top of page

Polyblastidium hypocaesium (Yasuda ex Räsänen) Kalb

Family :


Mongkolsuk, Meesim, Poengsungnoen, Buaruang, Schumm & Kalb, Phytotaxa 235(1): 41 (2015)

Previously : Heterodermia hypocaesia (Yasuda) D.D.Awasthi

D. Awasthi, Geophytology 3: 113.1973; Singh & Sinha 1994: 419.  

Basionym: Anaptychia hypocaesia Yasuda in Rasanen, J. Jap. Bot. 16: 139. 1940

ID :


Thallus :

Foliose, orbicular to irregularly spreading, loosely adnate, to 5 cm wide, but often coalescing to form colonies up to 15 cm wide

Lobes :

0.5–1.2 mm wide, to c. 2–3 (–5) mm wide at the tips, plane to weakly convex or weakly concave, sublinear-elongate, dichotomously branched, radiating; apices ascending, usually discrete, ± lobulate along the lobe margins, the lobules ± rounded or sparingly branched, 0.3–0.8 mm wide, 0.5–1.0 mm long.

Upper Side:

Greenish white, whitish to cream-colored

Isidia :

Sorediate; soredia farinose to granular, in labriform to capitate soralia on lateral or terminal lobes, occasionally spreading along the lobe margins

Lower Side :

Ecorticate, ± compact, purple-black in the centre, white, ochraceous or yellow towards the apices. Marginal rhizines common, gray to black, simple or squarrosely branched, 1–3 (–5) mm long

Medulla :


Very rare, laminal, sub stipitate, 1–4 mm wide; margin lobulate, the lobules ecorticate, partly yellow on the lower surface, apically sorediate; disc concave, dark brown to blackish brown, sometimes very thinly gray-pruinose

Apothecia :

Polyblastidia-type, ellipsoidal, with 2 or 3 small sporoblastidia, 35–45 × 16–20 μm. Pycnidia common, initially immersed, then becoming emergent, visible as black dots; conidia bacilliform, 4–5 × 1 μm

Ascospores :

Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow then red, C–, P+ yellow; pigmented medulla K– or K+ brownish green or K+ violet; containing atranorin (major), zeorin (major), japonene (major), salazinic acid (major), ± norstictic acid (minor), hybocarpone (minor), subhypocarpone (trace), 6α-acetoxy-22- hydroxyhopane-25-oic acid (trace), 7-chloroemodin (minor)

Chemistry :

bottom of page