Galapagos Species Database

Thallus saxicolous; initially placodioid leprose, i.e., developing upon a common, shared hypothallus (structurally similar to L. vouauxii), but soon becoming leprose-fruticose by the formation of ill-defined pseudopodetia that lack a distinct axial strand, prothallus fine, inconspicuous, main thallus of distinctly delimited, granules soon budding into branched gnarled, pseudocorticate pseudopodetia; surface white to pale yellowish or grenish ivory white; hypothallus inconspicuous, exposed only as a fine prothallus along the thallus margin; rhizohyphae absent or at least indistinct; granules pseudocorticate, very compact, coarse [(157–)170–185(–200) µm in diam., rather uniform in size], aggregating into erect, coarse (0.8–)3–5(–11.5) mm tall pseudopodetia, without conspicuous extruding hyphae, immature or damaged, or eroded parts rarely with few protruding hyphae. Photobiont green, coccoid. Spot tests and chemistry: P+ reddish orange, K+ yellow orange, C+ red, KC−; UV(dark); atranorin, lecanoric acid, pannaric acid 6­methyl ester and accessories. Distribution and ecology. Neotropical, rare in the dry and lower transition zone, most common in the upper transition and humid zone, with few specimens collected in the high altitude dry zone; typically growing on rock, rarely on soil, then often overgrowing mosses or detritus, rarely on wood and very rarely on bark; typically in ±sheltered, shaded habitats, below overhangs or on vertical rock faces and cliffs, rarely in ±exposed situations, but then usually not receiving direct sunlight. Notes. In the Galapagos the only other species with dibenzofurans is L. vouauxii. Both L. tenella and L. vouauxii lack a well defined hypothallus and the immature thalli of L. tenella which have not developed pseudopodetia, can be strikingly similar to the coarsely granular thalli of L. vouauxii. Both species have compact, pseudocorticate granules that are largely devoid of extruding hyphae, although individual granules of L. tenella are generally much larger than those of L. vouauxii.