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colourless, 1-celled. Photobiont: chlorococcoid. Spot-tests: cortex K+ yellow
(atranorin). Medulla K+ yellow then dark red, C-, KC-, P+ orange (salazinic
acid). - A pantropical corticolous species, reported from South America,
Indonesia, India, Africa, Australia, Macquarie Island, the Pacific and Papua
New Guinea.
Hypotrachyna crenata
(Kurok.) Hale
Thallus foliose, 3-6 cm wide, loosely adnate with subirregular to subimbricate,
1.5-5 mm wide lobes with subrotund to subtruncate apices; isidia moderate to
dense, cylindrical, simple or branched. Lower surface black in centre with pale
brown papillate marginal zone; rhizines sparse to moderately branched.
Apothecia very rare, lecanorine. Spores colourless, 1-celled. Photobiont:
chlorococcoid. Spot-tests: cortex K+ yellow (atranorin ± trace of usnic acid).
Medulla K+ yellow, C-, KC-, P+ pale orange, with stictic acid (major),
norstictic acid (minor), menegazziaic acid (minor) and related compounds
(traces). - A corticolous species of humid, mossy forests, also reported from the
eastern Pacific, India, Indonesia, Taiwan, and Thailand.
Hypotrachyna exsecta
(Taylor) Hale
Thallus foliose, 5-13 cm wide; lobes 1-3 mm wide, often crowded, with
subterminal or occasionally laminal pustules which are sometimes tall and open,
mostly erumpent, eventually eroding and becoming coarsely granular-sorediate.
Lower surface black, with densely branched rhizines that frequently project
beyond lobe margins. Apothecia very rare, lecanorine. Spores colourless, 1-
celled. Photobiont: chlorococcoid. Spot-tests: cortex K+ yellow (atranorin).
Medulla K-, C+ orange, KC+ deep orange, P- (barbatic and 4–O–
demethylbarbatic acids). - A corticolous species of humid, mossy forests, also
reported from Australia, SE Asia, E Asia, the Pacific, and Papua New Guinea.
Hypotrachyna imbricatula
(Zahlbr.) Hale
Thallus foliose, adnate, 2-12 cm wide, subdichotomously to subirregularly
branched; lobes 1.5-4 mm wide with truncate apices and margins often
irregularly incised. Upper surface with isidia, rarely becoming lobulate or
procumbent. Lower surface black; rhizines richly branched and often projecting
beyond lobe margins. Apothecia very rare, lecanorine. Spores colourless, 1-
celled. Photobiont: chlorococcoid. Photobiont: chlorococcoid. Spot-tests: cortex
K+ yellow (atranorin). Medulla K-, C-, KC+ orange, P-, with barbatic acid
(major), obtusatic acid (major/minor), 4–O–demethylbarbatic acid (minor),
norobtusatic acid. - A widely distributed, mainly corticolous, subtropical–
tropical species.
Hypotrachyna immaculata
(Kurok.) Hale
Thallus foliose, loosely to tightly adnate, up to 5(-7) cm wide, with contiguous, sublinear, 1.5-3 mm wide lobes with
incised apices. Upper surface whitish grey with large (1-2 mm wide), capitate soralia. Medulla mostly white, orange–
brown below soralia. Lower surface with dense, dichotomous rhizines. Apothecia lecanorine. Spores colourless, 1-
celled. Photobiont: chlorococcoid. Spot-tests: cortex K+ yellow (atranorin). Medulla K- or K+ pale reddish, C-, KC+
