Crocynia microphyllina Aptroot
Mycobank MB 517760
Thallus corticolous, crustose, pale greenish white, byssoid, dull, consisting of ca. 0.4–2.0 mm diam crenate thallus areoles of irregular surface and outline on a continuous layer of black arachnoid hypothallus that is underlying the whole thallus, covering areas of up to 10 cm diam, margins delimited by a continuous hypothallus, forming a line of up to 1 mm. Hypothallus filaments 2–3 µm wide, branching mostly perpendicular, surface partly rough from crystals. Phyllidia numerous, ascending, starting at the margins of the areoles, up to 0.3 mm diam and generally ca. 0.2 mm high, scarcely confluent, pale greenish white (not contrasting with the thallus), flattened to globular to irregular, internally formed of branched and gnarled hyphae with copious crystals. Algae chlorococcoid, cells ellipsoid, ca. 5 × 7 µm. Apothecia and pycnidia unknown. Secondary chemistry: protocetraric acid.
Crocynia is a small genus with only two widely accepted species (Cáceres, 2007), which are both often fertile and differ in chemistry, lobe configuration, hypothallus colour, and apothecium characters. This species is the first Crocynia to be described with phyllidia. Although the material is sterile, the byssoid thallus on the arachnoid hypothallus and the presence of chlorococoid algae make a classification in Crocynia possible. The chance that it represents an aberrant morph of one of the known species of Crocynia is low, because the only other species with a dark hypothallus, C. pyxinoides, is restricted to the Neotropics.
The epithet refers to the phyllidiate thallus.
The new species is only known from the type from primary tropical mountain forest dominated by Lithocarpus on a ridge at 1700 m elevation in Papua New Guinea.
Type:—PAPUA NEW GUINEA: Central Province: Owen Stanley Range, Kagi village, along Kokoda Trail towards Gap; 9º08’S, 147º40’E; Oct 1995, Aptroot 39483a (holotype ABL).
Crocynia thallo sterili microphyllino albido, hypothallo extenso nigro, acidum protocetraricum continens.