van der Pluijm, A. & Siebel, H. N. 2017. Orthotrichum comosum new to the Netherlands and Northwest Europe. — Herzogia 30: 10–15.
Orthotrichum comosum is reported for the first time from the Netherlands. It was discovered in 2011 on a tree of Acer platanoides in a residential area of the city of Hilversum. It is still present there in 2017 and has spread very locally. The morphology, differentiation with O. tenellum, ecology and distribution in Europe are discussed. A drawing and a photograph of the specimen are provided. Recent decades of very mild winters in the Netherlands and the relatively hot and dry microclimate of inner cities could have favoured the establishment of this Mediterranean-montane epiphyte.