Notes on American Musci

The variability of Papillaria nigrescens has already been emphasized by Steere (1934) and Bartram (1949). Even in the type specimen (S-PA) I found form and areolation of the leaves to be variable (fig. 1). This type material, moreover, proved to be provided with some filiform microphyllous branchlets, which is all the more noteworthy as the presence of microphyllous branchlets has sometimes been regarded as a diagnostic character of P. appressa. I examined a specimen sent to me on loan by the Munich Herbarium; it has been labelled in an old handwriting: “Hypn. appressum Hrsch. Minas Geraes” and in pencil was added: “Neckera appressa CM v. Muell. II, 136”; some distance apart from this was written; “An C. Müller”. I suppose that this must be the type material, or at least pârt of it, as this species was as far as I know only once again, and at a much later date, collected in Minas Geraes (Wainio, Brotherus, 1891). I choose this specimen as lectotype. The material consists of a few stems with some branches and a very small number of microphyllous branchlets. In the original description by Hornschugh (1840) nothing is said on these branchlets. Mueller (1851) does not mention their presence either. He states that P. (Neckera) appressa is very similar to P. nigrescens but that the stems are thicker and of a different colour and that the leaves are wider. In a note he writes: “Sterilis nota quidem, sed a N. nigrescente foliis certe distans”. He saw only the type specimen of Martius from Minas Geraes, probably the material cited above. Mitten (1869) is the first who mentions: “apicibus ramusculis filiferis”. He cites several specimens, including that of Martius and states at the end of the description: “A M(eteorium) nigrescente foliis latioribus acumine breviorem dorso minus distincte plicatis recedit”. There is indeed a rather striking difference in shape between typical leaves of the two type specimens (fig. 2 and 3).