Trichomanes dregei, Bosch (van den Bosch, 1858

Dubuisson, Jean-Yves, Nivart, Adele, Senterre, Bruno & Rouhan, Germinal, 2021, New taxonomic treatment for Trichomanes parvulum Poir. and T. dregei Bosch (Hymenophyllaceae, Polypodiidae), Phytotaxa 523 (1), pp. 119-125 : 123

Trichomanes dregei

Trichomanes dregei , described on the basis of South African specimens, is listed by Roux (2009) as synonym for Abrodictyum rigidum ( Swartz 1788: 137) Ebihara & Dubuisson ( Ebihara et al. 2006: 243) . But the latter species is strictly Neotropical and the Afro-Malagasy populations actually represent the distinct taxon A. pseudorigidum Bauret & Dubuisson ( Dubuisson et al. 2016: 161) .

Van den Bosch (1858) named T. dregei the South African specimens collected by Drège as cited by Kunze (1836) under T. rigidum , hence the Roux’ treatment. However, neither van den Bosch (1858) nor Kunze (1836) accompanied the new name and citation of occurrence with a precise description. This explains that T. dregei had been erroneously treated as a nomen nudum in the synonymy of A. pseudorigidum ( Dubuisson et al. 2016) . This resulted from the oversight of an additional Kunze’s observation (p. 554) clearly mentioning a few morphological differences between Drège’s specimens and the Neotropical populations. As such, this observation should be considered as an effectively published diagnosis, to which van den Bosch (1858) made a reference and thus validated the name T. dregei (Art. 38.1(a), Turland et al. 2018). Since T. dregei is the earlier name, its specific epithet has priority over pseudorigidum and must therefore be combined under Abrodictyum C.Presl ( Presl 1843: 20) .