Cladonia pulverulenta (L. Scriba ex Sandst.) Ahti (2000: 145)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 21-23

Cladonia pulverulenta (L. Scriba ex Sandst.) Ahti (2000: 145)

( Fig. 5e )

Primary thallus persistent, of elongate squamules, upper side sometimes coarsely pruinose along the margin or covering the entire squamules, esorediate; podetia common, greenish gray or pale yellow, with dark brown necrotic basal parts, slender, elongate; 0.8–2.5 cm tall, simple to sparsely branched, tips blunts, rarely scyphose; scyphi, if present, narrow; surface corticate at the base with cortex extending up to 1/3 or 2/3 of the stalk, typically covered by granules, microsquamules, schizidia and farinose soredia as a result of cortex disintegrations; pycnidia hyaline, apothecia with brown jelly.

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

Distribution and ecology: New record for Ecuador and Galapagos. Known from Isabela, San Cristóbal, Santa Cruz, and Santiago Island. Ahti (2000) reported this species only from the West Indies and Central America, but it is more widespread, having been confused with C. ochrochlora . A common species in Galapagos; widely distributed through the humid zone, rarely also found in the transition or dry zone, on the ground or as epiphyte.

characteristic of Cladonia pyxidata (Aptroot 64846, scale 3 mm).

Notes: This species is very similar to C. aff. ramulosa ; C. granulosa , and C. polyscypha ; all have a very similar general morphology of relatively tall and slender podetia with blunt or narrowly scyphose tips. Only C. polyscypha is consistently scyphose and never has blunt apices.

Cladonia aff. ramulosa , when well developed, has very irregular cups, sometimes even ± broadened and typically with abundant proliferations. As a result these specimens of C. aff. ramulosa have an overall much more “disheveled look”, but this species is highly variable and less well developed material is often hard to distinguish from the other species. All other species, if scyphose, are generally characterized by very narrow cups that are just barely wider than the stalk and their scyphi have no, or only extremely short proliferations. Cladonia aff. ramulosa is also the only species that is extensively corticate with few denuded areas, where the cortex flakes off forming microsquamules. All other species are not as extensively corticate. Both, C. pulverulenta and C. polyscypha have podetia that become increasingly blackened and die off at their base (necrotic), a character not observed in the other two species. In C. pulverulenta basal cortication typically covers at least 2/3 of the stalk and only then begins to disintegrate into irregular parts peeling off as schizidia. Its surface also develops microsquamules, granules, or even farinose soredia. In contrast, C. polyscypha is less corticate, the cortex does not peel or flake off but develops into few distinct microsquamules or granules, soredia are rare.

These similar species all contain fumarprotocetraric acid, only C. granulosa contains thamnolic acid instead.

Selected specimens examined: ECUADOR. GALAPAGOS: Isabela Island, Volcán Sierra Negra, along dirt road from Puerto Villamil to crater of Sierra Negra , farmland, 0°51’39.89”S, 91°1’41.60”W, 330 m, humid zone, on wood, 9 Sept 2007, Bungartz, F. 6928 ( CDS 36427) , Villamil , 120 m, dry zone, rocks and dead wood, 6 July 1905, Stewart, A. 428 (336) ( CAS-DS 640540 ) ; Volcán Alcedo, outer E-exposed slope just below the crater rim, 0°25’17”S, 91°5’8”W, 1077 m, humid zone, on bark, 8 Mar 2006, Aptroot, A. 65127 ( CDS 31709) . San Cristóbal Island, sector of the "Gotera de agua", trail to Cerro Pelado , 0°51’40.60”S, 89°27’37.20”W, 397 m, transition zone, on bark, 23 Aug 2008, Truong, C. 1493 ( CDS 39804) . Santa Cruz Island, near Horneman farm, humid zone, on bark, 20 Aug 2008, Truong, C. 1341 ( CDS 39652) . Santiago Island, along the trail from Cerro Gavilán to La Central, 0°13’2”S, 90°46’33”W, 890 m, humid zone, on soil, 24 Mar 2006, Bungartz, F. 4830 A ( CDS 29004) .

Figures

FIGURE 5. a the predominantly sorediate podetia of Cladonia macilenta (Bungartz 7758, scale 3 mm); b highly dissected, minute squamules with very short podetia, characteristic of Cladonia nana (Aptroot 64501, scale 5 mm); c–d Cladonia polyscypha. c general growth aspect (Bungartz 3970, scale 5 mm); d close-up with podetia terminating in narrow scyphi (Aptroot 64514, scale 5 mm); e podetia of Cladonia pulverulenta (Aptroot 64518, scale 5 mm); f broad, trumpet-shaped podetia with coarse corticate granules