Cladonia corymbosula Nyl. (1876a: 560)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 16

Cladonia corymbosula Nyl. (1876a: 560)

( Fig. 4a–b )

Primary thallus persistent, of short-laciniate, thick squamules, surface scarcely pruinose, rugulose and cracked, esorediate; podetia rare, grayish green, small, 0.6–1.7 cm tall, terete to ± flattened, hyphae of the stereome relatively loose (not compact) and frequently with longitudinal cracks; tips clavate, unbranched to moderately branched, ascyphose, typically bearing closely aggregated, “turban-like” apothecia; surface ecorticate, densely sorediate-granulose; microsquamules absent; pycnidia not seen; apothecia pale brown, globular and closely aggregated and thus resembling a “turban”.

Spot tests and chemistry: P+ orange red, K-, C-, KC-, UV-; fumarprotocetraric acid.

Distribution and ecology: A new record for Ecuador and the Galapagos Islands. Currently known from Isabela, Santiago, and Santa Cruz Island; known from the humid zone only, on rock or thin soil; possibly quite rare, but the basal squamules lacking the characteristic podetia might be overlooked.

Notes: The species can easily be recognized by its relatively short podetia topped by closely aggregated, “turban-like” apothecia. The species could be mistaken for C. peziziformis , which has similarly aggregated apothecia. Cladonia peziziformis , however, has corticate podetia, its cortex peeling off in relatively large squamules. In contrast, podetia of C. corymbosula are ecorticate, and typically sorediate; they always lack squamules. Despite previous reports, Cladonia peziziformis cannot be confirmed for the Galapagos and the reports are almost certainly based on misidentifications of C. corymbosula .

Material lacking podetia is not uncommon and can often be identified if compared to the squamulose primary thalli of specimens that bear podetia. It is generally difficult, however, to distinguish clear cut characters that help identify these specimens when the characteristic podetia are missing.

Selected specimens examined: ECUADOR. GALAPAGOS: Isabela Island, Volcán Alcedo, on the crater rim near the hut, 0°26’33”S, 91°5’31”W, 1100 m, humid zone, on rock, 3 July 2006, Aptroot, A. 65262 ( CDS 31848) . Santa Cruz Island, near Los Gemelos craters, 0°36’31”S, 90°22’4”W, 350 m, humid zone, on soil, 31 May 2005, Aptroot, A. 63384 ( CDS 30130) . Santiago Island, summit of Cerro Gavilán , inner N- and NEexposed crater rim, 0°12’20”S, 90°47’3”W, 840 m, humid zone, on rock, 23 Mar 2006, Aptroot, A. 65721 ( CDS 32313) .

Figures

FIGURE 4. a–b Cladonia corymbosula. a basal squamules (Bungartz 4129, scale 5 mm); b podetia with turban-like apothecia (Aptroot 65255, scale 3 mm); c–d Cladonia dactylota; c atypical, because unusually well-developed podetia (Aptroot 64643, scale 5 mm); d close–up of characteristic squamules (Aptroot 64667, scale 5 mm). e predominantly microsquamulose podetia of Cladonia didyma (Bungartz 4109, scale 5 mm); f tiered podetia of Cladonia grayi (Bungartz 8344, scale 5 mm).