Polyblastidium hypoleucum (Ach.) 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

5. Polyblastidium hypoleucum (Ach.) Kalb , comb. nov. ( Fig. 10F )

Mycobank MB 813843

Basionym: Parmelia speciosa b. hypoleuca Ach., Syn. Lich. : 211 (1814). Type:— U.S.A. Pennsylvania, 29 November 1805, Muhlenberg (lectotype, selected by Moberg & Nash 1999: 5, H) [for collection locality and date, see Lendemer & Hewitt 2002: 187]; Anaptychia hypoleuca (Ach.) A. Massal., Atti Soc. Ital. Sci. Nat. 11:615 (1869); Heterodermia hypoleuca (Ach.) Trevis., Atti Soc. Ital. Sci. Nat. 11: 615 (1869).

Thallus foliose, rarely orbicular, usually irregularly spreading, loosely adnate, to 9 cm wide. Lobes 0.3–1.0 mm wide, to ca. 1.5–2.5 mm wide at the tips, plane to weakly convex or weakly concave, sublinear-elongate, irregularly branched, radiating; apices not ascending, usually discrete, ± lobulate along the lobe margins, the lobules ± rounded, 0.1–0.2 mm wide, eciliate. Upper surface whitish to pale gray, without soralia, isidia or phyllidia. Medulla white. Lower surface ecorticate, ± compact, white to beige in the centre; yellow pigments absent. Marginal rhizines totally black or grayish at the base, simple or squarrosely branched, 1–3 mm long. Apothecia common, laminal, substipitate, 1–7 mm wide; margin crenulate to lobulate, the lobules ecorticate on the lower surface; disc concave, dark brown to brown-black, ± thinly gray pruinose. Ascospores Polyblastidia - type, ellipsoidal, mostly without polyblastidia, albeit in some specimens, almost one third of the spores are with polyblastidia, 23–33 × 12–17 µm. Pycnidia not seen.

42 • Phytotaxa 235 (1) © 2015 Magnolia Press

MONGKOLSUK ET AL.

Chemistry: Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow, C–, P–; containing atranorin (major), zeorin (major), japonene (major).

Nomenclature notes: — Some authors, e.g. Kurokawa (1962: 42) quote Parmelia hypoleuca Muhl., Cat. Pl. Amer. Sept. 1813:105 as basionym. But the genus Parmelia is outlined on p. 102 and no Parmelia hypoleuca is mentioned there.

Distribution and habitat:—Occurs on bark of trees ( Betula alnoides and Acer pseudoplatanus are reported) in lower montane scrub, in lower montane rainforest and in hill evergreen forest in northern Thailand from 1185 to 1340 m above sea level; also recorded from North, Central and South America, Africa and Asia, e.g. Japan and China.

Remarks:— The species is characterized by ± radiating lobe apices, with a whitish lower surface lacking lower cortex, the absence of vegetative propagules, ± small ascospores mostly without sporoblastidia and the lack of depsidones. Polyblastidium magellanicum is very similar, but is readily distinguished by larger ascospores invariably with polyblastidia.

Material from Thailand examined: — Loei: Phuluang Wildlife Sanctuary, trail to Pa Kob Lon Tae forest protection, in lower montane scrub, on bark of unidentified tree, 1245 m, 17°11'32'' N, 101°33'43'' E 17°16'39'' N, 101°31'38'' E, 28 August 2008, S . Meesim & K . Buaruang, RU-MSPL 710, ( RAMK 21156 ); Loei: Phuluang Wildlife Sanctuary, Forest protection unit, area of Lon Tae , in lower montane scrub, on Acer pseudoplatanu , 1260 m, 17°14'18'' N, 101°33'19'' E, 12 November 2009, S . Meesim & K . Buaruang, RU-MSPL 565, , ( RAMK 21122 ); Phitsanulok: Phu Hin Rong Kla National Park, area of Kang Han Nam water fall, in lower montane rain forest, on bark of unidentified tree, 1185 m, 16°59'31'' N, 100°00'44'' E, 4 June 2003, T . Dia, RU-TD 25, ( RAMK 21585 ); Kamphaeng Phet: Maewong, along trail Chong Yen , in hill evergreen forest, on Betula alnoides , 1340 m, 16°06'03'' N, 99°06'27'' E, 2 May 2006, S . Meesim RU-MW 16, ( RAMK 21734 ); Nakon Ratchasima: Khao Yai National Park , along the trail Pha Deaw Dai , in hill evergreen forest, on bark of unidentified tree, 1280 m, 14°22'28'' N, 101°23'04'' E, 10 January 1999, R . Noicharoen RU-16065, ( RAMK 5559 ) .

Figures

FIGURE 10. A. Leucodermia boryi, fertile specimen (scale 5 mm). B. Leucodermia leucomelos, sorediate specimen (scale 5 mm). C. Polyblastidium appendiculatum (scale 5 mm). D. Polyblastidium fragilissimum (scale 5 mm). E. Polyblastidium hypocaesium (scale 5 mm). F. Polyblastidium hypoleucum (scale 5 mm).