Heterodermia diademata (Taylor) D.D.Awasthi

Family :

Physciaceae

D. Awasthi, Geophytology 3: 133. 1973; Singh & Sinha 1994:412.  

Basionym: Parmelia diadernata Taylor, London J. Bot. 6: 165. 1847.

ID :

BU/BRL/2022/010

Thallus :

Foliose, orbicular to irregularly spreading, adnate to loosely adnate, to 15 cm wide

Lobes :

0.5–2.5 mm wide, plane to weakly convex or weakly concave, sublinear-elongate, sympodial to irregularly branched, contiguous or discrete at the periphery, radiating; apices not ascending, with short lateral lobes, eciliate

Upper Side:

Greenish white, whitish or gray, pruinose or not, rarely with marginal lobules

Isidia :

Isidia, Phyllidia and Soralia absent

Lower Side :

Corticate, whitish to pale brown to dirty brown towards the center, smooth to strongly corrugated. Lower surface rhizines and marginal rhizines comparatively sparse, the latter sometimes projecting from the thallus, concolorous with the thallus or darkening at the apices, simple or irregularly or squarrosely branched

Medulla :

White 

Laminal, sessile to sub stipitate, 1.5–5.5 mm wide; margin entire, crenulate to lobulate; disc concave, brown to brown-black, epruinose

Apothecia :

Pachysporaria-type, ellipsoidal, 25−40 × 10−17 μm. Pycnidia common, immersed or slightly protruding; conidia bacilliform, 3–4 × 1 μm

Ascospores :

Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow, C–, P–; containing atranorin (major), zeorin (major), 16β-acetoxyhopane-6α,22-diol (major), leucotylin (minor), 6α-acetoxyhopane-16β,22-diol (minor), 6α,16β-diacetoxyhopane-22-ol (minor or trace)

Chemistry :