Equisetaceae
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Horsetail family🌿
Equisetaceae
トクサ科
A family represented solely by the extant genus Equisetum (horsetails). Tree-sized species once formed Carboniferous forests, but only herbaceous species survive today. Characterized by jointed stems with whorled branches and leaves. A spore-producing plant (seedless).
Key Characteristics
- ●Stems with distinct nodes; whorled branches at each node
- ●Leaves reduced to scale-like sheaths at the nodes
- ●Stems contain silica, making them rigid and abrasive
- ●Produce strobili (spore-bearing cones)
Phylogenetic Position
Vascular plants > Ferns > Equisetales > Equisetaceae
Divergence Era
Paleozoic Devonian (approx. 400 million years ago onward)
Representative Genera
トクサ属（Equisetum）
Related Evolution Events
- ・Thrived as tree-sized plants (over 30 m tall) during the Carboniferous
- ・Reduced to herbaceous forms only in the modern era