Small island but great diversity: thirty six species of Parmotrema (Parmeliaceae, lichenized Ascomycota), including sixteen new species, on Réunion (Mascarenes), with additional data from the Western Indian Ocean Author Masson, Didier 0000-0002-3340-5472 Vertevoye, 2860 route d’Irieu, F- 40390 Saint-Martin-de-Seignanx, France di. masson @ wanadoo. fr; https: // orcid. org / 0000 - 0002 - 3340 - 5472 di.masson@wanadoo.fr Author Magain, Nicolas 0000-0001-5409-9518 Evolution and Conservation Biology, InBios research centre, Sart Tilman B 22, Quartier Vallée 1, Chemin de la vallée 4, B- 4000 Liège, Belgium nicolas. magain @ uliege. be; https: // orcid. org / 0000 - 0001 - 5409 - 9518 nicolas.magain@uliege.be Author Sérusiaux, Emmanuël 0000-0002-3340-5472 Vertevoye, 2860 route d’Irieu, F- 40390 Saint-Martin-de-Seignanx, France di. masson @ wanadoo. fr; https: // orcid. org / 0000 - 0002 - 3340 - 5472 & Evolution and Conservation Biology, InBios research centre, Sart Tilman B 22, Quartier Vallée 1, Chemin de la vallée 4, B- 4000 Liège, Belgium e. serusiaux @ uliege. be; https: // orcid. org / 0000 - 0002 - 0456 - 0131 * Corresponding author & Vertevoye, 2860 route d’Irieu, F- 40390 Saint-Martin-de-Seignanx, France di. masson @ wanadoo. fr; https: // orcid. org / 0000 - 0002 - 3340 - 5472 di.masson@wanadoo.fr text Phytotaxa 2024 2024-06-27 657 1 1 138 http://dx.doi.org/10.11646/phytotaxa.657.1.1 journal article 10.11646/phytotaxa.657.1.1 1179-3163 13217474 Parmotrema nephophilum D.M. Masson & Sérus. , sp. nov. MycoBank no. 853874 Diagnosis. Similar to Parmotrema crinitum , but differs by the longer conidia (6–9 vs 5–6 µm) and by the various vegetative propagules produced: marginal and submarginal isidia that mostly develop early into phyllidia, conspicuous branched laciniae, and occasional granular soredia. Holotype :— FRANCE . Réunion : Saint-Joseph , Piton du Rond , elev. 1370 m , 21°17’57”S , 55°36’27”E , in leeward montane rainforest, on ± mossy bark of trunk of Dombeya sp. , 18 August 2013 , D. Masson 974.4310 (MNHN-PC-PC0088077; isotype : LG). GenBank accession number: ITS ( PP 840570). ( Fig. 29 ) Thallus foliose, moderately adnate, membranaceous, rarely subcoriaceous, up to 13 × 20 cm . Lobes irregularly branched, contiguous to imbricate, 3–14 mm wide, irregularly wrinkled; with margins sinuate, denticulate to laciniate, occasionally lobulate, ± ciliate ( Fig. 29D ). Cilia black, rare to numerous, irregularly distributed at the margin of the lobes, lobules, laciniae, on isidia, phyllidia, and isidioid outgrowths of the amphithecium, mostly simple, sometimes 1–3 times branched, rarely slightly squarrose, ca. 0.03–0.06 mm in diameter at the base, up to 3.5 mm long. Upper surface pale greenish grey, sometimes more yellowish towards the periphery, ± shiny, faintly to clearly white-maculate, ± undulating, smooth to rugulose, becoming finely cracked centrally, laciniate, isidiate and/or sorediate, lacking schizidia, pustules, dactyls. Isidia generally present, mostly at the margin of lobes and laciniae, more rarely submarginal or laminal, first granular or ± cylindrical and terete, ciliate or not, rarely erumpent, rapidly developing into ± branched and ciliate phyllidia of variable size. Laciniae marginal, usually numerous and conspicuous ( Fig. 29E ), ciliate, repeatedly branched, ± elongated, sometimes partly canaliculate, up to 10 mm long, 0.2–2 mm wide, ± clumping, fragile when well developed, at times isidiate or sorediate. Soralia rare, present in 9 of the 71 thalli examined, mostly terminal on marginal