55
Photobiont: cyanobacterial (
Scytonema
). Spot-tests: cortex and medulla K-,C-,
KC-, P-. - On mature trunks of trees in shady interiors and rarely on mossy
rocks, mostly in humid forests above 1200 m, restricted to the Central
Highlands.
Coccocarpia stellata
Tuck.
Thallus foliose, irregularly orbicular, loosely attached, the lobes disjunct to
adjacent, linear-cuneate to flabellate, 0.2-1 mm wide, bluish grey, with
occasional concentric or transverse ridges. Rhizines sparse, white to bluish
black, projecting beyond the apices of lobes. Isidia and soredia absent.
Apothecia abundant, brownish red, orbicular, at least some of them with
conspicuous radiating excipular hairs, mainly marginal. Photobiont:
cyanobacterial (
Scytonema
). Spot-tests: K-,C-, KC-, P-. - On mature leaves and
thin branches in more or less well-lit situations, mostly in humid, high elevation
forests above 1600 m, restricted to Horton Plains and Hakgala strict nature
reserve.
Coenogonium linkii
Ehrenb.
Thallus byssoid, composed of very thin filaments forming a network on the
surface of the photobiont, soft, with a woolly appearance, forming light green to
white tufts which are slightly lifted from the bark, without soredia or isidia.
Apothecia common, flat, thin, yellowish orange, without a thalline margin.
Spores colourless, 2-celled. Photobiont:
Trentepohlia
. Spot-tests: K-,C-, KC-, P-
. - Very common on mature tree trunks in very humid, shaded situations and on
moist rocks, mostly in humid mid-elevation to high-elevation forests above
1000 m (Central Highlands, and along rocky stream margins in submontane and
montane forests).
Coenogonium luteum
(Dicks.) Kalb & Lücking
Thallus crustose, thin, spreading, up to 8 cm in diam., varnish-like, continuous
or cracked-areolate or lacking surface, pale yellowish green to dark olive-green
in shaded situations. Apothecia common and conspicuous, sessile, round,
without a thalline margin, ca. 0.42 mm wide, usually scattered, clearly
constricted below margin, pale flesh-coloured, the proper margin prominent,
entire or flexuous, occasionally with a faint pale pruina in older apothecia. Disc
orange-yellow, red-orange to yellow-red, shallowly concave, then convex,
epruinose. Spores colourless, 3-septate, fusiform to fusiform-ellipsoid.
Photobiont:
Trentepohlia
. Spot-tests: K-,C-, KC-, P-. - Locally very common on
mature tree trunks in very humid upper montane forests above 1200 m
(Dotalugala Mnt. of Knuckles mountain region and Hakgala Reserve).
Collema coilocarpum
(Müll. Arg.) Zahlbr.
Thallus foliose, mainly corticolous, homoiomerous, pulpy and swollen when wet, irregularly spreading, mostly dark
olive green but often partly pale and membranous, becoming purplish grey blue when dry, rugose and fenestrate, the
margins strongly ascending. Isidia absent, but often the thallus develops erect, thickened lobules or cylindrical
