Pyxine asiatica Vain.

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 : 35

1. Pyxine asiatica Vain. , Hedwigia 46: 171 (1907).

Type:— THAILAND. Trat; In insula Koh Chang prope Lem Dan , ad corticem Arecae catechu, J . Schmidt 10 (lectotype, selected by Rogers 1986: 149.— TUR-VAIN. 8697!) .

Thallus corticolous, 2–6 cm wide, adnate to tightly adnate. Lobes radiating, discrete to ± contiguous in center, apices discrete, plane to distinctly concave, in older thalli becoming slightly convex in the centre, 0.5–1.2 mm wide, subrotund to truncate at the apices. Upper surface white to whitish grey or greenish grey, not pruinose or seldom with a punctiform pruina at the lobe tips. Polysidiangia and isidia absent. Soralia capitate, laminal with white farinose to minutely granular soredia. Pseudocyphellae distinct, usually restricted to the margins but also a few laminal, becoming subreticulate with age. Medulla uniformly white. Lower surface black in the centre, paler towards the margin; rhizines ± dense, furcate. Apothecia not common, obscurascens - type, 0.7–1.5 mm wide; disc epruinose. Internal stipe distinct, white, K-, P-. Ascospores 15–19 × 5–6 µm. Pycnidia not seen.

Chemistry: Cortex K + yellow, UV-; medulla K + yellowish, C-, KC-, P + orange to orange-red; containing atranorin (major), testacein (major), terpenes (major or minor).

Distribution and habitat:—Very rare on bark, in a dry evergreen forest. Also in India and Japan.

Notes:—This species is characterized by the cortical atranorin and medullary testacein, the presence of laminal soralia, the uniformly white medulla, apothecia of the obscurascens - type with a white internal stipe. Pyxine fallax (Zahlbr.) Kalb and P. copelandii Vain. are very similar, but both are readily separated by the presence of norstictic acid, and the three species contain very different arrays of terpenes.

Material from Thailand examined:— Nakhon Ratchasima; Khao Yai National Park , on the bark of an unidentified tree in dry evergreen forest, 780 m, 14°25' N, 101°42' E, 9 January 1999, P . Mongkolsuk 12659 ( RAMK) .