Pyxine cylindrica Kashiw ., Bull. Natl Sci. Mus.

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 : 44

8. Pyxine cylindrica Kashiw., Bull. Natl Sci. Mus. , Tokyo, B, 3 (2): 66 (1977).

Holotype:— PAPUA NEW GUINEA. Morobe District; about 3 km W of Lae, coconut tree plantation, H. Kashiwadani 12382 ( TNS!).

Thallus 2–5 cm wide, adnate, subdichotomously lobate. Lobes radiating, discrete to ± imbricate, plane to slightly convex, 0.3–0.6 mm wide, subrotund to truncate at the apices. Upper surface white to yellowish white or yellowish grey, sparsely pruinose at the lobe tips or epruinose; polysidiangia and soralia absent. Pseudocyphellae distinct, marginal and laminal, irregular or very rarely becoming reticulate. Isidia often along the margins, but also laminal, cylindrical, simple or sparingly branched, 0.3–0.8 mm tall, ca. 0.1 mm wide. Medulla uniformly white. Lower surface black in the centre, paler towards the margin; rhizines ± dense, furcate. Apothecia and pycnidia not seen.

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 (minor), unknown terpenes (minor).

Distribution and habitat:—Rare on bark in dry dipterocarp forest. Also in Australia, South and East Asia and Papua New Guinea.

Notes:—This lichen is characterized by the cylindrical isidia, the white medulla and the presence of atranorin, norstictic acid and testacein. Pyxine keralensis Awasthi is morphologically similar, but it has a yellow-orange medulla and it lacks norstictic acid and testacein.

Material from Thailand examined:— Chiang Mai; Queen Sirikit Botanic Garden , on Syzygium claviflora in an open, dry dipterocarp forest, 870 m, 18°54'33'' N, 98°51'17'' E, 18 March 2008, K . Kalb (hb. Kalb 36807, 36815, 36836)— Chiang Mai; Queen Sirikit Botanic Garden , on Holgarna kurzii in an open, dry dipterocarp forest, 730 m, 18°53'54'' N, 98°51'38'' E, 17 January 1995, K . Boonpragob 3934 ( RAMK 17630 ) .