absorption, but were not as developed as modern root systems. The exact phylogenetic position of psilophytes is a subject of ongoing debate among paleobotanists, with some considering them a paraphyletic group ancestral to all other vascular plants and others placing them within or related to the extant whisk ferns (Psilotaceae). Fossils of psilophytes are found in ancient terrestrial sediments worldwide, providing crucial insights into the early evolution of plant life on Earth and the colonization of land. Their simple yet revolutionary vascular structure marked a pivotal step in the diversification of plant forms and ecosystems.