teeth or short laciniae, more rarely laminal and ± erumpent and orbicular in the submarginal zone of the lobes ( Fig. 29F ). Soredia granulose, (40)– 54.6 –(70) µm in diameter (n = 90, from 3 specimens , SD = 7.4 µm). Lobules occasional, marginal, up to 5 × 6 mm . Medulla white throughout. Lower surface rugulose or granulate, rarely smooth, shiny at the periphery of the thallus, duller towards the centre; black to the margin, or with a buff or chestnut brown, erhizinate or sparsely rhizinate, marginal zone (ca. 1–6 mm wide) at main lobe tips, lateral lobes with vegetative propagules or apothecia with an erhizinate, ivory white or ivory-mottled marginal zone ( 0.5–5 mm wide). Rhizines generally rather numerous, unevenly distributed, concolor to the lower surface, simple, rarely 1–2(3) times branched or squarrose, up to 2.5 mm long. Apothecia rare (fertile thalli found in 8 localities out of 51), submarginal, cupuliform, ± flattening with age, up to 11 mm in diameter, stipitate on ± swollen stipes (up to 3 mm in diameter); disc imperforate, orange brown, concave, initially shiny and smooth, then ± rough and dull; margin crenate, early with ± flattened protuberances evolving either into soralia or, more frequently, into variable combinations of ± branched isidia, isidioid outgrowths or laciniae, ciliate or not, which extend on the amphithecium and stipe with age; amphithecium and stipe distinctly white-maculate; hymenium s. lat. (88)– 106.6 –(125) µm high, proper exciple with a hyaline layer very thin, not clearly distinct from subhymenium, intermediate layer (10)– 14.4 –(17) µm high, cortex-like basal layer (20)– 30.5 –(38) µm high. Ascospores 8 per ascus, simple, colourless, broadly ellipsoidal to ellipsoidal, (22)23– 28.3 –33.5(34) × 13– 15.9 –18.5(19) µm, Q = (1.35)1.49– 1.79 –2.09, epispore (3)– 3.5 –(4.5) µm thick, n = 150, from 5 thalli, mean values for each thallus: 30.1 × 16.9, 30.0 × 16.7, 28.2 × 15.8, 27.6 × 14.9, 25.6 × 15.0 µm. Pycnidia fairly rare, mostly submarginal on lobes, but also on laciniae, black. Conidia bacilliform 6–9 × ca. 1 µm. Upper cortex palisade plectenchymatous, fragile, (18)– 21.8 –(25) µm thick. Algal layer ± continuous, (8)– 13.1 –(18) µm thick. Medulla (74)– 95.0 –(104) µm thick. Lower cortex prosoplectenchymatous, (14)– 16.3– (18) µm thick. Chemistry :— Spot tests and fluorescence : upper cortex K+ yellow, UV−; medulla K+ yellow, C− , KC− , P+ orange, UV−. Secondary metabolites ( TLC ): upper cortex with atranorin and chloroatranorin; medulla with stictic acid (major), constictic acid (minor), menegazziaic acid (trace), cryptostictic acid (trace) and hypostictic acid (trace). Etymology :—The specific epithet is derived from the Greek nephos (cloud) and philos (having affinity for), in reference to the cloud forests where the species grows. Geographical distribution :—Currently known only from Réunion , where it seems to be quite common and widespread between 685 and 1835 m elevation. It was found in at least 52 locations in 42 UTM 1× 1 km grid cells (or 33 UTM 2× 2 km grid cells, Fig. 29A & 29B ), in the Piton des Neiges massif as well as in the Piton de la Fournaise massif. The earliest collection dates to 1840. Ecology :— Parmotrema nephophilum is a mainly corticolous lichen (90% of the mentions), but thalli can also occasionally grow on volcanic rocks and, very rarely, on wood. When corticolous, it was found on trunks (63% of the mentions) as well as branches (37%), the observed difference in frequency being not statistically significant (n = 51, χ² = 3.31, P = 0.069). The