Porpidia albocaerulescens
≡Lichen albocaerulescens Wulfen in N.J. Jacquin, Collect. Bot. 2: 184 (1788).
≡Huilia albocaerulescens (Wulfen) Hertel, Herzogia 3: 371 (1975).
Descriptions : Flora (1985: 186). See also Rambold (1989: 279–281).
Chemistry : Cortex K−, C−, Pd−; medulla K+ yellow, C−, Pd + orange; containing stictic (major), constictic (minor), norstictic (minor or tr.) acids. A chemodeme with norstictic acid (major) and connorstictic acid (minor) is also recorded (Rambold 1989: 279).
N: Northland (Three Kings Is), Auckland (Rangitoto I.) to Wellington on both east and west coasts (Wellington collections of Charles Knight as "Lecidea littoralis var." [Hertel 1984a: 434]). S: Nelson (Kaihoka Lakes), Marlborough (Kaikoura) to Westland (Bruce Bay). A lowland species, commonly collected from maritime rocks. Earlier records from alpine habitats (Galloway 1985: 186) are in error as pointed out by Hertel (1985b: 327). Australasian collections of this species are discussed in Hertel & Knoph (1984), Hertel (1984b, 1985b, 1987b, 1989b), and Rambold (1989). Known also from Europe, E North America, and SE Asia including Indonesia (Hertel & Knoph 1984: 479, map 1; Hertel 1987b: 331, fig. 3; Nimis & Martellos 2003). It is not known from the Mediterranean area (including Macaronesia), the oceanic parts of Western Europe, Great Britain or Fennoscandia.
Cosmopolitan
Illustrations : Gowan (1989b: 31, fig. 9; 36, fig. 15); Wirth (1995b: 767); Malcolm & Galloway (1997: 53, 106); Dobson (2000: 318 – as P. cinereoatra); Malcolm & Malcolm (2000: 134); Brodo et al. (2001: 584, pl. 705).
Exsiccati : Hertel (1987a: No. 171).
Porpidia albocaerulescens is characterised by: the saxicolous habit; the thick, pale-greyish thallus; sunken apothecia with a densely white-pruinose disc; large ascospores, 18–23 × 7.5–9 μm; and stictic acid in the medulla.
