Polyblastidium hypocaesium (Yasuda) 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

4. Polyblastidium hypocaesium (Yasuda) Kalb , comb. nov. ( Fig. 10E )

Mycobank MB 813842

Basionym: Anaptychia hypocaesia Yasuda, In : Räsänen, J. Jap. Bot. 16: 139 (1940). Type:— JAPAN. Prov. Sagami; Hakone, ad cort. Pini densiflorae, 15 Oct. 1922, Yasuda 674 (H!, holotype; H!, isotype); Heterodermia hypocaesia (Yasuda) D.D. Awasthi, Geophytology 3: 113 (1973).

Thallus foliose, orbicular to irregularly spreading, loosely adnate, to 5 cm wide, but often coalescing to form colonies up to 15 cm wide. Lobes 0.5–1.2 mm wide, to c. 2–3 (–5) mm wide at the tips, plane to weakly convex or weakly concave, sublinear-elongate, dichotomously branched, radiating; apices ascending, usually discrete, ± lobulate along the lobe margins, the lobules ± rounded or sparingly branched, 0.3–0.8 mm wide, 0.5–1.0 mm long.

THE LICHEN FAMILY PHYSCIACEAE IN THAILAND —II

Phytotaxa 235 (1) © 2015 Magnolia Press • 41 Upper surface greenish white, whitish to cream-colored, sorediate; soredia farinose to granular, in labriform to capitate soralia on lateral or terminal lobes, occasionally spreading along the lobe margins. Medulla white. Lower surface ecorticate, ± compact, purple-black in the centre, white, ochraceous or yellow towards the apices. Marginal rhizines common, gray to black, simple or squarrosely branched, 1–3 (–5) mm long. Apothecia very rare, laminal, substipitate, 1–4 mm wide; margin lobulate, the lobules ecorticate, partly yellow on the lower surface, apically sorediate; disc concave, dark brown to blackish brown, sometimes very thinly gray-pruinose. Ascospores Polyblastidia - type, ellipsoidal, with 2 or 3 small sporoblastidia, 35–45 × 16–20 µm. Pycnidia common, initially immersed, then becoming emergent, visible as black dots; conidia bacilliform, 4–5 × 1 µm.

Chemistry: Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow then red, C–, P+ yellow; pigmented medulla K– or K+ brownish green or K+ violet; containing atranorin (major), zeorin (major), japonene (major), salazinic acid (major), ± norstictic acid (minor), hybocarpone (minor), subhypocarpone (trace), 6α-acetoxy-22- hydroxyhopane-25-oic acid (trace), 7-chloroemodin (minor).

Nomenclature notes:— Kurokawa (1962: 57) cited Y. Asahina as collector. But on the labels of the holo- and one isotype, A. Yasuda is mentioned as the collector.

Distribution and habitat:—This species occurs on bark of trees ( Acacia auriculiformis and Alstonia scholaris are reported), dead wood and on rock in lower montane scrub, lower montane forest and hill ever green forest from 975 to 1595 m above sea level; also in Australia, India, Nepal, China, Japan and the Hawaiian Islands.

Remarks: — characterized by lobes with an ecorticate, pigmented lower surface, labriform to capitate soralia, ascospores with sporoblastidia and the presence of medullary salazinic acid, hybocarpone and ± 7-chloroemodin in the lower pigmented medulla. A member of the P. japonicum complex, it is distinguished by the presence of salazinic acid.

Material from Thailand examined:— Phitsanulok: Phu Hin Rong Kla National Park, along trail to Lan Hin Taek area , in lower montane scrub, on bark of Acacia auriculiformis , 975 m, 17°00'27'' N, 100°59'36'' E, 4 February 2003, C . Chansuk RU-CS79, ( RAMK 21450 ); ibid., along trail to Tub Boek area , in lower montane forest, on bark of unidentified tree, 1595 m, 16°55'33'' N, 101°05'58'' E, 1 April 2004, S . Meesim RU-MS39, ( RAMK 21818 ); Kamphaeng Phet: Maewong, along trail Chong Yen , in hill evergreen forest, on bark of unidentified tree, , 1340 m, 16°06'03'' N, 99°06'27'' E, 2 May 2006, S . MeesimRU-MW 7, ( RAMK 21625 ); Nakon Ratchasima: Khao Yai National Park , along main road ca. 100–200 m to view point, in hill evergreen forest, on bark of unidentified tree, 1375 m, 14°21'36'' N, 101°23'47'' E, 23 June 2000, W . Polyiam , RU-20632, ( RAMK 5094 ); ibid., 5 February 2000, W . Polyiam, RU-16732, ( RAMK 7128 ); Phetchaburi: Kaeng Krachan, along trail from Khao Phanoenthung to the guesthouse area, in hill evergreen forest, on bark of unidentified tree, 1207 m, 12°53'07'' N, 99°37'53'' E, 12 February 2006, S . Meesim RU-MS 96, ( RAMK 21622 ); ibid., on Alstonia scholaris, S. Meesim RU-MS 98, ( RAMK 21407 ) .

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).