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Heterodermia albicans
(Pers.) Swinscow & Krog
Thallus foliose, orbicular to irregularly spreading, comparatively small, adnate,
to 4 cm wide. Lobes to 3 mm long, 0.5–1.0 mm wide, to c. 1.5-2.5 mm wide at
the tips, plane to weakly convex, sublinear-elongate, usually richly
dichotomously branched; lobe apices not ascending, eciliate, esorediate. Upper
surface whitish grey to brownish grey, darker at the apices, occasionally
sparsely pruinose; soredia white to bluish grey, forming small continous
marginal soralia towards the thallus centre. Medulla white. Lower surface
corticate, whitish to pale brown, rarely grey. Rhizines marginal and laminal,
simple or irregularly branched, usually short (c. 1 mm long), pale to dark brown
or black. Apothecia very rare, lecanorine. Spores brown, 2-celled. Photobiont:
chlorococcoid. Spot-tests: cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow then red, C–, P+ yellow-orange.
- So far known from a few localities in Sri Lanka, corticolous, in wet upper montane forests above 1200 m
(Kalupahana- Knuckles mountain region).
Heterodermia barbifera
(Nyl.) K.P. Singh
Thallus foliose, corticolous, adnate. Lobes sublinear to strap-shaped, greyish
white to grey above, with branched marginal cilia. Lower surface white, with
rhizines along the lobe margins. Soredia and isidia absent. Apothecia abundant,
lecanorine. Spores brown, 2-celled. Photobiont: chlorococcoid. Spot-tests:
cortex and medulla K+ yellow, C-, KC-, P+ yellow. - Not common on twigs and
branches in both moist and open sunny situations, mostly along forest margins
(Deenston, Corbets Gap, Riverston and Knuckles mountains, Nuwara Eliya).
Heterodermia circinalis
(Zahlbr.) W.A. Weber
Thallus foliose, grey to white (turning brown when dry in exposed situations).
Lobes strap-shaped, thin, with long, black, branched hairs and abundant, black,
simple cilia. Isidia and soredia absent. Apothecia common, lecanorine, the
margin undulate and sometimes star-shaped, the apothecial margin devoid of
cilia. Spores brown, 2-celled. Photobiont: chlorococcoid. Spot-tests: cortex K+
yellow; medulla K+ yellow then red, C-, P-. - Locally abundant on the trunks of
mature trees in shady situations, on roadside soil banks, and moist rocks, mostly
in humid forests and undisturbed areas above 1000 m (Horton Plains, Knuckles
mountain region, Nuwara Eliya and a few places in Kandy.
Heterodermia comosa
(Eschw.) Follmann & Redòn
Thallus foliose, pale grey to whitish above, white below, corticolous, loosely
attached by basal parts. Lobes linear-spathulate to paddle-shaped, sub-erect,
with lateral lobes, bearing abundant white cilia on the upper surface. Soralia
sometimes present on the underside of lobes, apical or subapical. Apothecia rare
(not seen in Sri Lankan material), lecanorine, the margin crenulate. Spores
brown, 2-celled. Photobiont: chlorococcoid. Spot-tests: cortex K+ yellow;
medulla K+ yellow, C-, KC-, P-. - Common but very localised, on twigs in both
humid and exposed situations in wet upper montane forests above 1000 m
(Matale District).
Heterodermia diademata
(Taylor) D.D.Awasthi
Common name:
Cupped fringe lichen
- Thallus foliose, grey to white above,
white and corticated beneath, with marginal rhizines. Lobes adjacent to slightly
disjunct, plane, not ascending, with short lateral lobes. Isidia and soredia absent.
Apothecia numerous, laminal, sessile to substipitate, lecanorine, the disc brown,
the margin crenulate to lobulate. Spores brown, 2-celled. Photobiont:
chlorococcoid. Spot-tests: cortex K+ yellow; medulla K+ yellow, C-, KC-, P+
pale yellow or P-. - Locally abundant on twigs and branches of trees in shaded,
humid situations, more rarely on sheltered rocks, both in man-made and in
natural habitats above 1000 m, mostly growing together with mosses (Knuckles
mountain region, Horton Plains, Kandy, Kegalle, Matale, and Ratnapura District).
