Heterodermia comosa (Eschw.) Follmann & Redón
Follman & Redon. Willdenovia 6: 446. 1972
Basionym: Parmelia comosa Eschweiler in Martius. Icon. FI. Crypt. 2: 26. 1828.
Foliose to sub fruticose, forming small rosettes or tufts of ascending lobes, 3–7 cm wide
0.7–5.0 (–8.0) mm wide, sublinear, spathulate or paddle-shaped, convex, rarely branched, ascending or suberect, partially imbricate, with rounded apices when sterile, ciliate; cilia prominent, usually simple, marginal and laminal, whitish, 2–4 mm long
White to grayish white
Sorediate; soredia on the undersides of lobe tips; marginal rhizines whitish, mostly simple, sometimes furcate or irregularly ramified
Lower Side :
Ecorticate, arachnoid, uniformly white, apically sorediate when sterile, erhizinate
Subterminal to terminal on ascending lobes, substipitate, 1–5(–10) mm wide; margin crenate or lobulate, ciliate; disc dark brown, densely whitish gray pruinose
Polyblastidia-type, narrowly ellipsoid to fusiform, with 2–3 sporoblastidia, 31–35 × 13–16 μm. Pycnidia not seen.
Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow, C–, P–; pigmented lower surface K+ violet; containing atranorin (major), zeorin (major), 6α-acetoxyhopane-16β,22-diol (minor), ± 7-chloroemodin (minor to trace)