The Web of Life (80-1) Hopping Horsetail Legs

 Hopping Horsetail Legs

HorsetailĀ is a living fossil in being a vascular plant that reproduces by spores, when all its relations have since moved onto seeds. But the spores that horsetails sport are not ordinary. Horsetail spores are especially uppity. They have hair-like elaters: moisture-sensitive protrusions.

These little legs are made of 2 layers. One is stiff. The other is a softer, sponge-like material that deflates when dry.

Because the 2 layers are bonded, 1 layer shrinks when the humidity drops, but not the other. This causes a tension that results in a springy leap.

Jumping up in the air lets a spore catch wind currents which may carry it considerable distances; a lively dispersal technique. Elaters are especially effective because winds often pick up with weather changes to lower humidity.