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Heterodermia hypochraea
(Vain.) Swinscow & Krog
Thallus foliose, the lobes slightly disjunct, convex, ascending, with short lateral
lobes, whitish to greenish grey above, of uneven thickness. Lower surface non
corticate, white, with yellow to ochraceous orange patches which react K+
purple. Isidia and soredia absent. Apothecia apical or subapical, lecanorine,
stipitate, the margin lobulate, with the inner surface of lobules pigmented.
Spores brown, 2-celled. Photobiont: chlorococcoid. Spot-tests: cortex K+
yellow; medulla K- or pigmented part K+ violet, C-, KC-, P + pale yellow or P-.
- Rare and localised, growing on twigs in both humid and dry situations, in wet
upper montane forests above 1000 m (Fishing hut - Peak Wilderness and
Hunuwala Kanda - Matale District).
Heterodermia isidiophora
(Nyl.) D.D. Awasthi
Thallus foliose, corticolous, the lobes slightly disjunct to adjacent, more or less
plane, not ascending, with short lateral lobes. Upper surface greyish white,
densely covered by simple to branched, cylindrical isidia. Lower surface
corticate, white, with rhizines. Apothecia rare (not found in Sri Lankan
material), lecanorine. Spores brown, 2-celled. Photobiont: chlorococcoid. Spot-
tests: cortex and medulla K+ yellow, C-, KC-, P+ yellow or P-. - Common,
mostly on bark, but occasionally also on rocks, in submontane to upper montane
forests above 800 m (Knuckles mountain region, Pattipola, Unulugala Peak,
Fishing Hut, Peak Wilderness, Kabaragala mountain).
Heterodermia japonica
(M. Sato) Swinscow & Krog
Thallus foliose, irregular, dichotomously lobed. Lobes slightly disjunct to
adjacent, more or less plane, sublinear, elongated, radiating, usually wider
towards the apices, with short lateral lobes. Upper surface greenish white,
whitish to cream-coloured, rarely brownish. Lower surface non-corticate, white
to blackish violet, with marginal, simple rhizines. Soralia apical, lip-shaped,
sometimes spreading along the lobe margin. Apothecia rare (not seen in Sri
Lankan material), lecanorine. Spores brown, 2-celled. Photobiont:
chlorococcoid. Spot-tests: cortex and medulla K+ yellow, C-, KC-, P- pale
yellow or P-. - Common on tree trunks or on rocks in open and shady situations
(Knuckles mountains, Matale, Nuwara Eliya, Kandy, Hakgala, Sabaragamuwa
mountain region, Peak Wilderness, Laxapana and Seven Virgin Mountains,
roadside banks along the Haputale-Bandarawela Road).
Heterodermia magellanica
(Zahlbr.) Swinscow & Krog
Thallus foliose, corticolous. Lobes slightly disjunct to adjacent, more or less
plane, not ascending, with short lateral lobes. Upper surface greyish white.
Lower surface non-corticate, white. Isidia and soredia absent. Apothecia laminal
to subapical, sessile to short-stalked, lecanorine, the margin crenulate. Spores
brown, 2-celled. Photobiont: chlorococcoid. Spot-tests: cortex K+ yellow
(turning to red at lobe tips); medulla K+ yellow turning to red, C-, KC-, P+
orange. - Rare and rather localised, on twigs and branches, in both moist and
open, sunny situations, mostly along forest margins (Deenston, Corbet’s Gap,
Riverston and Knuckles mountains, Nuwara Eliya).
