Pilotrichaceae Kindb.

The Pilotrichaceae are a diverse and predominantly neotropical family traditionally placed in the order Hookeriales. Historically it has been treated as a small family with members mainly occurring on tree trunks (Brotherus 1925). In recent decades the family concept has been expanded considerably, in part by Buck (1998), to include as many as 21 genera (Goffinet et al. 2009) that are distributed mainly in the Neotropics, with fewer taxa in West Africa, and fewer still in Asia and the Pacific (the last being mostly outlying members of large genera). The best known genera are arguably Cyclodictyon, Callicostella, and Pilotrichum.

Only one species, Cyclodictyon blumeanum, is recorded the N.Z. Botanical Region from the Kermadecs archipelago, where it forms waterlogged pendent curtains on deeply shaded, irrigated rock outcrops and in springs. It is unusual in our flora by having well-developed double costae; no sporophytes have been found here.

An additional single species of the widespread genus Callicostella, C. papillata, occurs widely in Asia and the Pacific and could conceivably be found in the Kermadec Is or in the extreme north of the North I.

No attempt is made here to provide a description of this diverse family. According to Goffinet et al. (2009) the family is characterised by strong double costae, usually unbordered leaves, and fringed calyptrae. Buck (1998) provided a treatment of the 16 genera occurring in the West Indies.

The eponymous Pilotrichum is predominantly and probably exclusively neotropical.