Pyxine australiensis Kalb, 1994

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 : 36-37

2. Pyxine australiensis Kalb , Herzogia 10: 61 (1994).

Type:— AUSTRALIA. Queensland: Sunshine Coast; near Minyama , ca. 100 km N of Brisbane , on trees along the shore, 26°41' S, 153°08' E, 19 August 1988, K. & A. Kalb s.n.; (holotype:— CANB!; isotype:—hb. Kalb 19767!) .

Thallus corticolous, rarely saxicolous, 5–10 cm wide, adnate to tightly adnate. Lobes radiating, discrete to ± contiguous, plane to convex, but often slightly concave towards the tips, 0.5–0.8 mm wide, subrotund at the apices. Upper surface white to greenish grey or yellow-grey, sparsely pruinose at the lobe tips or epruinose; polysidiangia, isidia and soralia absent. Pseudocyphellae distinct, marginal and laminal, subreticulate. Medulla uniformly pale yellow to lemon yellow. Lower surface black in the centre, paler towards the margin; rhizines ± dense, furcate. Apothecia common, obscurascens - type (erroneously reported as cocoës - type in the protologue), 0.5–1.5 mm wide; disc epruinose. Internal stipe distinct, white, K-, P-. Ascospores 16–22 × 6–7.5 µm. Pycnidia not seen.

Chemistry: Cortex K-, UV + yellow; medulla K- or K + pale red, C-, KC-, P- or P + orange; containing lichexanthone (major), terpenes (major or minor), unknown pigment (minor or trace).

Distribution and habitat:—Very rare on bark, (rarely on rocks in Australia), in a mixed deciduous forest. Also in Australia and South America.

Notes:—This species is characterized by the cortical lichexanthone, the absence of vegetative propagules, the uniformly yellow medulla and apothecia of the obscurascens - type with a white internal stipe. Pyxine berteriana is very similar, but has somewhat broader lobes (0.5–1.5 mm) and a medulla that is only yellow in part. Furthermore the apothecia of P. berteriana are of cocoës - type and the two species contain very different arrays of terpenes ( Kalb, 1994).

Material from Thailand examined:— Nakhon Ratchasima; Khao Yai National Park , on the bark of an unidentified tree in mixed deciduous forest, 1100 m, 14°32' N, 101°40' E, 8 April 1999, P . Mongkolsuk 13816 ( RAMK) .