Pyxine profallax Kalb, Bibl. Lichenol.

Mongkolsuk, Pachara, Meesim, Sanya, Poengsungnoen, Vasun & Kalb, Klaus, 2012, The lichen family Physciaceae in Thailand-I. The genus Pyxine, Phytotaxa 59 (1), pp. 32-54 : 48-49

14. Pyxine profallax Kalb, Bibl. Lichenol. 99: 243 (2009).

Holotype: PAPUA NEW GUINEA. Central District ; around Woitape, ca. 1600 m, 19 October 1975, Kurokawa 9309 ( TNS!).

Thallus corticolous, 3–5 cm wide, adnate. Lobes radiating, discrete to ± imbricate, plane to slightly concave, 0.8–1.0 mm wide, subrotund to truncate at the apices. Upper surface whitish to grey or brownish grey, sparsely pruinose at the lobe tips or epruinose; polysidiangia, isidia and soralia absent. Pseudocyphellae distinct, marginal and laminal, irregular, becoming reticulate on the upper surface. Medulla uniformly white. Lower surface black in the centre, paler towards the margin; rhizines ± dense, furcate. Apothecia common, obscurascens - type, 0.5–1.0 mm wide; disc black, not pruinose. Internal stipe distinct, white, K-, P-. Ascospores 16–22 × 6–8 μm. Pycnidia laminal, immersed to slightly sessile, black; conidia bacilliform, 3–4 × 1 µm.

Chemistry: Cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K+ yellow → red, C-, P+ orange; containing atranorin (minor), chloroatranorin (minor), norstictic acid (major), testacein (submajor), unknown terpenes showing the same array as P. fallax (minor).

Distribution and habitat:—A very rare species, corticolous in a lower montane scrub. Also in Papua New Guinea (holotype).

Notes:— Pyxine profallax is characterized by the adnate thallus, the absence of soredia, isidia and polysidiangia, the uniformly white medulla with norstictic acid, cortical atranorin, and obscurascens - type apothecia. P. philippina and P. schmidtii are very similar as both lack vegetative propagules and contain additional testacein, but the latter lacks norstictic acid and the former contains a different array of terpenes.

Material from Thailand examined:— Loei; Phu Luang Wildlife Sanctuary, Lan Suriyan , on bark in a lower montane scrub, 1473 m, 17°16'44'' N, 31°07'02'' E, 25 June 2008, S. Meesim 29 ( RAMK 17620 ) .