The genus Farlowiella Sacc.
Syll. Fung. IX: 1101 (1891)
by Eric W.A. Boehm
Farlowiella carmichaeliana (Berk.) Sacc. From top left: Dennis (1978), Ellis & Ellis (1985); below: Zogg (1962).
Farlowia Saccardo, 1883
The genus Farlowiella Sacc. is characterized by one-celled pedicellate slightly laterally compressed amerospores, the upper cell pigmented & much larger than the lower, which remains un- or less-pigmented, and can be considered as an associated papilla. The carbonaceous hysterothecia are somewhat laterally compressed, but nonetheless thick-walled and with a prominent sunken slit. They can be solitary to gregarious, but remain erect, and elevated, presenting an almost stipitate appearance. Anamorphs have been described in the genus Acrogenospora (Goh et al. 1998). Two species have been described, namely F. carmichaeliana (Berk.) Sacc. from Europe (England, Belgium, Switzerland), collected from the bark and wood of Fagus, Quercus, Sorbus and Prunus, and F. australis Dennis, known only from the original collection on Phylica arborea from Tristan da Cunha in the South Atlantic (Dennis 1955).
Recent sequence data (Boehm et al. 2009; Schoch et al. 2007) obtained from F. carmichaeliana (Berk.) Sacc. (CBS 206.36) indicate that this taxon lies quite distant from both the Hysteriaceae and the Mytilinidiaceae, but remains firmly within the Pleosporomycetidae (Figs. 2 & 3). The genus Farlowiella was therefore removed from the Hysteriaceae (Boehm et al. 2009) and placed as gen. incertae sedis until such time that more isolates could be examined. However, this was based on only a single isolate, and more studies are needed to confirm the phylogeny of the genus Farlowiella.
Key to the species of Farlowiella Sacc.
- Ascospores unequal two-celled; upper cell pigmented, much larger than lower cell; lower cell hyaline, smaller, subtending larger upper cell; measuring 18 – 21 x 7 – 12 μm; European → F. carmichaeliana (Berk.) Sacc.
1′. Ascospores as above, but small and measuring 13 – 15 x 6 – 7.5 μm; Tristan da Cunha → F. australis Dennis