Cladonia confusa R. Sant. (1942: 13)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 12

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)] .

Figures

FIGURE 3. a–c Cladonia confusa. a thalli of both forms growing side by side, upper pale greenish yellow thallus of C. confusa f. confusa, lower, white thallus with brownish tinge of C. confusa f. bicolor (Bungartz 3985, 3986, scale 10 mm); b close-up of C. confusa f. bicolor, the epithet bicolor justified by the more brownish, sun-exposed parts and the whitish pale underside of the podetia (Bungartz 3986, scale 3 mm); c close-up of the UV+ chemotype of C. confusa f. confusa, the inset shows a predominantly trichotomous branching pattern and an arachnoid granular surface of the podetia (Nugra 261, scale 3 mm); d close-up of the UV– chemotype of C. confusa f. confusa, the inset shows a predominantly dichotomous branching pattern with a uneven podetial surface (Cavagnaro 26, scale 3 mm); e Cladonia corniculata (Sipman L-45, scale 5 mm); f Cladonia corymbites (Bungartz 8334, scale 3 mm).