Polyblastidium violostriatum (Elix) Kalb, 2015

Mongkolsuk, Pachara, Meesim, Sanya, Poengsungnoen, Vasun, Buaruang, Kawinnat, Schumm, Felix & Kalb, Klaus, 2015, The lichen family Physciaceae in Thailand-II. Contributions to the genus Heterodermia sensu lato, Phytotaxa 235 (1), pp. 448-450 : 448-450

11. Polyblastidium violostriatum (Elix) Kalb , comb. nov. ( Fig. 11F )

Mycobank MB 813849

Basionym: Heterodermia violostriata Elix, Australas. Lichenol. 69: 16 (2011).

Type:— AUSTRALIA. Queensland: Paluma Ra., Paluma Village , 40 km S of Ingham, 19°01’S, 146°13’E, 830 m, on stem of exotic tree in maintained garden, 29 October 1995, H. Streimann 58057; (holotype, CANB!) .

Thallus foliose, orbicular to irregularly spreading, loosely adnate, 5–12 cm wide. Lobes 1.0– 1.5 mm wide, ca. 2–3 mm wide at the tips, plane to weakly convex or weakly concave, sublinear-elongate, irregularly to digitately branched, radiating; apices not ascending, contiguous to discrete. Upper surface greenish white, whitish gray to creamcolored, epruinose, with marginal to rarely laminal dorsiventral phyllidia, phyllidia minutely dissected, often granular near the tips, or entire phyllidia becoming granular and appearing sorediate. Medulla white. Lower surface ecorticate, arachnoid, violet-gray in the centre, violet-striate towards the apices; yellow pigments absent. Rhizines marginal, at first simple and concolorous with the lower surface, later black and squarrosely branched, 2–4 mm long. Apothecia laminal, adnate to substipitate, 1–4 mm wide; margin phyllidiate, the phyllidia becoming elongate and deeply dissected; disc concave, dark brown to blackish brown, ±grayish pruinose. Ascospores Polyblastidia - type, ellipsoidal, with 0–2 small sporoblastidia, 30–45 × 15–25 µm. Pycnidia common, immersed, then emergent, visible as black dots; conidia bacilliform, 4–5 × 1 µm.

Chemistry: Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow, C–, P+ pale yellow; containing atranorin (major), zeorin (major), 16β-acetoxyhopane-6α,22-diol (major), leucotylin (minor), 6α-acetoxyhopane- 16β,22-diol (major or minor), 6α,16β-diacetoxyhopane- 22-ol (minor), chloroatranorin (minor).

Distribution and habitat:—This very rare species occurs on rocks and bark of trees in a hill evergreen forest in the north of Thailand at 1320 m above sea level; also in Australia; new addition to the Thai lichen biota.

Remarks: — characterized by lobes with an ecorticate, violet-gray to violet lower surface, marginal phyllidia, Polyblastidia - type ascospores and the presence of terpenes in the medulla. Previously misidentified as P. appendiculatum or P. microphyllum ; the former is distinguished from P. violostriatum by the presence of additional norstictic acid, while P. microphyllum has a white lower surface and contains the japonica chemosyndrome of triterpenes.

Material from Thailand examined:— Chiang Mai: Doi Inthanon National Park, area along trail to Siriphum waterfall, in hill evergreen forest, on bark of unidentified tree, 1320 m, 18°32'50'' N, 98°30'56'' E, 9 September 2005, N. Juntawong RU-NJ 277, ( RAMK 21760 ) ;

Figures

FIGURE 11. A. Polyblastidium japonicum (scale 5 mm). B. Polyblastidium microphyllum (scale 5 mm). C. Polyblastidium propaguliferum (scale 5 mm). D. Polyblastidium queenslandicum (scale 5 mm). E. Polyblastidium togashii (scale 5 mm). F. Polyblastidium violostriatum (scale 5 mm).