Stephani’s use of the “Sprucean” subgeneric names in Lejeunea, 1888-1893

Gradstein et al. (1982) propose to conserve four generic names of Lejeuneaceae: Lopholejeunea (Spruce) Schiffn., Acrolejeunea (Spruce) Schiffn., Trachylejeunea (Spruce) Schiffn. and Taxilejeunea (Spruce) Schiffn., each of which was introduced as a subgeneric name in Lejeunea by Spruce (1884), and subsequently raised to generic rank by Schiffner in his treatment of the Hepaticae in Engler-Prantl (preprint 1893) [see proposals to conserve 675-678 see p. 746]. Although Spruce (l.c.) used for his Lejeunea species a binary nomenclature by combining subgeneric names with specific epithets, it is clear (e.g. text, index) that the binomina are meant as Lejeunea combinations and they are considered as such by most authors (see Gradstein et al. for further details). Before 1893, however, the Sprucean subgeneric names were used in various papers by F. Stephani in a “seeming” generic rank; indeed Stephani now and then referred to them as “genus.” A chronological survey of a number of relevant papers by Stephani, mainly those published in Hedwigia, was given by Bonner et al. (1961), in conjunction with a brief discussion of the subject of this paper. These authors were the first to realize that on the basis of Art. 42 ICBN some generic names in Lejeuneaceae, e.g. Taxilejeunea and Trachylejeunea, can be considered as validly published by Stephani in Hedwigia 28, 1889. Later on Grolle (1979) demonstrated valid publication of monotypic new Lejeuneaceae genera by Stephani in the Bot. Gaz. 15, 1890, e.g. Lopho-Lejeunea and Acro-Lejeunea. For an evaluation of the status of Lopho- Lejeunea Steph., Acro-Lejeunea Steph., Trachylejeunea Steph. and Taxilejeunea Steph., one might consider these names against the background of the entire context of Stephani’s work on Lejeuneaceae until 1893. As the survey of Stephani’s papers in Bonner et al. is rather incomplete, and as there are several points of divergence in opinion, a new analysis of Stephani’s relevant papers (before Sep 1893) is presented below.