in A. Frisch, G. Thor and J. A. Elix, The Bryologist113(1): 145 (2010)
Thallus corticolous, delimited by a distinct byssoid prothallus of white, radiating hyphae typically at least in part with a rust-red pigment; thallus surface grayish white, with storage becoming ±beige, ecorticate, cottony, in parts almost granular, in the center densely covered by slightly darker, compact pseudisidia that appear as if sprinkled with rust-red crystals; pseudisidia dimorphic, either swollen, globular containing one central pycnidium or, with age, elongate cylindrical to ±vermiform; medulla white, filled with brownish granules and sparse calcium oxalate crystals (insoluble in KOH, forming colorless, needle-shaped crystals in 25% H2SO4); asci not observed; pycnidia embedded within pseudisidia, opening with an aeruginose ostiole, pigmentation occasionally extending along the pycnidial wall, conidiophores simple, with oblong to bacilliform conidia, 3-4 x 1-1.5 μm.
Spot tests and chemistry: P+ bright yellow; , K- (greenish white thallus areas), K+ purple (bright red crystal of the pseudoisidia and rust reddish prothalline hyphae), C-, KC-, UV- (dull), ILugol’s-; psoromic acid.
Distribution and ecology: Neotropical, new to Galapagos and Ecuador; the few known specimens were collected in the humid zone of Santa Cruz, growing on both the endemic tree Scalesia pedunculata and the introduced trees Cinchona pubescens and Cedrela odorata, in semi-shaded to shaded and ±sheltered habitats.
Selected specimens examined: Ecuador: Galapagos: Isla Santa Cruz, along the road from Bellavista to Los Gemelos, 0°38’10”S, 90°23’45”W, alt. 579m, humid zone, on bark, 12-Feb-2006, Bungartz 3488 (CDS 27244), Aptroot 63826 (CDS 30384); along the road to Baltra, S of Los Gemelos, 0°38’44”S, 90°20’5”W, alt. 741 m, humid zone, on bark, 30-Nov-2006, Bungartz 5511 (CDS 36156); línea del Parque Nacional Galapagos, cerca de la finca de Galo Torres, 0°37’46”S, 90°24’0”W, alt. 570m, zona húmeda, sobre corteza, 30-Jun-2006, Nugra 17 (CDS 32670), Nugra 19 (CDS 32672); off the dirt road to Mina Granillo Rojo, on the N-side of the island, 0°37’2”S, 90°22’6”W, alt. 294m, transition zone, on bark, 21-Jun-2006, Bungartz 4972 B (CDS 29185).
from: Bungartz, F., Dútan, V. & Elix, J.A. (2013) The lichen genera Cryptothecia, Herpothallon and Helminthocarpon (Arthoniales) in the Galapagos Islands, Ecuador. The Lichenologist45(6): 1–24.