The Family Cladoniaceae (Lecanorales) in the Galapagos Islands Author Yánez-Ayabaca, A. Biodiversity Assessment, Charles Darwin Foundation (AISBL), Puerto Ayora, Santa Cruz, Galapagos, Ecuador, * Corresponding author: F. Bungartz, phone: + 593 - 5 2526146 / 47 ext. 218, fax: + 593 - 5 2527013 ext. 103, email: frank. bungartz @ fcdarwin. org. ec Universidad Central del Ecuador, Quito, Ecuador, email: albayanez 8 @ gmail. com Author Ahti, T. Botanical Museum, Finnish Museum of Natural History, P. O. Box 7, FI- 00014 University of Helsinki, Finland, Author Bungartz, F. Biodiversity Assessment, Charles Darwin Foundation (AISBL), Puerto Ayora, Santa Cruz, Galapagos, Ecuador, * Corresponding author: F. Bungartz, phone: + 593 - 5 2526146 / 47 ext. 218, fax: + 593 - 5 2527013 ext. 103, email: frank. bungartz @ fcdarwin. org. ec Universidad Central del Ecuador, Quito, Ecuador, email: albayanez 8 @ gmail. com text Phytotaxa 2013 129 1 1 33 https://www.mendeley.com/catalogue/f9153903-31d2-31bc-a0c2-f33d3829b86c/ journal article 10.11646/phytotaxa.129.1.1 1179-3163 5085561 Cladonia confusa R. Sant. (1942: 13) = C. galapagosensis Ahti (1961:46) ; according to Ahti (2000) . ( Figs. 3a–d ) Primary thallus evanescent; podetia forming cushions, 4–12 cm tall; densely branched; branching pattern mainly isotomic trichotomous, rarely dichotomous, therefore not forming distinct principal axes; axils frequently perforate; tips slender; surface ecorticate, slightly verruculose; algal clumps (glomerules) visible in old podetia; pycnidia with hyaline jelly; apothecia pale brown, uncommon. Notes : Cladonia confusa is the most common reindeer lichen in Galapagos . Superficially similar species are C. arbuscula subsp. boliviana and C. arcuata . Because of its growth form, Cladia aggregata could also be mistaken for a reindeer lichen. For differences see the notes for these species. Two forms can be distinguished according to their color and the presence, respective absence of usnic acid: Cladonia confusa f. bicolor (Müll. Arg.) Ahti & DePriest (2001: 501) ( Figs. 3a–b ) Podetia ash gray to brownish gray, often with dark brown tips. Spot tests and chemistry : P−, K−, C−, KC−, UV+ bright greenish white; with perlatolic acid only. Distribution and ecology : Know from Fernandina, Isabela, San Cristóbal, Santa Cruz Island; less common than C. confusa f. confusa , but both forms often growing side by side; most specimens collected from the humid zone, but occasionally also found in the transition zone, or rarely even in the dry zone; when well developed forming extensive reindeer lichen heaths. Selected specimens examined : ECUADOR . GALAPAGOS : Isabela Island , Volcán Darwin , Tagus Cove , 800 m , humid zone, on large masses 1 ft or more in diam. on lava, 24 Mar 1906 , Stewart, A. 430 ( CAS-DS 640479 ), Cerro Beagle , 15 June 1984 , Luong, T.T. ( CDS 10886), southwestern slope, above Tagus Cove, 0°13’43.29”S , 91°19’47.3”W , 724 m , transition zone, on soil, 12 Nov 2007 , Ertz, D. 11797 ( CDS 37156) . Santa Cruz Island , at the base of the eastern slope below the summit of El Puntudo , 0°38’42”S , 90°20’14”W , 780 m , humid zone, on soil, 28 Feb 2006 , Bungartz, F. 3986 ( CDS 27916), summit area NW of La Copa (= Media Luna), 830 m , humid zone, in bottom of a small crater, 18 Feb 1964 , Horneman, S . [distributed as Weber, Lich. Exs. no. 106 ( COLO 185828 , LSU , M, NY)] .