Note on the occurrence of Metzgeria saxbyi Pearson in southern Africa

Metzgeria saxbyi was originally described by Pearson (1931), based on material collected by H.H. Saxby in Ghana in 1910. Sim (1926) regarded the monoicous South African plants of Metzgeria as M. conjugata Lindb., a species resembling M. saxbyi, but not known from Africa (So, 2004; Wigginton, 2004b, 2009). Metzgeria saxbyi was first reported as occurring in South Africa and Swaziland by S. Arnell (1963), based on material which was originally identified as M. furcata (L.) Dumort. The material was collected in Swaziland: Horo Forest, 2531CB, April 1932, V.A. Wager 108 (PRE) and in South Africa: Cape Town, Table Mountain, Skeleton Gorge, 3318CD, January 1916, J.W. Bews PRECH8489 (PRE). The species was subsequently included in a series of southern African checklists up to Perold (2003) and neatly illustrated by O. van Kerckhove (in Wigginton 2004b: 94, Figure 56). Perold (2006) excluded the species from her latest checklist of South African liverworts and cited So (2004) and Wigginton (2004a). However, So (2004) did not actually exclude M. saxbyi from South Africa and Swaziland but did not see specimens from this region. Wigginton (2004a, 2009) did not include southern Africa in the distribution of Metzgeria saxbyi and noted that its occurrence in these countries needs confirmation. Sterile material of Metzgeria can be easily misidentified as characters like costal cortical cells and hair placement and presence occur sporadically. Marginal and costal hairs are a difficult character to use when the material is very old as these get broken with age. However, M. saxbyi is the only monoicous species in Africa (So, 2004; Wigginton, 2004b). The southern African specimens listed above were examined and found to be monoicous, the most important character used in identifying M. saxbyi. The occurrence of this species in South Africa as well as Swaziland is therefore confirmed.