Flora of New Zealand Series

≡Lecidea parasema δ [L.] crustulata Ach., Lichenogr. universalis: 176 (1810).

≡Huilia crustulata (Ach.) Hertel, Herzogia 3: 371 (1975).

=Lecidea subglobulata C.Knight, Trans. N. Z. Inst. 8: 314 (1876). Trans. Linn. Soc. ser. 2, Bot. 1: 275 (1877).

Lecidea subglobulata. Holotype: New Zealand. Sine loco [probably Wellington], Charles Knight – WELT. Isotype – BM.

Description : Flora (1985: 186–187). See also Rambold (1989: 285–286) and Galloway & Coppins (1992b: 496).

Chemistry : Cortex K−, C−, Pd−; medulla K± yellow, C−, Pd± orange; lichen substances not detected, or containing stictic acid with traces of cryptostictic, constictic and norstictic acids.

N: South Auckland (Coromandel Peninsula), Wellington (Marton, Maungaroa). S: Nelson (Takaka Hill). Canterbury (Woolshed Hill, Arthur's Pass National Park), Otago (Mt Pisgah, Old Man Ra.), Southland (Catlins, Manapouri, Borland Saddle Fiordland). On stones and pebbles of siliceous rock, often common on roadside pebbles and on rocks in clay banks; associating with Trapelia coarctata and species of Placopsis. A very widespread lichen in temperate habitats of both Northern and Southern Hemispheres (Hertel 1977b; Schwab 1986; Gowan 1989b; Galloway & Coppins 1992b; Gowan & Ahti 1993; Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Scholz 2000; McCarthy 2003c, 2006; Nimis & Martellos 2003; Knoph & Rambold 2004; Santesson et al. 2004; Fryday 2005).

Cosmopolitan

Illustrations : Knight (1876: pl. XI, fig. 4; 1877: pl. XXVII, fig. 4 – as Lecidea subglobulata); Gowan (1989b: 31, fig. 13; 36, fig. 21); Wirth (1995a: 377, pl. 43B; 1995b: 30, 768); Dobson (2000: 319; 2005: 360); Brodo et al. (2001: 585, pl. 706); Fryday (2005: 8, fig. 2A, B, E).

Exsiccati : Hertel (1987a: No. 174).

Porpidia crustulata is characterised by: the saxicolous habit; the pale greenish grey, whitish, olivaceous to somewhat patchily rust-red, thallus, delimited by a fine, black prothallus between contiguous thalli, or thallus becoming eroded and not apparent; abundant, scattered, to crowded (often in concentric rings), sessile, small apothecia, 0.2–1.2 mm diam., the disc black, matt, epruinose, with a thin, persistent, concolorous margin; hymenium thin, 55–90 μm tall; excipular cells, large (5–8 μm diam.) and moderately pigmented; small ascospores, 10–13(–17) × 5–6.5(–9) μm; and a chemistry of stictic acid or without secondary compounds.