Flora of New Zealand Series

=PHLYCTELLA Kremp., 1876

Type : Peltigera agelaea (Ach.) Wallr. [=Lichen agelaeus Ach. =Phlyctis agelaea (Ach.) Flot.]

Type : Phlyctella abstersa Kremp. [=Phlyctis subuncinata Stirt.]

Description : Flora (1985: 385 – as Phlyctella Kremp.).

Phlyctis, a genus of c. 20 species worldwide (Tønsberg 2004d), is accommodated in the family Phlyctidaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005). Hawksworth & Sherwood (1981: 345) detail nomenclactural problems surrounding the application of the name Phlyctis, recommending conservation in its present sense, the proposal later being accepted (Korf 1988: 452). In the Flora treatment (Galloway 1985a: 385–389) species of Phlyctis were referred to Phlyctella Kremp., a later synonym of the genus. Later, Galloway & Guzmán Grimaldi (1988: 396) indicated that thalline and apothecial characters are similar in both genera; that species of both genera have a well-defined chemistry consisting of one or more of the following depsidones: stictic, constictic, norstictic, connorstictic, hypostictic, salazinic, psoromic, neopsoromic or protocetraric acids; and that both genera have a protococcoid photobiont. Ascospores in Phlyctis are colourless, fusiform or oblong–ellipsoidal, septate and 8 per ascus, although a New Zealand species P. megalospora P.James (Galloway 1983a, 1985a) has very large ascospores that are oblong–ellipsoidal, 17–23-septate, and 1 per ascus. In contrast, Northern Hemisphere species of Phlyctis, Phlyctomia and Phlyctidia have ascospores that are oblong–ellipsoidal, 1–2 per ascus and muriform or many-septate (Massalongo 1860; Fries 1871; Müller Argoviensis 1895; Zahlbruckner 1926: 227–228; Fink 1935: 315–316; Poelt 1969). It was concluded that taxa included in Phlyctomia, Phlyctella and Phlyctidia should all be accommodated in the older genus Phlyctis, since the major difference between them was only one of ascospore septation, scarcely a valid diagnostic generic character. It was also noted that the terricolous, monospecific genus Psathyrophlyctis Brusse from Cape Provice, South Africa, which has colourless, muriform ascospores (35–45 × 17–18.5 μm), 1–2 per ascus (Brusse 1987), is likely also to be closely allied to Phlyctis.

In the Southern Hemisphere, species of Phlyctis grow directly on bark or over bryophytes on bark where their smooth, white or pale grey-white or green-white thalli resemble bands or splashes of "white paint", an easy means of identifying the genus. Apothecia are usually small, innate or subimmersed and often clustered, the discs being commonly white-pruinose, which makes them often difficult to recognise apart from the thallus. Phylctis has its greatest species diversity in cool temperate rainforest vegetation in New Zealand where at present six species are recorded, although at least two undescribed, large-spore species are known and the genus would amply repay a critical study. Five species are endemic to New Zealand, one is Australasian (Kantvilas & James 1991; Filson 1996; McCarthy 2003c, 2006), and additional taxa are known from Chile, tropical South America, and India (Vainio 1890; Zahlbruckner 1928; Galloway & Guzmán Grimaldi 1988; Galloway & Quilhot 1999).