A rolling stone may gather no moss, but that is about the only habitat in which these interesting plants will not be found. Indeed, they are common on trees, soil, cliffs, and non-rolling stones nearly everywhere. In most places, their presence is subtle: a thin green layer on tree bark, small clumps scattered along pathways and packed into sidewalk cracks, or high on blufftops out of the sight of trail-bound hikers. They can be conspicuous in places where trees, shrubs, grasses, wildflowers, and ferns are unable to thrive - typically on soil that is too thin, too dry, too wet, or too exposed to the erosive power of wind, water and weather. Their small physical stature (requiring a hand magnifier to perceive their leaves, stems, and matchstick-sized sporophytes and difficulty of identification (lacking birdbook-like field guides) contribute to their obscurity. I don't let that stop me from enjoying their beauty.
|Bryum in sidewalk crack|
|Anomodon on tree trunk|
|Leucobryum on sandy soil|
|On bedrock outcropping|
Always curious about mosses but burdened by the beginner's dilemma of lacking knowledge of how to develop a deeper understanding, I finally delved into the mystery by taking a "Bryophytes and Lichens" course offered by Dr. Jim Colbert at Iowa State University. Inspired, I started collecting mosses in 2007 as contributions to the Ada Hayden Herbarium to help build an understanding of their biodiversity in Iowa. My travels as a professional ecologist and as an avid kayaker on my personal time enabled me to visit a wide diversity of habitats across the breadth of the state. Although never having the time on these other-purposed trips to devote solely to moss-collecting, between 2007 and 2012, I nonetheless accumulated 112 specimens representing 46 species.
|...of Bryum argenteum|
|Trailside field inspection...|
Getting started in 2007, my first collection was plucked from the bark of a big bur oak in my own backyard: Lindbergia brachyptera, a moss commonly found on the trunks of deciduous trees. I later discovered that my very first collection actually preceded this one by eighteen years: out of curiosity back in 1989, I had collected a handful of moss forming a large, spongy mat on the edge of Ventura Marsh near Clear Lake, but forgot about it after donating it to the herbarium, where it resided undisturbed and unidentified in its original collecting bag for twenty-four years, finally rediscovered when I processed the rest of my collections in 2013. It turned out to be Amblystegium riparium, a common wetland moss.
Visiting the bluffs by kayak eliminates the need for a long off-trail hike from the nearest trailhead, but presents it own challenge of landing along sheer cliff faces. On several occasions, I have paddled to the base of the bluffs, climbed onto cliffs, and hauled my boat onto narrow ledges just above the waterline. The view of the lake from the cliffs is always inspiring and I have seen several mosses there, including Bryum caespiticium and Clasmatodon parvulus.
|Reboul's Liverwort (Reboulia hemisphaerica) on sandstone bluff|
Additionally, the liverwort Reboulia hemisphaerica is abundant here on shaded, north-facing outcrops. Intrigued by its purplish, leathery, rosette-forming thallus and its green-capped sporophytes, I took a sample and recorded it in my fieldbook as specimen #183.
|Close-up of fieldbook entry for collection #183|
The distinctive appearance of this striking liverwort made for a relatively easy tentative identification by me, but I nonetheless sought confirmation by a professional bryologist, Dr. William Zales (retired from Joliet College, Illinois and now residing in western Iowa). Armed with his positive identification, I created a final label for the envelope holding the specimen. Dr. Zales not only confirmed the identity of this specimen, he identified ALL of my moss and liverwort specimens! I deeply appreciate his contribution and have acknowledged him as the determiner ("Det:") on all of the labels. Thank you, Bill!
|Finished label for specimen #183|
Stimulated by his thoughtful identification of my whole collection, I spent several hours at my desk viewing the specimens with a stereoscope, creating a digital database, and generating final labels.
"Crouching next to a dolomite ledge, I peer through my hand lens at minute life-forms coloring the pitted rock surface: yellow-and-orange warts of sulfur firedot lichen, finely chiseled crusts of brown cobblestone lichen, black-dotted flakes of gray leather lichen, and coarse black clumps of Orthotrichum moss. Trapped in a perpetually drought-stricken habitat, this moss spends most of its time wrapped in bryological fetal position, its dark-bottomed leaves pulled protectively together as it endures intense heat and thirst. When wetted by passing rain, it explodes into photosynthetic action, instantly unfolding its artichoked leaves to reveal their green solar panels. I cannot resist the temptation: unscrewing the cap of my water bottle, I pour a dollop onto the clump. Watched through my lens, it immediately swells and twists to life like an awakened tarantula, quickly transforming from a dense black ball into a bright green bouquet of glistening leaves. But soon disappointed with the brevity of my rain, it slowly recurls and returns to dormant black limbo."
Though originally intended to serve as elements of the institutional memory of an herbarium, my mossy specimens evoke personal memories of the beauty of special places as well. For me, science and spirit are intertwined with memories of mosses.