Diagnosis:—Sicut Megalospora porphyritis sed acidum usnicum continente differt.
Type:—ECUADOR. Galápagos: Isla Sán Cristóbal, trail from Cerro Pelado to El Ripioso, 0°52’S, 89°28’W, 392 m, transition zone, Psidium guajava forest with some old Hippomane mancinella trees and dense understory of Rubus niveus, Tournefortia rufosericea and Zanthoxylum fagara, on bark, S-exposed side of inclined Hippomane mancinella trunk (ca. 20 cm in diameter), semi-shaded, wind- and rain-sheltered, August 2008, Bungartz 8516 (holotype CDS-41162, isotype F).
Thallus yellowish grey to whitish grey, glossy, thick, uneven to slightly rugulose, up to 20 cm diameter. Soredia present, diffuse, starting out as coarse, corticated granules but soon becoming confluent and maculate. Apothecia round, 0.5–1.5 mm in diameter, up to 0.6 mm high, disc concave when young, becoming flat to slightly convex when mature, grey-black to black, glossy, epruinose. Margin prominent, thick, black. Excipulum brownish, K–. Epihymenium reddish brown, 10–20 μm thick. Hypothecium brown, 100–130 μm high. Hymenium 200–250 μm high, hyaline, strongly inspersed, amyloid. Ascospores single, hyaline, (3–)5-septate, 45–75 × 15–25 μm. Secondary chemistry: usnic acid and zeorin.
Distribution and habitat:—So far only known from the Galápagos Islands, found on both Santa Cruz and Sán Cristóbal Island in the transition and the humid zone.
Etymology:—The epithet refers to the known geographical range of the new species.
Additional specimen examined (paratype):—ECUADOR. Galápagos: Isla Santa Cruz, along the dirt road from Bellavista to Media Luna, Bungartz 3987 (CDS).
This species belongs in the Megalospora tuberculosa aggregate and could be included in that species in a wide sense (Sipman 1983). However, Harris (1984, 1986) reported that populations with pannarin instead of usnic acid, a sorediate thallus, and smaller ascospores represent an autonomous taxon which he recognized as M. porphyritis (Tuck.) R.C.Harris, a position adopted by other authors (Lücking 2007). The new species is intermediate between M. tuberculosa s. str. and M. porphyritis and represents a third species in this group. Thallus chemistry and the non-pruinose apothecia are as in M. tuberculosa s. str., but the (granular) soralia and the comparatively small ascospores with few septa recall M. porphyritis. The new species is potentially endemic to the Galápagos Islands, as no such material has yet been found among neotropical mainland populations of Megalospora.
from: Lumbsch, H.T., Ahti, T., Altermann, S., Amo De Paz, G., Aptroot, A., Arup, U., Bárcenas Peña, A., Bawingan, P.A., Benatti, M.N., Betancourt, L., Björk, C.R., Boonpragob, K., Brand, M., Bungartz, F., Cáceres, M.E.S., Candan, M., Chaves, J.L., Clerc, P., Common, R., Coppins, B.J., Crespo, A., Dal Forno, M., Divakar, P.K., Duya, M.V., Elix, J.A., Elvebakk, A.V., Fankhauser, J., Farkas, E., Ferraro, I.L., Fischer, E., Galloway, D.J., Gaya, E., Giralt, M., Goward, T., Grube, M., Hafellner, J., Hernández M., J.E., De Los Ángeles Herrera Campos, M., Kalb, K., Kärnefelt, I., Kantvilas, G., Killmann, D., Kirika, P., Knudsen, K., Komposch, H., Kondratyuk, S., Lawrey, J.D., Mangold, A., Marcelli, M.P., Mccune, B., Messuti, M.I., Michlig, A., Miranda Gonzáles, R., Moncada, B., Naikatini, A., Nelsen, M.P., Øvstedal, D.O., Palice, Z., Papong, K., Parnmen, S., Pérez-Ortega, S., Printzen, C., Rico, V.J., Robayo, J., Rosabal, D., Ruprecht, U., Salazar Allen, N., Sancho, L., Santos De Jesus, L., Santos Vieira, T., Schultz, M., Seaward, M.D.R., Sérusiaux, E., Schmitt, I., Sipman, H.J.M., Sohrabi, M., Søchting, U., Søgaard, M.Z., Sparrius, L.B., Spielmann, A., Spribille, T., Sutjaritturakan, J., Thammathaworn, A., Thor, G., Thüs, H., Timdal, E., Truong, C., Türk, R., Umaña Tenorio, L., Upreti, D.K., Van Den Boom, P., Vivas Rebuelta, M., Wedin, M., Will-Wolf, S., Wirth, V., Wirtz, N., Yahr, R., Yeshitela, K., Ziemmeck, F. & Lücking, R. (2011): One hundred new species of lichenized fungi: a signature of undiscovered global diversity. Phytotaxa 18: 1-127.