Archaeopteris

Archaeopteris is an extinct genus of large Devonian progymnosperms with woody trunks and fern-like leaves. It reproduced with spores rather than seeds.

Progymnosperm: An extinct group of vascular plants combining woody growth with reproductive features associated with seed plants. Archaeopteris is among the best-known members of this group.
Secondary growth: Growth that increases a plant stem's girth through lateral meristems, including the vascular cambium. Secondary growth produced the thick, woody trunk that supported Archaeopteris.
Middle Devonian: The middle epoch of the Devonian Period, spanning roughly 393 to 383 million years ago. Archaeopteris appeared during this interval as woody vegetation diversified.
Devonian period: A geological period from about 419 to 359 million years ago, marked by major diversification of fishes and land plants. Archaeopteris forests became a defining feature of Devonian terrestrial ecosystems.
Vascular plant: A plant with specialized tissues that transport water, minerals, and sugars through its body. Its conducting tissues enabled Archaeopteris to grow into a large tree.
Vascular cambium: A cylindrical meristem that produces secondary xylem inward and secondary phloem outward. Cambial activity built the wood and increasing trunk diameter of Archaeopteris.
Late Devonian: The final epoch of the Devonian Period, spanning roughly 383 to 359 million years ago. Archaeopteris became widespread and helped shape forests during this epoch.
Forest: A terrestrial ecosystem dominated by trees and other woody vegetation. Archaeopteris helped establish forests with extensive canopy and root systems.
Lignin: A complex polymer that strengthens plant cell walls and helps make wood rigid. Lignified tissues gave Archaeopteris durable, weight-bearing trunks.
Root system: The underground plant structures that anchor a plant and absorb water and minerals. Extensive roots helped Archaeopteris anchor large trunks and alter Devonian soils.

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