Pseudocyphellaria Vain.
Type: Pseudocyphellaria aurata (Ach.) Vain. [=Sticta aurata Ach.]
Description : Thallus heteromerous, foliose, dorsiventral, lobate, often very large, orbicular, or irregularly laciniate, or ±dichotomously branched, to complexly entangled, rarely ±monophyllous, loosely to closely attached. Lobes very variable, narrow, strap-like, ±dichotomously branching with distinctly bifurcating apices that may be pointed, blunt or rounded, to complex-imbricate. Margins entire or variously incised, notched or folded, often markedly thickened below, often with conspicuous, elongated or verruciform-conical or glomerulate pseudocyphellae, often free and ascending, thick and coriaceous to thin and fragile, with or without soredia, isidia or phyllidia. Upper surface smooth, wrinkled, ±scabrid or hairy, often deeply or shallowly faveolate, with faint or strongly marked reticulum of interconnecting ridges, ridges shallowly rounded to sharply defined, glossy, matt or dull, often conspicuously maculate (×10 lens, maculae best seen when wet), with or without isidia, pseudoisidia, phyllidia, pseudocyphellae or soredia. Medulla white or yellow. Photobiont green (Dictyochloropsis or Chlorella -like) or cyanobacterial (Nostoc), sometimes both green algal and cyanobacterial dominated lobes growing intimately together (photosymbiodemes) and united by the same fungus. Internal cephalodia containing Nostoc in taxa with a green photobiont, often visible as swellings on the lower surface. Lower surface glabrous in some taxa but usually ±tomentose, tomentum pale to dark, thick, felted to indistinctly pubescent. Pseudocyphellae always present, white or yellow, sparse to frequent, ± immersed in tomentum, plane and ±fleck-like to raised-conical, verruciform or glomerulate, round to irregular, limits distinct or indistinct.
Ascomata apothecia, hemiangiocarpic, sessile to pedicellate, laminal or marginal, rounded, margins entire or crenate-striate to ±stellate, with or without phyllidia, isidia or soredia, disc matt or glossy, sometimes white-pruinose, thalline exciple in taxa with pedicellate ascomata, smooth to verrucose or scabrid-areolate, hairy, sorediate or maculate; proper exciple in taxa with sessile ascomata, smooth to verrucose or scabrid-areolate or tomentose. Hymenium I+ blue, colourless. Hamathecium of simple, septate, filiform paraphyses, swollen, occasionally ±moniliform and often pigmented at apices, epithecium present or absent, often pigmented and becoming coloured in K. Asci cylindrical or clavate, apex with an I+ blue ring. Ascospores 8 per ascus, uniseriate or biseriate, colourless to yellow-brown, fusiform-ellipsoidal to broadly ellipsoidal, rarely acicular-fusiform, apices rounded or pointed, simple at first, becoming 1–3-septate at maturity, sometimes 2-celled spores have strongly thickened walls with a narrow central canal connecting the locules.
Conidiomata pycnidia (Lobaria -type), immersed, ±globose, visible as slight swellings on upper surface and occasionally on lower surface, ostiole dark red-brown to black, plane, elevated or punctate-depressed, randomly scattered or in lines at margins and on thalline ridges, most common towards lobe apices, often eroding and leaving gaping pits. Conidiogenous cells colourless, ±cuboid, phialidic, on simple to slightly branched conidiophores, bearing conidia laterally and terminally. Conidia short, colourless, bacillar to slightly dumbell-shaped.
Chemistry diverse, containing depsides, depsidones, terphenylquinones, pulvinic acid derivatives and triterpenoids of hopane, fernene, stictane, seco-stictane or lupane series.
Key
Pseudocyphellaria is a cosmopolitan genus of c. 115 taxa included in the family Lobariaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005), and is characteristic of humid, cool-temperate habitats in the Southern Hemisphere where it is most highly speciose. Major areas of species diversity are New Zealand (48 species), southern South America (54 species), Australia (39 species) and the palaeotropics (29 species). It is now recognised that Pseudocyphellaria as currently defined (see also Galloway & Laundon (1988) and above) is polyphyletic (Thomas et al. 2000, 2002; Miadlikowska et al. 2002; Stenroos et al 2003; Wiklund & Wedin 2003; Miadlikowska & Lutzoni 2004) and that the white-medulla taxa (with hopane triterpenoids) form a separate and distinct clade from Pseudocyphellaria s. str., which is characterised by a yellow medulla and fernene triterpenoids. However, as the taxonomic status of the various clades within Pseudocyphellaria s. lat. are still not completely resolved, taxa are maintained here as Pseudocyphellaria s. lat., although it is recognised that at least three generic entities are accommodated within this circumscription. Molecular studies currently in progress will hopefully allow the status of the various observed clades to be more closely defined. Chemistry in Pseudocyphellaria s. lat. is discussed in Wilkins & James (1979), Galloway (1988a, 1991b), Wilkins & Elix (1990), Wilkins (1993), Perry et al. (1999) and Galloway et al. (2001b). Lichenicolous fungi are commonly associated with species of Pseudocyphellaria (Wedin 1993b, 1994; Kondratyuk et al. 1994; Kondratyuk & Galloway 1995a; Wedin & Kondratyuk 1997; Wedin & Hafellner 1998; Ertz et al. 2005) with the following genera of lichenicolous fungi known from New Zealand species : * Arthonia (q.v.), * Arthrorhaphis grisea (q.v.), * Corticifraga (q.v.), * Dactylospora (q.v.), * Lichenoconium (q.v.), * Perigrapha (q.v.), * Plectocarpon (q.v.), * Pyrenidium (q.v.), * Scutula (q.v.), * Stigmidium (q.v.) and * Wentiomyces (q.v.). Much interest in recent years has centred on the photobiont versatility of several species of Pseudocyphellaria, when green algal and cyanobacterial states of the same fungus coexist, with one or other state dominant (Armaleo & Clerc 1991; Ryan 2000). These differing photobiont states are termed photosymbiodemes (Renner & Galloway 1982) and appear to be a physiological adaptation of the fungus to differing light levels, enabling a wider exploitation of habitats. Their ecophysiology has been well-studied in forest habitats (Lange et al. 1988; Demmig-Adams et al. 1990; Green & Lange 1991; Lange 1992; Green et al. 1993, 2000, 2002). Nomenclatural discussion of photosymbiodemes is given in Jørgensen (1991, 1996b, 1997b, 1998a), Laundon (1995a, 1996) and Heiđmarsson et al. (1997).
The account of Pseudocyphellaria in the Flora (Galloway 1985a: 420–460) discussed 42 taxa and a later, more detailed monograph recorded 48 taxa (Galloway 1988a). Both of these accounts contain much useful information on the species. Subsequent regional treatments deal with southern South America (Galloway 1992c), the palaeotropics (Galloway 1994b), and Australia (Galloway et al. 2001b). The present account summarises information on 48 species.
