Plant morphology share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany. Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive structures. The vegetative structures of vascular plants includes the study of the shoot system, composed of stems and leaves, as well as the root system. The reproductive structures are more varied, and are usually specific to a particular group of plants, such as flowers and seeds, fern sori,
Williamsonia (plant) Williamsonia (plant) Williamsonia is an extinct genus of plant belonging to Bennettitales, an order of seed plants which bore a resemblance to cycads. Fossilized specimens of "Williamsonia" have been discovered worldwide. "Williamsonia" was originally described as "Zamia gigas" by William Crawford Williamson. William Carruthers proposed the name "Williamsonia" in an 1870 paper of his, with the type species being "W. gigas". "Williamsonia" possessed a sturdy stem and had multiple fern-like leaves. The plant did not live in groups. The stamens of "Williamsonia" curved inward and upward. "Williamsonia" produced flowers up to in length. Its stalked seeds would have grown from