Flora of New Zealand Series

Type : Fissurina dumastii Fée

Description : Thallus crustose, epi− or endophloeodal, ecorticate or with a cortex of longitudinal hyphae. Photobiont green, Trentepohlia. Ascomata apothecia, immersed, lirellate, fissurine (only visible as brownish black thalline cracks or slits), straight to flexuose, entire or branched, concolorous with thallus. Exciple uncarbonised. Hymenium colourless, I−, 60–120 μm tall. Hamathecium of paraphyses, 1–2 μm thick. Asci 4–8-spored, Graphis -type. Ascospores hyaline, I+ violet, globose to ovoid, 3-septate to muriform, often halonate. Conidiomata pycnidia, immersed. Conidiophores type II (Vobis 1980). Conidia bifusiform, colourless, 4–6 × 1–1.5 μm.

Fissurina is a genus of c. 30 species (Staiger & Kalb 2004a) included in the family Graphidaceae (Staiger 2002; Eriksson et al. 2004; Pennycook & Galloway 2004). Several New Zealand taxa were early described in Fissurina (Knight & Mitten 1860; Krempelhuber 1876; Knight 1876, 1883) but were subsequently transferred to Graphis, Graphina or Phaeographina (Müller Argoviensis 1894; Hayward 1977; Galloway 1985a) following the spore-based generic concepts of Müller Argoviensis in vogue since the late 19th century. Using chemical, morphological, anatomical and molecular methods on a wide range of taxa and studying characters such as ascocarp structure, ascus structure, paraphysis-type, and ascospore type, the recent revisionary work of Staiger (2002) proposes a more natural division of the Graphidaceae, and the reinstatement of several older genera such as Fissurina. Staiger's account of Fissurina (Staiger 2002: 117–163) discusses 28 species. Eight species are here recorded from New Zealand, comprising taxa formerly placed in the genera Graphina, Graphis, Phaeographina and Phaeographis, though as with other graphidaceous genera, the genus is still very much under-collected and poorly known here and would certainly repay a modern study.