phorophytes are diverse ( Aphloia , Badula , Cinnamomum , Claoxylon , Cyathea , Dombeya , Ficus , Geniostoma , Hypericum , Nuxia , Phyllanthus , Sideroxylon , Weinmannia ), the most frequent being trees of the genus Dombeya (21% of the mentions). Montane rainforests are the main habitat that the species occurs in (71% of the localities), followed by submontane rainforests (24%). Pandanus wet thicket and camphor tree plantation are more marginal habitats (2% each). The species occurs equally on windward and leeward slopes. The bioclimate of the localities is pluvial tropical; thermotype belts are mainly mesotropical = from upper thermotropical to upper mesotropical (355 ≤ It ≤ 567), ombrotype belts are variable = from lower humid to ultrahyperhumid (7.8 ≤ Io ≤ 29.0) ( Fig. 29C ). FIGURE 29. Parmotrema nephophilum . A : Distribution of the isidiate/phyllidiate/laciniate form on Réunion (UTM 2×2 km grid system); B : Distribution of the sorediate form on Réunion (UTM 2×2 km grid system); C : Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al . 2011: 17–18 ), light dotted: only sorediate form, medium dotted: only isidiate/phyllidiate/laciniate form, heavy dotted: both forms; D : Gross morphology of thallus (holotype); E : Heavily phyllidiate/laciniate lobe (holotype); F : Sorediate lobe with marginal and submarginal soralia and granulose soredia ( Masson 974.4716 ). Scale bars: A, B = 10 km; D = 10 mm; E = 4 mm; F = 2 mm. Notes :—This taxon is puzzling because of the variability of vegetative propagules present from one thallus to another, or even within the same thallus. Two main forms can be distinguished. The most common one has a variable combination of isidia/phyllidia and branched laciniae that are easily shed. When the laciniae are poorly developed, this form may be mistaken for an atypical Parmotrema crinitum ; when they are predominant, which is the most frequent case, it resembles P. eliasaroanum Benatti, Marcelli & Elix , a Brazilian species, or P. laciniatulum Krog , a Tanzanian species. Parmotrema crinitum , P. eliasaroanum and P. nephophilum share the same medullary chemistry, the stictic acid complex, but P. eliasaroanum differs in lacking menegazziaic acid ( Marcelli et al . 2008 ). In addition, P. eliasaroanum differs from P. nephophilum by the complete absence of isidia and by the slightly smaller size of the ascospores. Compared to P. nephophilum , P. laciniatulum lack isidia, its conidia are sublageniform and its medulla contains alectoronic and α-collatolic acids instead of the stictic acid complex ( Krog 1991 ). A sorediate form has also been encountered, more rarely, on Réunion . When sorediate, the thalli have short and generally unbranched laciniae. The formation of soralia is variable from one specimen to another, even from one lobe to another in the same thallus. Granulose soredia may appear at the tip of marginal teeth or short laciniae, within more-or-less erumpent and orbicular submarginal soralia, or occasionally by disintegration of short laminal isidioid outgrowths. This sorediate form of P. nephophilum could be confused with P . bangii (Vain.) Hale , a similar sorediate species with the same stictic acid chemosyndrome. However, P. bangii differs by its very fragile and flaking upper cortex, its sorediate pustules, and the complete absence of isidioid structures ( Hale 1965a , Krog & Swinscow 1981 , Sérusiaux 1984 , Spielmann & Marcelli 2009 ). When compared with the sorediate form of P. nephophilum , P. perlatum shares the same chemistry and is also sorediate, but its