Notes on Early Land Plants Today. 26. Miscellaneous synonyms in liverworts (Marchantiophyta)

Aneura bipinnata (≡ Riccardia bipinnata, described from Jamaica as Jungermannia bipinnata (“2-pinnata“) by Olof Swartz (1788, 1806), is one of the oldest names in Aneuraceae and one of the poorest known. Swartz' original description and the brief diagnosis in Synopsis Hepaticarum (Gottsche et al. 1846) are the only available descriptions for the species. Stephani (1899) was unable to locate material of Aneura bipinnata and listed the species without description in his Species Hepaticarum. Swartz (1806) compared his Jungermannia bipinnata with Jungermannia multifida (≡ Riccardia multifida), a widespread Holarctic species. My study of the holotype material of Jungermannia bipinnata kept in S revealed that the species is identical to R. multifida and a synonym of the latter. Characteristic are the creeping to somewhat procumbent, several cm long shoots with regularly 2(-3)-pinnate branching, the linear, broadly winged branches and the swollen, biconvex main axis with or without a narrow wing. The Swartz collection constitutes the only known record of R. multifida from Jamaica (Söderström et al. 2011) and from the Caribbean as a whole. A field search should therefore be undertaken to confirm its occurrence on Jamaica. At the same time, efforts should be made to confirm the occurrence in Jamaica of Riccardia palmata (Hedwig 1784: 87) Carruthers (1865: 302), a Holarctic species that is not known from the tropics with certainty except from Mexico. Like R. multifida, R. palmata was collected on Jamaica by Swartz (1788, 1806) and never afterwards. Unfortunately, the Jamaican material of R. palmata (originally described as Jungermannia polyphylla Swartz 1788: 145) could not be found in S. A plant with flabellate branching from southern Brazil was described by Nees (1833) as Jungermannia bipinnata β flabellifera. This plant clearly differs from Riccardia multifida by having a stoloniform main axis giving rise to erect, irregularly pinnate to flabellate branches, and is similar to Riccardia regnellii. The latter is a rather common and characteristic species of the Atlantic rain forests of eastern and southern Brazil, ranging from Pernambuco to Rio Grande do Sul (Gradstein & Costa 2003).