Flora of New Zealand Series

=PHLOEOPANNARIA Zahlbr., 1941

Type : Pannaria rubiginosa (Ach.) Bory [=Lichen rubiginosus Ach.]

Type : Phloeopannaria athrophylla [sic] (Stirt.) Zahlbr.  nomen sed non planta [=Psoroma buchananii]

Description : Thallus squamulose to foliose, heteromerous, dorsiventral, lobate, ±orbicular, ±loosely attached usually without a distinct prothallus. Lobes flat to concave, greyish blue to brownish. Margins ±entire or incised, sometimes producing isidia, or soralia (on lower surface). Upper surface smooth to wrinkled–ridged, scabrid or tomentose or arachnoid, with or without isidia or soredia. Lower surface usually whitish or yellowish to pale-buff, covered in blue-black rhizohyphae. Photobiont cyanobacterial, Nostoc in clusters or chains, present as primary photobiont or restricted to superficial cephalodia; in the latter case, the main photobiont is a green, unicellular alga. Ascomata apothecia, ±frequent, laminal or rarely marginal, with crenulate, well-developed thalline exciple obscuring proper exciple; disc flat becoming convex, epruinose, reddish brown to brown; hymenium near asci I+ blue. Asci apically thickened but without internal amyloid structures. Ascospores ellipsoidal to rarely subglobose, often with a wrinkled and/or apiculate perispore. Conidiomata pycnidia, mostly laminal. Conidia colourless, straight, bacillar.

Pannaria s. str., included in the family Pannariaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005), comprises c. 60 species (Jørgensen 2003c, 2004e; Jørgensen & Sipman 2004) of tropical to warm temperate taxa that are mostly bluish in colour; distinctly foliose; contain pannarin or argopsin (very rarely vicanicin or no substances) or occasionally terpenoids [a yellow species from Heard I. in the southern Indian Ocean, containing anthraquinones (K+ purple), was recently described (Jørgensen 2004a, 2004d)]; have an I+ blue reaction only in the region around the asci; and asci without any amyloid tholus structures. Recently, several large, leafy, subtropical to temperate species formerly placed in Psoroma (e.g. Galloway 1985a: Jørgensen & Galloway 1992), were transferred to Pannaria, reflecting the now expanded limits of Pannaria, which comprise both "green" and cyanobacterial taxa (Jørgensen 2001b; Ekman & Jørgensen 2002; Elvebakk & Galloway 2003; Elvebakk & Bjerke 2005). However, it is recognised that this is really only an interim measure, and that the extensive speciation of "green Pannarias" in the temperate Southern Hemisphere may well represent the emergence of one or more genera independent of Pannaria s. str. for these taxa (A. Elvebakk, pers. comm.). A number of small-squamulose taxa (with possible relationships to different species groups in Psoroma  s. lat.) were segregated from Pannaria and include (1) Fuscopannaria – species with I+ blue hymenium rapidly changing to I+ red-brown and with a distinct amyloid ascus plug, comprising F. crustata, F. decipiens, F. subimmixta (Jørgensen 1994b, 1999a, 2000a, 2000b, 2000c, 2001b, 2002a); (2) Pannaria hookeri although containing pannarin and having asci without any amyloid structures is morphologically, anatomically and phytogeographically so different from Pannaria s. str. that it was considered to belong to a distinct genus along with Pannaria dichroa from Kerguelen (now also known from Campbell I.). These polar–alpine taxa are referred to Pannaria subgen. Cryopannaria P.M.Jørg. (Jørgensen 1994b: 202; 2004a: 237; 2004d) to which Jørgensen (2000c) has recently added a further two new species. However, recent molecular work on the phylogeny of the family Pannariaceae (Ekman & Jørgensen 2002) does not support Cryopannaria as a genus distinct from Pannaria; (3) The Pannaria immixta group with rather leafy, squamulose species, mostly without thallus chemistry and having an I+ blue to dingy blue-black reaction and no amyloid structures in the asci. This appears to be a warm temperate – tropical group of taxa including P. delicata, P. immixta and P. crenulata, which Jørgensen (2004a: 239) has recently formalised as Pannaria subgen. Lepidoleptogium (A.L.Sm.) P.M.Jørg. For the moment they are included here in Pannaria  s. lat. A preliminary account of the genus in New Zealand (Galloway 1985a) takes a wide view of the genus in the sense of Jørgensen (1978), but recent revisions (Jørgensen 1994b, 1999a, 2000c, 2000d, 2001b, 2001c, 2002b; Jørgensen & Arvidsson 2004) discuss the genus in a more restricted sense (see above). Presently, A. Elvebakk (University of Tromsø, Norway) is revising the "green" species of Pannaria in the Southern Hemisphere, and in due course a more natural arrangement of Pannaria s. lat., will hopefully emerge. Chemistry of compounds occurring in green species of Pannaria is critical to the separation of species in this group, and is discussed in Sargent et al. (1976); Elix et al. (1978a, 1982, 1984); Piovano et al. (1985) and Quilhot et al. (1989). Species containing vicanicin (i.e. P. allorhiza, P. athroophylla, P. leproloma, P. mirophyllizans, P. sphinctrina) are always a deep, lettuce-green when wet in the field, in contrast to pannarin-containing taxa (i.e. P. durietzii, P. euphylla, P. pallida, P. patagonica, P. xanthomelana), which are a pale, bluish green when freshly gathered (A. Elvebakk, pers. comm.). All taxa on storage in the dried state revert to a uniform, pale to dark cinnamon-brown colour for vicanicin-containing taxa (Galloway 1985a: 465), and yellow-ochre colour for pannarin-containing species, so accurate observation of thallus colour at the time of collection is an important character in taxonomic separation of species, or species groups.

Jørgensen (2003c: 22; 2004a: 239, 241) recognises three subgenera in Pannaria, the widespread subgen. Pannaria, the bipolar subgen. Cryopannaria, and subgen. Lepidoleptogium (A.L.Sm.) P.M.Jørg., from Australasia (containing the variable P. immixta group), though he recognises that the genus is not uniform, and certainly the variation seen in the different chemical "groups" that exist within Pannaria s. lat. would strongly suggest that the genus could (and perhaps should) be further subdivided.

Twenty-one species are currently accepted in the New Zealand mycobiota. They are best developed, and often highly noticeable, in "oceanic" habitats (moderate shade, warm, and with ±continuous high humidity) in lowland, predominantly coastal areas, being most commonly collected from the northern parts of North I., and the W coast of South I. They are important nitrogen-fixers and undoubtedly major contributors to nitrogen budgets in these biomes. It is recognised that this is still an underestimate of the Pannaria mycobiota of New Zealand, and that more species are known to occur here, with several of these soon to be described. This is part of an extensive study of the "green Pannarias" from the temperate Southern Hemisphere currently in progress, which will be reported upon elsewhere (A. Elvebakk, pers. comm.).