soralia are more conspicuous and are usually located at the tips of revolute lobes, its soredia are less granular, and the lower marginal surface of its sorediate lobes is never white or mottled with white (except under lobes also bearing apothecia). Furthermore, phylogenetic analyses show that the two taxa are clearly distinct ( Fig. 3 & 4 ). Apart from the vegetative propagules, the morphology and anatomy of both forms of P. nephophilum are similar, including the shape and size of the conidia, as well as the chemistry. Moreover, both forms were recovered intermixed in a single, well-supported clade in the phylogenetic trees ( Fig. 3 & 4 ), and both species discovery methods here used (bPP and Stacey) failed to separate them ( Fig. 3 ). Based on our current state of knowledge, the sorediate form seems to have a more restricted distribution ( Fig. 29B ) than the isidiate/phyllidiate form ( Fig. 29A ); it has only been found at nine localities (versus 45 localities). At two of them, both forms were found side by side on the same substrate. The elevations and bioclimates of the localities frequented by the two forms are similar, except for the ombrotypes. The sorediate form was found on average in less humid locations (mean Io = 10.6) than those inhabited by the isidiate/ phyllidiate form (mean Io = 16.5) (Wilcoxon-Mann-Whitney test, P = 0.012, one-tailed). All these observations led us to consider these two main forms as morphotypes of a single species that is highly polymorphic in the production of vegetative propagules. The phylogenetic relationships of P. nephophilum are unclear but it was resolved in a supported clade in the 3- locus tree ( Fig. 3 ) comprising our accessions of P. crinitum , P. occultum and P. perlatum , three species which share the same medullary chemistry with P. nephophilum (stictic acid chemosyndrome). The same supported clade appears in the ITS tree ( Fig. 4 ), including P. internexum , whose medulla also contains the stictic acid chemosyndrome along with norlobaridone (Lendemer 2015). Additional specimens examined ( paratypes ): Isidiate/phyllidiate morphotype :— FRANCE . Réunion : without locality, 1840, M.E. Mézières de Lépervanche 38 (PC 0009288 b & c); Cilaos, Ravine des Calumets, elev. 1140 m , 21°09’34”S , 55°29’26”E , disturbed wooded ravine, in an overall south orientation, on a 75° inclined and NE oriented face of a ± mossy basalt rock, 21 August 2012 , D. Masson 974.3953 (Hb. DM); ibid ., elev. 1205 m , 21°09’19”S , 55°29’31”E , in disturbed leeward montane rainforest, in a ravine in an overall SSW orientation, on the bark of twigs of an undetermined shrub, 21 August 2012 , D. Masson 974.3945 (Hb. DM); ibid ., la Mare à Monfleury, elev. 1410 m , 21°08’57”S , 55°29’38”E , in disturbed leeward montane rainforest, in an overall NNW orientation, on a 55° inclined and NE oriented face of a mossy small basalt rock, 21 August 2012 , D. Masson 974.3935 (LG); ibid ., south edge of Forêt du Grand Matarum, elev. 1360 m , 21°07.4’S , 55°28.9’E , picnic place, big boulders and outcrops along stream, on outcrop, 31 May 2008 , P. & B. van den Boom 40214 ( Hb. van den Boom); Entre-Deux, sentier de la Grande Jument , elev. 1115 m , 21°12’46”S , 55°28’59”E , in leeward montane rainforest, in an overall south orientation, on old bark and wood of a trunk of an undetermined dead tree, 16 August 2015 , D. Masson 974.4664 (Hb. DM); ibid ., elev. 1200 m , 21°12’31”S , 55°28’59”E , in leeward montane rainforest, in an overall west orientation, on bark of a branch of a young Dombeya sp. , 16 August 