Another thank you in the direction of Robert Klips (aka Orthotrichum @Flickr) for sharing a small wonder. His photograph of Bryum argenteum was contributed via the UBC Botany Photo of the Day Flickr Pool. Appreciated as always.
I would suggest there are very few species visible to the naked eye–at most in the low dozens–that every single BPotD reader has encountered (been in proximity to at a reasonable distance) in his/her life. Among these highly successful species, though, is Bryum argenteum, the silvery bryum, silver-moss, or silvergreen bryum. Cosmopolitan in distribution, the species is found on every continent, e.g., Asia (Hong Kong and Yunnan), South America (Galapagos and Brazil), Africa (South Africa), Australia and Antartica.
The British Bryological Society’s British Mosses and Liverworts: A Field Guide entry for Bryum argenteum explains the habitat: “widespread and often abundant in disturbed habitats which may become very dry and are usually rich in nutrients such as nitrates. These include soil on and by paths (including cracks between paving slabs), roads, in arable fields, on waste ground and railway lines. It may also be found on stone rather than soil, as on walls, buildings, roofs, and concrete and tarmac”. Prior to such industrial developments, it was primarily a species of ecologically disturbed sites, such as sand dunes and eroding streambanks. UBC’s Biology 321 (Introduction to Bryophytes) class has yet more photographs of the species.
For local readers (and perhaps beyond?): there are still some spaces available in UBC Botanical Garden’s new Horticulture Training Program. I’ll be teaching one of the modules this year (or maybe I shouldn’t mention that–it might be a disincentive).