Plagiochilaceae, Muller, 1956

Söderström, Lars, Hagborg, Anders & Konrat, Matt Von, 2015, Notes on Early Land Plants Today. 69. Circumscription of Plagiochilaceae (Marchantiophyta) with a preliminary infrageneric subdivision of Plagiochila, Phytotaxa 208 (1), pp. 75-91 : 75-76

Circumscription of Plagiochilaceae

The family Plagiochilaceae Müller (1956: 877) was originally circumscribed to include the genera Mylia Gray (1821: 693) , Pedinophyllum ( Lindberg 1874: 366) Lindberg (1875: 504) and Plagiochila ( Dumortier 1831: 42) Dumortier (1835: 14) . Mylia was transferred to Jungermanniaceae by Grolle (1962) forming a new subfamily, subfam. Mylioideae Grolle (1962: 15) , which was later elevated to its own family, Myliaceae Schliakov (1975: 308) . Later, several genera, mostly segregates from Plagiochila were established and referred to the family. Crandall-Stotler et al. (2009) included Acrochila Schuster (1963: 285) , Chiastocaulon Carl (1931a: 58) , Dinckleria Trevisan (1877: 421) , Pedinophyllopsis R.M.Schust. et Inoue in Schuster & Engel (1981: 311), Pedinophyllum , Plagiochila , Plagiochilidium Herzog (1931: 186) , Plagiochilion Hattori (1947: 7) and Xenochila Schuster (1959a: 15) . Söderström et al. (2013) moved the genus Pseudolophocolea R.M.Schust. et Inoue in Schuster & Engel (1982: 71) from Lophocoleaceae Vanden Berghen (1956: 208) to Plagiochilaceae . Plagiochilaceae is related to Lophocoleaceae and several genera have shifted positions between the families. Other genera that have been included in Plagiochilaceae in various publications are either synonyms with any of the mentioned genera, or now included in other families. In addition to Plagiochila , the following genera are now recognized within the family.

Acrochila was established to accommodate Acrochila simpsonii (W.Martin & E.A.Hodgs. in Martin 1950: 497) Schuster (1963: 285) [= Acrochila biserialis (Lehm. et Lindenb. in Lindenberg 1843: 126) Grolle (1964a: 236)] and Acrochila etesseana ( Stephani 1908: 152) Schuster (1963: 285) [= Acrochila caledonica ( Stephani 1908: 32) Inoue 1967: 182 ], two segregates from Plagiochila . The genus was included in the molecular study of Groth (2005) with conflicting results. One marker placed it in Plagiochilaceae and another marker as a sister to Adelanthus Mitten (1864: 243) . However, we here retain it in Plagiochilaceae until further studied.

Chiastocaulon was established to accommodate Chiastocaulon dendroides ( Nees 1830: 77) Carl (1931a: 59) , Chiastocaulon flagelliferum Stephani (1918: 155) Carl (1931a: 60) and Chiastocaulon minutifolium Stephani (1921: 185) Carl (1931a: 60) . All three species were united to one species by Dugas (1929) who considered it a Plagiochila species. This view was followed by most authors until Groth & Heinrichs (2003) in a molecular study showed it to be distinct from Plagiochila .

Dinckleria was established to include only one species, Dinckleria pleurata ( Hooker & Taylor 1844a: 372) Trevisan (1877: 421) . This name had generally been synonymized with Plagiochila until the new genus Proskauera Heinrichs et J.J.Engel in Heinrichs et al. (2006: 235) was described with two species, Proskauera pleurata (Hook. f. et Taylor) Heinrichs et J.J.Engel in Heinrichs et al. (2006: 235) and Proskauera fruticella ( Hooker & Taylor 1844c: 565) Heinrichs et J.J.Engel (2006: 237) overlooking the older name Dinckleria . This was corrected in Engel & Heinrichs (2008). The close relationship to Plagiochila and inclusion in Plagiochilaceae has never been challenged.

Pedinophyllopsis was established to accommodate Pedinophyllopsis abdita ( Sullivant 1850: 317) R.M.Schust. et Inoue in Schuster & Engel (1981: 311). It was originally placed in Geocalycaceae , but it was noted to be a very isolated in the family and He-Nygrén & Piippo (2003) showed that it is better placed in Plagiochilaceae .

Pedinophyllum was established to accommodate Pedinophyllum pyrenaicum ( Spruce 1847: no. 9) Lindberg (1875: 504) [= Pedinophyllum interruptum ( Nees 1833: 165) Kaalaas (1893: 190) ] and now includes four species (although some not universally recognized). Although recognized as close to Plagiochila its position within Plagiochilaceae has sometimes been questioned, but Feldberg et al. (2010 b) showed it belongs there.

Plagiochilidium was described with one species, Plagiochilidium borneensis Herzog (1931: 186) [= Plagiochilidium bidentulum ( Stephani 1905e: 1134) Grolle (1988: 408) ]. It was described as closely related to Jamesoniella ( Spruce 1876: 230) Carrington (1881: 25) and originally placed in Lophoziaceae Cavers (1910: 293) together with Plagiochila . Buch et al. (1937) then transferred it to Plagiochilaceae .

Plagiochilion was originally established to include two species, Plagiochilion oppositum ( Reinwardt et al. 1824: 226) Hattori (1947: 7) and Plagiochilion braunianum ( Nees 1830: 80) Hattori (1947: 7) in the Plagiochilaceae . Later, several other species have been referred to the genus. Fourteen species are recognized at present.

Pseudolophocolea was established to accommodate Pseudolophocolea denticulata Schuster & Engel (1982: 73) . It was originally described as being closely related to Pedinophyllopsis . The authors even speculated that the two genera might be regarded as subgenera of a single genus. Although both genera were placed in Geocalycaceae subfam. Leptoscyphoideae Schuster (1980: 267), an affinity with the plagiochiloid Pedinophyllum was also noted. He-Nygrén & Piippo (2003) showed that Pedinophyllopsis is best placed in Plagiochilaceae , a hypothesis further supported by the molecular studies of Groth (2005). Based on the morphological similarities of Pseudolophocolea with Pedinophyllopsis and Pedinophyllum detailed in Schuster & Engel (1982), Pseudolophocolea was placed in Plagiochilaceae by Söderström et al. (2013).

Xenochila was established to accommodate Xenochila paradoxa ( Stephani 1921: 197) Schuster (1959a: 15) [= Xenochila integrifolia ( Mitten 1861: 96) Inoue (1963: 373) ]. It was assumed to be related to Plagiochilidium by Inoue (1963).