nonHerpothallon hyposticticum F. Seavey & J. Seavey (non Bungartz & Elix) nom. illegit.
MycoBank no. 804739
Diagnosis: Herpothallon with thin to moderately thickened dense, contiguous to rimose thallus, granular to cylindrical, sparsely branched pseudisidia, containing hypostictic and hyposalazinic acid.
Type: Ecuador. Galapagos Islands: Isla Santa Cruz, near the CDRS field-weather station below the summit of Cerro Crocker, 0°38’35”S, 90°19’42”W, humid zone, much overgrown with dead Cinchona pubescens trees (killed by invasive species program), N-exposed slope, on trunks and twigs of dead Cinchona pubescens, 28-Dec-2005, Bungartz 3306 (CDS 26961-holotype).
Thallus corticolous, rarely saxicolous, delimited by an inconspicuous, dense prothallus of white hyphae; thallus surface grayish white, with storage ±beige to pale yellowish, ecorticate, thin and arachnoid to moderately thickened and then developing a dense, compact, contiguous to sparsely fissured or even distinctly rimose surface, sparsely to abundantly covered by minutely granular, powdery to distinctly cylindrical pseudisidia, 50-80 µm in diam., fairly uniform in size; medulla white, filled with few, sparse calcium oxalate crystals (insoluble in KOH, forming colorless, needle-shaped crystals in 25% H2SO4); asci not observed; pycnidia not observed.
Spot tests and chemistry: P-, K+ yellow, KC-, C-; UV+ bright yellow; medulla ILugol’s + weakly blue in parts; hypostictic and hyposalazinic acid.
Distribution and ecology: Currently known only from Galapagos; occuring from the upper transition to the humid zone, on native or endemic (Pisonia floribunda, Zanthoxylon fagara, Scalesia pedunculata) and introduced tree species (Cinchona pubescens, Persea americana), in semi-shaded to shaded, ±sheltered habitats; on specimen from a shaded rock overhang.
Notes: Herpothallon hyposticticum is unusual in several aspects. Specimens consistently contain hypostictic and hyposalazinic acid, substances that are usually accessories of stictic acid and norstictic acid, yet these principal metabolites are absent from the thalli. The species is morphologically unusually variable. Some thalli are abundantly covered in well developed pseudisidia, whereas the thallus itself is poorly developed, essentially present only as thin layer of arachnoid hyphae. In other specimens the thallus is better developed, cottony to dense, ±compacted and then sparsely fissured. These specimens generally have pseudisidia that are much less developed, in some parts of the thallus they remain in fact granular and thus look like granular soredia. In other parts of the same thallus these granules nevertheless become cylindrical and even sparsely branched, indicating that they are all precursors of true pseudisidia. Finally some specimens have an unusually well developed, sometimes almost rimose thallus and generally only develop granular pseudisidia. All specimens have a weakly I+ blue medulla, at least in part. Specimens with well developed thalli and poorly developed pseudisidia are superficially similar to species of Cryptothecia, but when elevated regions of the thallus, thought to perhaps correspond to ascigerous areas, were sectioned, no asci or acospores could be found.
Specimens examined: Ecuador: Galapagos: Isla Isabela, Volcán Alcedo, on top of the crater rim, 0°27’33”S, 91°6’49”W, alt. 1051m, humid zone, on bark, 05-Mar-2006, Bungartz, F. 4105 (CDS 28073); Isla Santa Cruz, 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 A (CDS 44662); 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 3489 (CDS 27245); línea del Parque Nacional Galápagos, cerca de la finca de Galo Torres, 0°37’45.77”S, 90°24’0”W, alt. 570m, zona húmeda, sobre corteza, 30-Jun-2006, Nugra 13 A (CDS 38749), Nugra 20 B (CDS 54431); Isla Santiago, summit of Cerro Gavilan, inner N- and NE-exposed crater rim, 0°12’20”S, 90°47’3”W, alt. 840m, humid zone, on rock, 23-Mar-2006, Aptroot 65713 (CDS 32305).
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.