Cladonia dactylota Tuck. (1859: 201)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 16-17

Cladonia dactylota Tuck. (1859: 201)

( Fig. 4c–d )

Primary thallus persistent, of abundant, usually ± erect and rather thick squamules, typically densely cottony sorediate on their lower surface, epruinose; podetia common, greenish gray, sometimes with dark brown necrotic parts, often elongated, 0.8–1.5 (–2.5) cm tall, unbranched to slightly branched; axils closed; tips commonly with narrow and irregular scyphi that sometimes present small marginal proliferations, rarely ascyphose and then acute; surface completely corticate and densely sorediate, soredia farinose, developing into distinctly delimited tuberculose soralia, generally forming bellow the scyphi, less commonly also along the podetial stalk; macrosquamules absents from the podetia, restricted to the basal squamules of the primary thallus; pycnidia with hyaline jelly, apothecia with brown jelly.

Spot tests and chemistry: P+ golden yellow, K-, C-, KC-, UV-; psoromic acid and traces of 2’- O - demethylpsoromic and fumarprotocetraric acid.

Distribution and ecology: New to Galapagos; reported here from Isabela, Pinta, San Cristóbal, Santa Cruz, and Santiago Island; a common species in the humid zone, sometimes also found in the transition zone; on soil or rock and often among plant debris.

Notes: The species can easily be recognized by its tuberculose soralia with abundantly farinose soredia in combination with a very characteristic P+ golden yellow spot test reaction caused by psoromic acid. The primary thallus of the species is also very distinct with its stout, ± erect squamules that have a cottony sorediate lower surface. The species can thus even be identified if its podetia are missing.

Sepected specimens examined: ECUADOR. GALAPAGOS: Isabela Island, Volcán Alcedo, on crater rim NW of hut at highest point, 0°25’51”S, 91°5’16”W, 1190 m, humid zone, on soil, 5 May 2006, Aptroot, A. 64830 ( CDS 31405) . Pinta Island, on top of the highest point of the island, 0°35’3”N, 90°45’12”W, 625 m, humid zone, on rock and plant debris, 26 Feb 2007, Bungartz, F. 5748 ( CDS 33402) . San Cristóbal Island, NE-slope of Cerro San Joaquín , shortly below the summit, 0°53’50.79”S, 89°30’49.7”W, 693 m, humid zone, on bryophytes, 24 Aug 2008, Bungartz, F. 8587 ( CDS 41233) . Santa Cruz Island, near Puntudo , 0°38’41”S, 90°20’13”W, 750 m, humid zone, on soil, 27 May 2005, Aptroot, A. 63169, 63202 ( CDS 29900, 29933 ) . Santiago Island, Coscojo , 0°13’12”S, 90°45’45”W, 725 m, transition zone, on soil, 24 Mar 2006, Aptroot, A. 65567 ( CDS 32155) .

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).