An extinct genus of seed ferns from the Paleozoic era characterized by cone-like reproductive structures.
From Greek 'kalamos' (reed) and 'stachys' (spike or ear of grain), referring to the reed-like stalks bearing spike-shaped seed organs that marked these ancient plants.
These 300-million-year-old plants bridge the evolutionary gap between ferns and seed plants, and scientists discovered them as fossils showing the exact moment plants learned to make seeds—one of evolution's greatest innovations.
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