2015 , D. Masson 974.4675 (Hb. DM); La Plaine-de-Palmistes, col de Bellevue, elev. 1600 m , 21°09’55”S , 55°35’25”E , in windward montane rainforest, on bark of a trunk of Dombeya ficulnea , 18 July 2005 , D. Masson 974.1473 (Hb. DM); ibid ., sentier du Piton des Cabris, elev. 1690 m , 21°09’26”S , 55°39’04”E , in windward montane rainforest, on mossy bark of a trunk of an undetermined young tree, 21 August 2013 , D. Masson 974.4348 (Hb. DM); ibid ., along road to forêt de Bébour, Cryptomeria forest with ‘Sentier botanique’, elev. 1220 m , 21°08.50’S , 55°35.20’E , path in small rainforest and outcrops near stream, on unidentified tree, 30 cm diam., 26 May 2008 , P. & B. van den Boom 39744 ( Hb. van den Boom); La Possession, Roche Verre Bouteille, elev. 1300 m , 20°59’16”S , 55°23’36”E , in montane Erica thicket, on a volcanic rock, 04 August 2005 , D. Masson 974.1935 (Hb. DM); La Possession, Dos d’Âne, sentier des Lataniers, elev. 1175 m , 20°58’34”S , 55°23’22”E , in leeward submontane rainforest on a steep south-facing slope, on bark of the trunk of an undetermined dead tree, 17 August 2012 , D. Masson 974.3862 (Hb. DM); ibid ., elev. 1145 m , 20°58’28”S , 55°23’35”E , scree largely overgrown by Lantana camara , in leeward submontane rainforest, on a 40° inclined and SE oriented face of a basalt boulder, 17 August 2012 , D. Masson 974.3859 (Hb. DM); ibid ., southern slope of Piton Grand Bazar, elev. 1210 m , 20°58’33”S , 55°23’23”E , in leeward montane rainforest, in an overall south orientation, on bark of the trunk of an undetermined tree, 19 August 2015 , D. Masson 974.4721 (Hb. DM); ibid ., La Grande Montagne , elev. 1330 m , 20°58’19”S , 55°23’30”E , in leeward montane rainforest, in an overall NW orientation, on mossy bark of the trunk of Dombeya sp. , 19August 2015 , D. Masson 974.4730 (LG); ibid ., elev. 1330 m , 20°58’11”S , 55°23’40”E , in leeward montane rainforest, in an overall NW orientation, on bark of the trunk of Nuxia verticillata , 19 August 2015 , D. Masson 974.4735 (Hb. DM); ibid ., elev. 1350 m , 20°58’07”S , 55°23’45”E , in leeward montane rainforest, in an overall NW orientation, on bark of the branch of Nuxia verticillata , 19 August 2015 , D. Masson 974.4738 (Hb. DM); Le Tampon, forêt de Notre-Dame de la Paix, elev. 1700 m , 21°15’55”S , 55°36’06”E , in windward montane rainforest, on bark of undetermined trees, 17 July 2005 , D. Masson 974.1437 (REU), 974.1438 , 974.1439 (Hb. DM); ibid ., elev. 1715 m , 21°15’50”S , 55°36’05”E , in windward montane rainforest, on bark of trunk of Nuxia verticillata , 17 July 2005 , D. Masson 974.1378 (Hb. DM); ibid ., le Volcan, trail to Piton Textor, elev. 1805 m , 21°10’38”S , 55°38’09”E , in windward montane rainforest, on a NNW facing slope, on mossy bark of trunk of Aphloia theiformis , 27 August 2012 , D. Masson 974.4088 (LG); Petite-Île, Haut de la forêt communale, Piton la Mare, elev. 1530 m , 21°17’24”S , 55°35’55”E , in leeward montane rainforest, on trunk of dead Cyathea glauca , 17 August 2017 , D. Masson 974.4984 (Hb. DM); Saint-André, forêt de Dioré, elev. 765–770 m , 20°59’38”S , 55°35’34”E , in windward submontane rainforest, on bark of branch of Geniostoma borbonicum and trunks of undetermined trees, 28 July 2005 & 21 August 2017 , D. Masson 974.1806 (REU), 974.1811, 974.5048 (Hb. DM); Saint-Benoît, Piton de Bébour, elev. 1330 m , 21°07’45”S , 55°34’10”E , in windward montane rainforest, on bark of trunk of Dombeya sp. , 07 April 2003 , D. Masson 974.0038 (REU), 974.0039 (Hb. DM); ibid ., elev. 1345 m , 21°07’38”S , 55°33’59”E , in windward montane rainforest, on bark of branch of Nuxia verticillata , 07 April 2003 , D. Masson 974.0078 (Hb. DM); ibid ., elev. 1380– 85 m , 21°07’34”S , 55°33’54”E , in windward montane rainforest, on bark of trunk of Dombeya sp. and on trunk of a dead undetermined tree, 07 April 2003 , D. Masson 974.0122 (REU), 974.0142 (Hb. DM); ibid ., forêt de Bébour, plateau de Duvernay, elev. 1320 m , 21°07’27”S , 55°34’28”E , in windward montane rainforest, in an overall SE orientation, on bark of branch of Dombeya sp. , 21 August 2015 , D. Masson 974.4771 (LG); ibid ., forêt de Bébour, piste forestière de Takamaka, elev. 1335 m , 21°06’16”S , 55°34’11”E , in windward montane rainforest, on mossy bark of branch of Dombeya sp. , 16 August 2017 , D. Masson 974.4967 (Hb. DM); ibid ., forêt de Bébour, sentier de Takamaka, elev. 1360 m , 21°06’23”S , 55°33’58”E , in windward montane rainforest, on bark of branch of Claoxylon sp. , 29 July 2005 , D. Masson 974.1839 (Hb. DM); Saint-Denis, Plaine d’Affouches, elev. 1540 m , 20°59’04”S , 55°25’17”E , in leeward montane rainforest, on bark of a sub-horizontal branch of Sideroxylon borbonicum , 18 August 2012 , D. Masson 974.3866 (LG); Saint-Joseph, sentier du Piton du Rond, elev. 1115 m , 21°18’35”S , 55°36’04”E , in leeward submontane rainforest, in an overall SSW orientation, on bark of trunk of an undetermined tree, 18 August 2013 , D. Masson 974.4292 (Hb. DM); ibid ., elev. 1140 m , 21°18’32”S , 55°36’04”E , in leeward submontane rainforest, in an overall SW orientation, on ± mossy bark of trunk of Ficus sp. , 18 August 2013 , D. Masson 974.4293 (Hb. DM); ibid ., elev. 1300 m , 21°18’08”S , 55°36’08”E , in leeward montane rainforest, in an overall WSW orientation, on bark of branch of an undetermined dead tree, 18August 2013 , D. Masson 974.4300 (Hb. DM); ibid ., Grand Coude, elev. 1290 m , 21°16’42”S , 55°37’39”E , in disturbed windward montane rainforest, on bark of trunk of Dombeya sp. , 24 August 2017 , D. Masson 974.5109 (Hb. DM); ibid ., elev. 1340 m , 21°16’36”S , 55°37’44”E , in disturbed windward montane rainforest, on bark of trunk of Dombeya sp. , 24 August 2017 , D. Masson 974.5110 (LG); Saint-Louis, Les Makes, Bois Bon Accueil, elev. 1160 m , 21°11’36”S , 55°24’07”E , in leeward submontane rainforest, on bark of trunk of an undetermined tree, 28 August 2017 , D. Masson 974.5150 (Hb. DM); Saint-Philippe, forêt de Saint-Philippe, sentier de Piton Ravine Basse Vallée, elev. 780 m , 21°20’15”S , 55°42’24”E , in windward submontane rainforest, in an overall SW orientation, on ± mossy bark of trunk of an undetermined tree, 16 August 2013 , D. Masson 974.4249 (Hb. DM); ibid ., elev. 915 m , 21°19’52”S , 55°42’16”E , in windward submontane rainforest, in an overall SSW orientation, on ± mossy bark of a branch and trunk of Phyllanthus phillyreifolius , 16 August 2013 , D. Masson 974.4255 (REU), 974.4256 (Hb. DM); ibid ., elev. 1030 m , 21°19’34”S , 55°42’13”E , in Pandanus wet thicket, in an overall SSW orientation, on ± mossy bark of trunk of an undetermined dead tree, 16August 2013 , D. Masson 974.4266 (Hb. DM); ibid ., elev. 1100 m , 21°19’26”S , 55°42’17”E , in windward montane rainforest, in an overall SSW orientation, on bark of branches of Phyllanthus phillyreifolius , 16 August 2013 , D. Masson 974.4270 (Hb. DM), 974.4271 (LG); ibid ., route forestière des Camphriers, elev. 685 m , 21°20’28”S , 55°42’33”E , on the edge of a camphor tree plantation, on mossy bark of trunk of Cinnamomum camphora , 25 August 2017 , D. Masson 974.5124 (Hb. DM); Sainte-Marie, Plaine