Heterodermia incana (Stirt.) D.D. Awasthi, Geophytology

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. Heterodermia incana (Stirt.) D.D. Awasthi, Geophytology 3(1): 114 (1973) ( Fig. 12D )

Physcia incana Stirt., Proc. Roy. Philos. Soc. Glasgow 11: 322 (1879); Anaptychia incana (Stirt.) Zahlbr., Cat. Lich. Univ. 7: 727 (1931); Type:— INDIA. Darjeeling; J.A. Thomson 13 (holotype, BM n.v.).

Thallus foliose, forming small rosettes or tufts of suberect to ascending lobes, 3–6 cm wide. Lobes 1–4 mm wide, irregularly to subdichotomously branched, convex, epruinose or slightly pruinose at the tips, not ciliate. Upper surface grayish white, sometimes darkening at the centre, soralia and isidia absent. Marginal rhizines whitish, somewhat darkening at the tips, squarrosely or fruticosely branched. Medulla white. Lower surface ecorticate, arachnoid, uniformly white. Apothecia commonly numerous, pedicellate, subterminal, 1–8 mm wide, margins smooth to lacinulate, sometimes ciliate, disc darkbrown, densely white pruinose. Ascospores Polyblastidia - type, ± constricted at the centre with 2–3 small sporoblastidia 52–56 × 22–27 µm.

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

Distribution and habitat:—This rare species occurs on bark of unidentified trees in lower montane scrub and coniferous forest from 1470 to 1520 m above sea level; also in Taiwan, Java, India and Nepal.

Remarks:— H. incana is similar to H. himalayensis (D.D. Awasthi) D.D. Awasthi , but differs in lacking norstictic acid.

Material from Thailand examined:— Loei: Phuluang Wildlife Sanctuary, area of Kok Nok Kraba and Ban Po Ra Dok , in lower montane scrub, on bark of unidentified tree, 1470 m, 17°16'46'' N, 101°31'08'' E, 29 August 2005, S. Meesim & K. Buaruang, RU-WD155, ( RAMK 21183 ) ; area of Kok Nok Kraba, along trail from Pha Chang Parn to Pha Taloen , in lower montane scrub, on bark of unidentified tree, 1470 m, 17°16'46'' N, 101°31'08'' E, 24 June 2008, S. Meesim & K. Buaruang, RU-MS 76.1, ( RAMK 21081 ) ; ibid, in lower montane scrub, on bark of unidentified tree, 1470 m, 17°16'46'' N, 101°31'08'' E, 13 November 2009, S. Meesim & K. Buaruang, RU-MS0265, ( RAMK 20682 ) ; area of Lan Suriyan , in lower montane scrub, on bark of unidentified tree, 1470 m, 17°16'44'' N, 101°31'07'' E, 25 June 2009, S. Meesim & K. Buaruang, RU-MS29.1, ( RAMK 21022 ) ; forest protection unit, along trail to Tae, area of Pak Dum , in coniferous forest, on bark of unidentified tree, 1520 m, 17°15'07'' N, 101°31'05'' E, 29 August 2005, S. Meesim & K. Buaruang, RU-MSPL 591, ( RAMK 21124 ) .

Figures

FIGURE 12. A. Heterodermia archeri, holotype (scale 5 mm). B. Heterodermia galactophylla, apothecia with ciliate exciple (scale 1 mm). C. Heterodermia hypochraea, holotype (scale 5 mm). D. Heterodermia incana (scale 5 mm). E. Heterodermia podocarpa (scale 1.5 mm). F. Heterodermia stellata, lectotype (scale 1 mm).