04/26/2025
The Pacific Northwest is home to an incredible diversity of mosses—over 500 species in Oregon and Washington! Many different species can be found growing side by side. Some mosses have subtle differences that take a keen eye (and often a hand lens) to spot, while others stand out with unique textures or colors.
Club mosses (like the Lycopodium clavatum, shown in a close up in the second photo) may look similar, but they’re actually ancient vascular plants. Club mosses have specialized tissues for moving water and nutrients, and despite their name, they’re more closely related to ferns than to true moss. Unlike mosses, vascular plants (like trees, wildflowers, ferns and club mosses) have roots, stems, leaves, and often produce seeds or flowers (though not always, as we have just learned from our buddy Lycopodium). Bryophytes (mosses, liverworts and hornworts), on the other hand, absorb water/nutirents directly through leaves and structures called rhizoids that superficially resemble roots, but do not connect to vascular structures like xylem and phloem.
Here are a few of the species we’re using as teaching specimens for Plant Systematics at PSU, which have since been happily relocated to my office (their terrarium can be seen in the last photo). If you’d like to start identifying local mosses in western Oregon and Washington—as well as an all-around great book for getting to know plants west of the Cascades—Pojar’s “Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia and Alaska” is a great entry point, and required reading for the class.
