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How does humidity affect the coiling and uncoiling of horsetail spore elaters?
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Equisetopsida
Giant horsetail of Europe (Equisetum telmateia).
The spores of horsetails (Equisetum) possess four appendages known as elaters. These structures are highly sensitive to moisture and function by coiling and uncoiling in response to changes in humidity. This movement is a critical mechanism that assists in the dissemination of the spores.12