A Really Nice Present

My wife brought me a very impressive frond of Equisetum, commonly known as Horsetails, from her trip through Humboldt and Mendocino Counties.  Horsetails are a relic of the distant past, a dominant plant during the age of dinosaurs.  The timing of this gift was perfect because earlier in the day I had listened to Science Friday on NPR and the guest was a biologist/photographer who had just come out with a book called Relics: Traveling in Nature's Time Machine which focused on plant and animal  relics that give us a sense of "deep time."  The first one of these I became aware of was the Horseshoe Crab, a prominent feature of my youthful explorations of beaches around Plymouth, Massachusetts.
Horsetails will send up both fertile and sterile fronds from their root systems. The sterile fronds have branches which are miniature versions of the main stem and are segmented in a way that vaguely resembles bamboo.  To the original namers, they resembled horse's tails.  Pictured above is a fertile front with the biggest sporangium I've ever seen.  The squares on the graph paper are 1/2".  Within seconds of taking the top photo, I noticed a "puddle" of blueish green underneath.  I moved the plant aside to reveal a pile of tiny spores, each one of which contains the "information" needed to grow more Horsetails. The stems of these plants have such a high silica content they can function like sandpaper.  They can come in handy for cleaning pots used to cook over a campfire.  In this context they are often known as Scouring Rush.