des Fougères, elev. 1440 m , 20°58’49”S , 55°30’08”E , in windward montane rainforest, in an overall NNE orientation, on ± mossy bark of trunk of an undetermined dead tree, 30 August 2012 , D. Masson 974.4137 (Hb. DM); ibid ., elev. 1235 m , 20°58’31”S , 55°31’01”E , in windward montane rainforest, on bark of branch of an undetermined tree, 17 April 2003 , D. Masson 974.0451 (Hb. DM); ibid ., between Ravine Sèche and Ravine Mère Canal, elev. 1250 m , 20°58’33”S , 55°30’59”E , in windward montane rainforest, in an overall NE orientation, on bark of trunk of a young Badula barthesia & on mossy bark of a branch of an undetermined tree, 30 August 2012 , D. Masson 974.4125 (REU), 974.4126 (Hb. DM); Sainte-Suzanne, les Hauts de la Perrière, ravine Bras Laurent, elev. 755 m , 20°58’49”S , 55°33’48”E , in disturbed windward submontane rainforest, on a NE-facing slope, on mossy bark of branch of an undetermined big tree, 11 August 2015 , D. Masson 974.4596 (Hb. DM); Salazie, Piton d’Enchain, elev. 1350 m , 21°02’39”S , 55°29’57”E , in windward montane rainforest, on bark of Claoxylon sp. , 13 April 2003 , D. Masson 974.0326 (Hb. DM); ibid ., Forêt de Bélouve, track from Gîte de Bélouve to viewpoint, elev. 1500 m , 21°03’39”S , 55°32’10”E , 30 September 1996 , H. Krog RE25/27 & E. Timdal (O). Sorediate morphotype :— FRANCE . Réunion : Cilaos , sentier du col du Taïbit , near source Ti Louis , elev. 1835 m , 21°06’46”S , 55°26’26”E , in leeward montane rainforest, in an overall east orientation, on bark of the trunk of Aphloia theiformis , 17 August 2015 , D. Masson 974.4709 ( LG ) ; ibid ., Aufstieg von Thermales Richtung Col du Taïbit , elev. 1300 m , 21°07’S , 55°28’E , sekundärer Niederwald , 22 August 1991 , K. & A. Kalb 32144 ( WIS ) ; ibid ., southern slope of Bonnet Carré, GR R1 trail, elev. 1380 m , 21°07’35”S , 55°28’06”E , in disturbed leeward montane rainforest, in an overall south orientation, on bark of the trunk of Nuxia verticillata , 18 August 2015 , D. Masson 974.4716 ( LG ) ; ibid ., Bras Sec , sentier Kervéguen , elev. 1500 m , 21°07’42”S , 55°29’55”E , in leeward montane rainforest, in an overall west orientation, on ± mossy bark of a horizontal branch of an undetermined dead tree, 22 August 2012 , D. Masson 974.3964 ( LG ) ; Entre-Deux , sentier de la Grande Jument , elev. 1115 m , 21°12’46”S , 55°28’59”E , in leeward montane rainforest, in an overall south orientation, on wood and old bark of trunk of an undetermined dead tree, 16 August 2015 , D. Masson 974.4663 ( Hb. DM ) ; ibid ., elev. 1200 m , 21°12’31”S , 55°28’59”E , in leeward montane rainforest, in an overall west orientation, on bark of branch of a young Dombeya sp. , 16 August 2015 , D. Masson 974.4676 ( Hb. DM) ; Saint-Joseph , Grand Coude , elev. 1195 m , 21°17’09”S , 55°37’31”E , cultivated area with pastures, on bark of branches of Hypericum lanceolatum , 24 August 2017 , D. Masson 974.5123 ( LG ) ; Saint-Louis , Les Makes , Bois Bon Accueil , elev. 1055 m , 21°11’51”S , 55°23’57”E , in leeward submontane rainforest, on bark of trunk of Weinmannia sp. , 28 August 2017 , D. Masson 974.5146 ( LG ) ; ibid ., elev. 1105 m , 21°11’44”S , 55°23’59”E , in leeward submontane rainforest, in an overall south orientation, on mossy bark of Phyllanthus phillyreifolius , 28 August 2017 , D. Masson 974.5147 ( LG ) . Specimen studied for comparison : Parmotrema eliasaroanum .— BRAZIL . São Paulo : Cananéia , Ilha do Cardoso , restinga da Vila Marujá , sobre ramo fino de arbusto, 20 October 1981 , M.P. Marcelli 1757 (B, isotype ) .