“knight’s plume moss”
How to recognize knight’s plume moss: Ptilium crista-castrensis grows in beautiful glossy yellow-green mats with stems pinnately branched and arching upwards to look like little plumes. The 2-3 mm leaves are falcate-secund (asymmetric with leaf tips pointing down) to almost bent into a circle. These leaves are plicate with a double costa which is sometimes hard to see with all the leaf folds. There are narrow decurrencies extending down the stem.
Where to find knight’s plume moss: Ptilium crista-castrensis grows on thin soil over rocks, on soil and logs, and tree bases. It is the only species in this genus and is found throughout the north temperate regions of the world in boreal areas.