Frogs, sex, ancient plants and logarithms

The frogs have of late been involved in such frantic hochmagandie that the horsetails are lying in tatters on the local pond.

Horsetails Equisitum are ancient vascular plants that reproduce by spores rather than by seeds. Equisetum is the only remaining genus of a class of plants which was once much more diverse and which dominated the forests of the Carboniferous with some of the extinct species reaching to 30 meters tall.
It is sometimes claimed that the pattern of spacing of the nodes in the stems of horsetails, where those toward the apex of the shoot are increasingly closer together, was influential in the discovery of logarithms by John Napier (1550-1617) the Edinburgh mathematician.