Spring 2015 Volume 6, Issue 1 From the Ground Up A Gardening and Native Plants Quarterly Colorado State University Extension-Pueblo County 701 Court Street · Suite C · Pueblo, CO 81003 · 719-583-6566 ·
[email protected] FABULOUS FAMILIES FERNS by Ed Roland, Native Plant Master, 2009 Most ferns inhabit cool, moist canyons in this part of Colorado, but their habitats range from arid deserts to north of the Arctic Circle. They can be found as epiphytes ("air plants" without a true root system) in the canopy of a tropical rain forest, or as tiny water-borne species in salt-water lagoons. Tree ferns, reaching over 80 feet into the air with 15-foot fronds, grow into dense thickets in many tropical habitats. With fossils dating back to the Devonian (c. 400 MYA), ferns are viewed by paleobotanists as critical pioneer species in the development of our modern ecologies. For example, the fossil record shows that ferns dominated for millions of years after an estimated 6-mile diameter asteroid impacted the earth (at the end of the Cretaceous about 65 million years ago), making it impossible for most seed-bearing plants to survive. Long before that, ferns were so prevalent that they are the primary components of our coal deposits. While some species of ferns in lower elevations take on a morphology more akin to a grass or clover, what I'm describing here are the "true ferns" we're more likely to encounter in our higher elevation mountain drainages. These ferns have the compound leaves we call "fronds." Fronds are typically dissected into "pinnae" and, if bi-pinnately compound, then "pinnules." (See Photo A.) With an estimated 12,000 plus species world-wide, the vast majority of which are true ferns in the phylum (or, for botanists, "division") Filicinophyta, ferns are by far the most diverse of the Photo A: Section of a bi-pinnately compound Male seedless plants.