Cladonia arcuata Ahti (1961: 73)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 6-8

Cladonia arcuata Ahti (1961: 73)

( Figs. 1e–f )

Primary thallus evanescent; podetia forming cushions, mostly whitish gray but apical branches darkening, becoming distinctly brown towards their tips, 4−5 cm tall; branching pattern anisotomic, dichotomous, occasionally trichotomous, main axes distinguishable; axils close or rarely perforate; apical branches usually deflexed, tips sometimes melanotic; surface ecorticate, slightly verruculose; pycnidia with red jelly; apothecia with pale brown jelly.

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

Distribution and ecology: Known only from Isabela, Santa Cruz, and San Cristóbal Island; from the humid zone extending down into the upper transition zone; on the ground in open vegetation like sparse forests or open scrub, fern-sedge grasslands and reindeer lichen heaths; on soil and amongst plant debris and bryophytes, also on rock.

Notes: Cladonia arcuata has a similar morphology to C. confusa f. bicolor , however that species does not have pycnidia with red jelly and always reacts P−, because it lacks fumarprotocetraric acid.

Selected specimens examined: ECUADOR. GALAPAGOS: Isabela Island, Volcán Cerro Azul, S slope above Iguana Cove , 750 m, humid zone, exposed rocky place in fern-sedge vegetation, 22 June 1976, Sipman, H. J.M. L-35 ( COLO 297926 ) ; Volcán Darwin, southwestern slope, above Tagus Cove , 0°13’34”S, 91°19’21.4”W, 840 m, transition zone, on soil between plant debris, 13 Nov 2007, Bungartz, F. 7495 ( CDS 37986) ; Volcán Sierra Negra, close to the southern crater rim, along the trail to Alemania , 0°51’12.69”S, 91°8’40.5”W, 1055 m, humid zone, on plant debris, 16 Aug 2008, Bungartz, F. 8341 ( CDS 40987) . San Cristóbal Island, Cerro San Joaquín , 0°53’49.5”S, 89°30’47.7”W, 691 m, humid zone, among mosses on the ground, 24 Aug 2008, Truong, C. 1512 ( CDS 39823) . Santa Cruz Island, 200 m, transition zone, 1 Apr 1964, Horneman, S. ( COLO 316717 ) .

Cladonia bungartzii Yánez-Ayabaca & Ahti sp. nov. MycoBank no. 804595 Diagnosis: A C. macilenta et C. didyma stereomate non compacte instructa differt. Holotype:— ECUADOR. GALAPAGOS: Pinta Island, on top of the highest point of the island, 0°35’3”N, 90°45’12”W,

625 m, humid zone, low and dense vegetation of ferns, grasses ( Cyperus andersonii ), and Lycopodium sp. , open N-

exposed, soil semi-shaded by ferns and Lycopodium sp ; wind- and rain-exposed, on soil, 26 Feb 2007, Bungartz, F.

5744 (CDS 33396) ( Figs. 2a–b )

Primary thallus subpersistent, thin, of short squamules with a corticate upper side and densely granularsorediate lower side, epruinose; podetia common, stout, 0.5–2cm tall, composed of densely interwoven hyphae, but not compact, and frequently with longitudinal cracks, pale yellow, simple or slightly branched, mainly near the tips; surface mostly corticate-verruculose, sometimes with denuded areas where the cortex disintegrates and there farinose sorediate; lacking microsquamules; pycnidia not seen; apothecia often small, with bright red jelly.

Spot tests and chemistry: P+ yellow, K+ yellow, C−, KC−, UV−; thamnolic and traces of didymic acid.

Distribution and ecology: Known only from the humid zone of Pinta Island, where the species grows on soil of the fern-sedge grasslands (e.g., Cyperus andersonii , Lycopodium sp. ).

Notes: In Galapagos Islands, this species can be confused with C. macilenta , both species are densely sorediate, however C. macilenta has ecorticate podetia with few microsquamules. Cladonia didyma is another species that also has red apothecia, but it is different of C. bungartzii because its podetia are ecorticate covered with abundant microsquamules. Both C. macilenta and C. didyma have compact, dense stereomes that typically lack longitudinal cracks that are very characteristic of C. bungartzii .

Additional specimen examined (paratype): ECUADOR. GALAPAGOS: Pinta Island, on top of the highest point of the island, 0°35’3”N, 90°45’12”W, 625 m, humid zone, on open soil, 26 Feb 2007, Bungartz, F. 5749 ( CDS 33403) .

Figures

FIGURE 1. a–b Cladia aggregata (Bungartz 3971). a bifurcate apices of the pseudopodetia (scale 5 mm); b close-up with characteristic oval perforations (scale 3 mm). c–d Cladonia arbuscula subsp. boliviana (Bungartz 8338). c general thallus aspect (scale 5 mm); d podetial apices showing the predominantly anisotomic dichotomous branching pattern (scale 5 mm). e–f Cladonia arcuata (Bungartz 7495); e general thallus aspect (scale 3 mm); f podetial apices showing the predominantly isotomic dichotomous branching pattern (scale 2 mm).

FIGURE 2. a–b Cladonia bungartzii (holotype, Bungartz 5744); a general thallus aspect (scale 2 mm); b close-up of the podetia (scale 1 mm); c general thallus aspect of Cladonia cartilaginea (Nugra 240, scale 5 mm); d general thallus aspect of Cladonia ceratophylla (Bungartz 5604, scale 5 mm); e–f cone-shaped, granulose-sorediate podetia of Cladonia chlorophaea; e (Bungartz 8223, scale 5 mm); f (Bungartz 6614, scale 5 mm).