Leucodermia leucomelos (L.) Kalb

Family :

Physciaceae

Mongkolsuk, Meesim, Poengsungnoen, Buaruang, Schumm & Kalb, Phytotaxa 235(1): 35 (2015) Basionym: Lichen leucomelos Linnaeus Sp. PI. ed. 2, 2: 1613. 1763.

ID :

BU/BRL/2022/022

Thallus :

Foliose to sub fruticose, often in loose rosettes or forming tangled mats, loosely adnate or, in part, unattached, 5–15 cm wide

Lobes :

0.5–4.0 mm wide, separate, ±plane, linear-elongate, ribbon-like, tangled, dichotomously branched, often ascending at the apices or, occasionally, the apices reflexed, with conspicuous long, gray to black simple or squarrosely branched marginal rhizines, 5–15 mm long

Upper Side:

Ivory to gray-white, smooth, epruinose

Isidia :

Lower Side :

Predominantly ecorticate, but with thickened corticated margins, canaliculate, arachnoid or powdery and then becoming sorediate, often with subapical soralia, white throughout or partially pinkish brown or, rarely, purple; yellow pigments absent

Medulla :

White

Rare, subapical to apical, sub stipitate to distinctly stipitate, 2–5 mm wide; margin crenulate to lobulate, the lobules triangular, to 3 mm long, often with sparse short black cilia along the margins of the lobules; disc concave, dark brown to black, ± white-pruinose

Apothecia :

Polyblastidia-type, ellipsoidal, with numerous small or large sporoblastidia, 31–50 × 15–24 μm. Pycnidia rare, immersed, visible as black dots; conidia

Ascospores :

Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow then red, C–, P+ dark yellow; containing atranorin (major), zeorin (major), japonene (minor or trace), salazinic acid (minor), consalazinic acid (trace)

Chemistry :