Xanthoparmelia volcanicola Jayalal, Divakar & Hur, 2014

Jayalal, Udeni, Divakar, Pradeep K., Joshi, Santosh, Oh, Soon Ok & Hur, Jae-Seoun, 2014, Overview of Xanthoparmelia taxa from South Korea including the description of two new species (Parmeliaceae, Ascomycota), Phytotaxa 181 (2), pp. 96-109 : 101-104

Xanthoparmelia volcanicola Jayalal, Divakar & Hur , sp. nov. ( Fig. 3 )

MycoBank # MB 808645

Thallus adnate to loosely adnate thallus, upper surface yellowish green, lower surface brown to red brown, medulla deep purple, isidia subglobose and containing usnic acid, norstictic acid and an unknown compound.

Type: — SOUTH KOREA. Jeju Island , 1 m alt, on volcanic rock at the seashore, 33°22’N, 126°52’E, 17. 10. 2006, J. S. Hur –061014 (holotype: KoLRI 005398!) .

Thallus foliose, adnate to loosely adnate, saxicolous, 3–5 cm wide; lobes sublinear to subirregular, 0.2–2.5 mm wide, 130–230 μm thick, short flat to somewhat convex or concave, contiguous to sparingly imbricate; upper surface dull yellowish green, continuous, emaculate, shiny, subrugulose, smooth, flat, dark brown and shiny at the lobe apices, becoming dull and cracked in the older parts of the thallus, rather fragile and breaking open to reveal the purple medulla, isidiate; isidia moderately dense, subglobose to cylindrical, simple to branched, 0.06–0.18 mm diameter, 0.2–0.6 mm high, tips syncorticate, medulla whitish to deep purple, young lobes with whitish medulla, older lobes with deep purple medulla, 80–170 μm thick, lower cortex thick, 12–15 μm thick, lower surface plane, pale brown to reddish brown, moderately rhizinate. Rhizines simple to sparsely furcate, concolorous to blackish, 0.2–0.6 mm long. Apothecia and pycnidia lacking.

Chemistry: —Thallus K–, C–, KC+ (pale yellow), P–; Medulla K+ (yellow-orange), C–, KC–, P+ (pale orange). HPLC /TLC: usnic acid (major), fumarprotocetraric acid (minor), succinprotocetraric acid (minor), norstictic acid (major), unknown compound (minor), unknown anthraquinone pigment and unknown compounds of retention times in minutes at 2.315, 4.589, 6.359, 7.243 and 17.194.

Etymology: —The specific epithet volcanicola is derived from the volcanic rock on which this species was collected.

Habitat and distribution: —Two specimens were found; both from volcanic rock surfaces at low elevation close to the seashore.

Remarks:—This is the first Xanthoparmelia species found in East Asia to have a red-pigmented medulla. It is further characterized by the yellowish green upper surface, the adnate to loosely adnate thallus, brown to red brown lower surface, the presence of deep purple medulla (only in older portions of the thallus) and subglobose isidia and by the presence of norstictic acid as major component together with cortical usnic acid and an unknown compound. In the phylogenetic tree ( Fig. 1 ), the new taxon clusters with two samples of X. subramigera and one of X. conspersa , however, the relationship lacks support. The latter two species have a white medulla and contain succinprotocetraric and fumarprotoceraric, and stictic acids, respectively. Since this relationship lacks statistical support, the phylogenetic position of this new taxon remains unresolved in clade A.

According to Hale (1990), 47 species of Xanthoparmelia were found to contain medullary pigments, the most frequent being the orange–red skyrin and dull rusty reddish schenckiana pigments. Most of the species with pigmented medulla are confined to South Africa, with a limited number of additional species reported from Australia ( Elix 1994) and New Zealand ( Galloway 2007).

This new species resembles Xanthoparmelia rubropustulata Hale (1987: 264) , both having adnate to loosely adnate thallus, dull yellowish green thallus, sublinear to subirregular lobes, brown lower surface, the presence of deep purple medulla and the presence of isidia. X. rubropustulata is distinguished by narrower lobes (1–1.5 mm wide), globose pustulate isidia, uniformly deep purple medulla and the presence of salazinic acid. Xanthoparmelia endomiltoides (Nyl.) Hale (1974: 487) is another species with a red pigmented medulla but differs in the absence of isidia and the presence of the salazinic acid chemosyndrome.

Figures

FIGURE 1. The 50% majority-rule consensus tree of the molecular phylogenetic relationships of South Korean Xanthoparmelia species, based on 18000 trees from a B/MCMC tree-sampling procedure of ITS ribosomal DNA dataset of the “focal-group”.Posterior probabilities ≥ 0.50 are given above the branches, and values below the branches are ML bootstrap values ≥ 50%. Branches that received strong support in any of the two analyses (≥ 70% in RaxML and ≥ 0.95 in B/MCMC) are in boldface.

FIGURE 3. Xanthoparmelia volcanicola. A. Habit; B. transverse section through thallus (T. S) (uc—upper cortex, al—algal layer, m— medulla, lc—lower cortex); C. part of thallus showing deep purple medulla; D. subglobose to cylindrical isidia on thallus; Scale Bars A = 1 cm, B = 20 μm, C, D = 0.5 mm.