Equisetum hyemale (toad-pipe) and Conocephalum salebrosum (cat’s tongue) and Adiatum pedatum (maidenhair fern, below) in deep Loess Hills ravines in late autumn. These species belong to some of the earliest plant taxa still in existence. Bryophytes (mosses and liverworts) were the first to evolve from aquatic plants, and pteridophytes (ferns, Equisetum and other spore-producing plants) appeared shortly thereafter in evolutionary time. Plants belonging to these groups are far older than seed-producing plants. Photos by Robert Smith in Fremont County, Iowa.
