Fascinating Lichens of Sri Lanka

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Heterodermia propagulifera
Heterodermia pseudospeciosa
SL
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Fo
Physciaceae
Description Foliose. The thallus is adnate and ascends towards the margin. The
upper surface is grey green. The lower surface has red spots. Cilia are black, dull,
marginal and simple. Rhizines are black and simple. Soredia are mainly found on
the secondary lobes. Apothecia are not seen in Sri Lankan material.
Status This rare species was only found once on a tree in a shaded interior.
Habitat Found only in montane forests above 1400m. Grows together with
mosses.
Locations Horton Plains, Kalupahana in the Knuckles mountain region (only
photographs were taken).
Description Foliose. The thallus is small, usually less than 4 cm in diameter,
loosely attached and densely dichotomously branched. Lobes are long and
narrow, repeatedly branched, weakly convex and widening. The upper surface
is greyish white to grey to brownish grey, darker at lobe tips, sometimes weakly
pruinose and sorediate. Soredia are white to bluish grey, mainly arising from small
lateral knob-like structures. The lower surface has a cortex and rhizines. Rhizines
are weakly developed, usually short and pale to dark brown or black. Apothecia
are rare, margins are sorediate with a brown to blackish brown disc.
Status This rare species is a new record for Sri Lanka and has only been spotted
a few times. It is mostly a Northern Hemisphere species, which is scattered in
various localities across all the continents. This species is characterized by the
narrow, convex, long lobes and the soralia that mainly arise from the marginal
knob-like structures forming small, semi-capitate soralia.
Physciaceae
Habitat On rocks, and more rarely on trees in open but humid situations.
Locations Nawalapitiya and Laxapana areas.
92 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 93