Heterodermia himalayana Y. Joshi, K. Chandra & M. Tripathi, 2014

Joshi, Yogesh, Chandra, Krishna & Tripathi, Manish, 2014, A new species of Heterodermia (Ascomycota, Physciaceae) from India, along with a new record and range extension of lichenized fungi in India, Phytotaxa 170 (1), pp. 49-52 : 50-51

Heterodermia himalayana Y. Joshi, K. Chandra & M. Tripathi , sp. nov. ( Fig. 1 a&b )

MycoBank no.: MB 808586

Differs from Heterodermia koyana in having intermittently yellow medulla, pruinose apothecial disc, and smaller ascospores [15–20(–28) × 08–12(–18) µm].

Type:— INDIA. Uttarakhand: Pithoragarh district, Ek Hathiya temple, 29˚49’N, 80˚09’E, alt. 1081 m, on rock, 15 December 2013, Krishna Chandra 259 (holotype ALM, isotype LWG) .

Thallus foliose, orbicular to irregularly spreading, loosely adnate, 5–10 cm wide. Lobes 0.7–2.0 mm wide, plane to weakly convex or weakly concave, sublinear-elongate, dichotomously to sub digitately branched; apices not ascending, ±discrete to contiguous at the periphery, with short lateral lobes, eciliate. Upper surface ash gray, ±pruinose, with marginal phyllidia or dorsiventral lobules; lobules usually minutely dissected and appearing sorediate. Medulla white (K+ yellow) to intermittently yellow (K+ purple). Lower surface corticate, white to pale brown. Rhizines numerous, mainly marginal, concolorous with the thallus or darkening and forming a dense black marginal mat, irregularly branched. Apothecia numerous, scattered to aggregated (2-5), laminal, sessile to substipitate, 1–5 mm wide; disc concave, brown to brown-black, epruinose to ±pruinose. Ascospores Pachysporia - type, lacking sporoblastidia, ellipsoidal, 15–20(–28) × 08–12(–18) µm. Pycnidia initially immersed, then becoming emergent, visible as black dots; conidia bacilliform, 4–5 × 1 μm.

Chemistry: —Cortex K+ yellow, C–, KC–, P–; medulla K+ yellow to purple, C–, P–. TLC: atranorin, zeorin, 16ssacetoxyhopane-6α, 22-diol, 6α-acetoxyhopane16ss,22-diol, dissectic acid and 7-chloroemodin.

Etymology: —The species is named after the region of occurrence, the Himalaya.

Distribution and Ecology:— The species is so far known from the type locality only, where it occurs on rocks nearby Ek Hathiya temple at an elevation of about 1000 m in a transition zone between mixed forest and crop land. Associated species include Dermatocarpon vellereum Zschacke (1934: 638) , Heterodermia pseudospeciosa (Kurok.) W.L. Culb. (1967: 484) , H. japonica (M. Satô) Swinscow & Krog (1976: 122) , Parmotrema praesorediosum (Nyl.) Hale (1974: 338) , Phaeophyscia hispidula (Ach.) Moberg (1978: 305) , Parmotrema reticulatum (Taylor) Choisy (1952: 175) and Pyxine cocoes (Sw.) Nyl. (1857: 108) .

Remarks: —The new species is characterized by an ash gray thallus with minutely dissected phyllidia or dorsiventral lobules, corticate lower surface, white to intermittently yellow medulla and sessile to substipitate apothecia with Pachysporia type ascospores. Heterodermia koyana Elix (2010: 61) , previously classified as H. dissecta var. koyana (Kurok.) Wei (1973: 113) is similar in having phyllidiate isidia/dorsiventral lobules, and similar ascospores and medullary chemistry. However, it differs in having larger spores [28–32 × 12–16], a white medulla, and epruinose apothecial discs.

Other species with intermittently yellow medulla include H. albidiflava (Kurok.) D.D. Awasthi (1973: 113) , H. corcovadoensis (Kurok.) Elix (2011a: 19) , H. firmula (Nyl.) Trevis. (1868: 615) , H. lutescens (Kurok.) Follmann (1974: 3) and H. obscurata (Nyl.) Trevis. (1869: 114) , but the new species differs in several respects. Heterodermia albidiflava and H. firmula lack dissectic acid; H. corcovadoensis and H. obscurata have ecorticated lower surfaces and Polyblastidia- type ascospores and also lack dissectic acid.

Species such as H. appendiculata (Kurok.) Swinscow & Krog (1976: 114) , H. coralloidea Elix (2011b: 12) , H. dissecta (Kurok.) D.D. Awasthi (1973: 113) , H. fragilissima (Kurok.) Wei & Jiang (1986: 111) , H. koyana (Kurok.) Elix (2010: 61) , H. lepidota Swinscow & Krog (1976: 122) , H. tasmanica Elix (2011b: 15) , H. verdonii Elix (2011a: 18) and H. violostriata Elix (2011b: 16) resemble the new taxon in having phyllidiate thalli, but differ in several characters. For example, H. appendiculata , H. fragilissima , H. tasmanica and H. violostriata have an ecorticate lower side, a distinct white medulla, Polyblastidia type ascospores and lack dissectic acid; H. dissecta and H. koyana have distinct white medullae; H. coralloidea and H. lepidota have distinct white medulla and lack dissectic acid; H. tasmanica , a sterile species, differs in having ecorticate lower side and white medulla.

Figures

FIGURE 1. Heterodermia himalayana (holotype) a. Thallus with phyllidia/dorsiventral lobules (Scale = 5 mm); b. Inset image showing yellow medulla (Scale = 2 mm).