Parmotrema crinitum (Ach.) M. Choisy (1952: 175) MycoBank

Masson, Didier, Magain, Nicolas & Sérusiaux, Emmanuël, 2024, 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, Phytotaxa 657 (1), pp. 1-138 : 33-39

Parmotrema crinitum (Ach.) M. Choisy (1952: 175) MycoBank no. 368891

Parmelia crinita Ach. (1814: 196) MycoBank no. 119691

Type:— USA. Pennsylvania: [Lancaster County?], s.d., G.H.E. Muhlenberg s.n. (H [image!], lectotype; PH [image!], isolectotype; designated by Hale 1965 a, Lendemer & Hewitt 2002).

( Fig. 14 )

Morphological description, chemistry and ecology based on genetically analysed material from Réunion (ten specimens).

Thallus foliose, loosely to moderately adnate, membranaceous, rarely subcoriaceous, up to 10 × 14 cm. Lobes irregularly branched, imbricate, rarely contiguous, 2–9 mm wide, irregularly wrinkled; margins incised to laciniate, or lobulate, irregularly isidiate, ciliate ( Fig. 14D ). Cilia black, generally numerous and ± evenly distributed at the margin of the lobes, lobules and laciniae, rarely sparse, mostly simple, rarely 1–(2) times branched or slightly squarrose, up to 3 mm long. Upper surface pale greenish grey, dull, slightly shinier towards the periphery, faintly to clearly white-maculate, rugulose to ± rugose; often finely cracked, even in young parts; isidiate, lacking soralia, schizidia, pustules, dactyls. Isidia moderately dense to dense, marginal and laminal, but often tend to concentrate submarginally, granular to coralloid, very occasionally irregularly flattened and then looking like phyllidia; often apically and/or laterally ciliate; up to 5 mm high ( Fig. 14E ). Laciniae occasional, marginal, sparse, unbranched to slightly branched, up to 1.5 mm long, 0.2–1 mm wide, ciliate, at times isidiate. Lobules occasional, marginal, up to 2 × 3 mm, ciliate, ± isidiate. Medulla white throughout. Lower surface rugulose or granulate, ± shiny, black to the margin, or with a chestnut brown, erhizinate or partly rhizinate, marginal zone (ca. 0.5–4 mm wide) at main lobe tips, lateral lobes with isidia or apothecia often with an erhizinate or rhizinate, ivory white or ivory-mottled, marginal zone (0.2–2 mm wide). Rhizines numerous, ± evenly distributed, black, slender, simple, rarely 1–2 times branched or squarrose, up to 3 mm long. Apothecia present in two specimens out of ten, submarginal, up to 8 mm in diameter, stipitate on constricted stipes, disc non perforate; margin ± crenate, early with eciliate or ciliate isidia, which extend on the amphithecium and stipe with age ( Fig. 14F ); hymenium s. lat. (74)– 102.2 –(130) µm high, proper exciple with hyaline layer (2)– 4.0 –(7) µm high, intermediate layer (6)– 8.4 –(13) µm high, cortex-like basal layer (11)– 21.8 –(37) µm high. Ascospores (18.5)– 26.6 – (33.5) × (10.5)– 15.4 –(21) µm, Q =(1.42)– 1.73 –(2.06,) epispore (2.5)– 3.4 –(4.5) µm thick, n = 60, from two specimens, mean values for each specimen: 22.5 × 13.8, 30.8 × 17.1 µm. Pycnidia rare, submarginal on lobes, but also on isidia, black. Conidia bacilliform 5–6 × ca. 1 µm.

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 (minor), cryptostictic acid (trace) and hypostictic acid (trace).

Geographical distribution:—This taxon is usually considered cosmopolitan (e.g. Du Rietz 1924, Hale 1965a, Louwhoff 2001), and occurring in numerous tropical, temperate, and even sub-boreal and sub-Antarctic regions ( Øvstedal & Gremmen 2008, Michlig & Ferraro 2010, Elix & Thell 2011). In the MIOI hotspot, it has been reported from Madagascar ( des Abbayes 1961), Mauritius (Diederich & Ertz 2020) and Réunion ( Hue 1899, des Abbayes 1961, van den Boom et al. 2011). According to the DNA data obtained from material collected on Réunion, P. crinitum s. str. seems to be widespread in the uplands of the island ( Fig. 14A ). These specimens were collected between 1080 and 2075 m elevation. If we consider (see Notes below) that most of the collections of Parmotrema from Réunion showing the crinitum phenotype and whose DNA has not been studied (= P. cf. crinitum ) actually belong to P. crinitum s. str., then this taxon is the most frequently collected species of Parmotrema on the island (found in possibly up to 60 UTM 1× 1 km grid cells, or 48 UTM 2× 2 km grid cells, Fig. 14A & 14B ).

Ecology:—Molecularly analysed specimens were all epiphytic. They grew on mosses (developing on bark or volcanic rock), on stipe of a tree fern ( Cyathea ), and on bark of trunks and branches of various native trees and shrubs belonging to the genera Aphloia , Dombeya , Hypericum , Pandanus , and Stoebe . They were collected in cloud forests (montane rainforest, Acacia montane forest, Erica montane thicket), but also in submontane rainforest, subalpine Sophora thicket, as well as in a cultivated area with pastures. Bioclimatic features of the localities are also diverse ( Fig. 14C ): bioclimate pluvial tropical, thermotype belts from upper thermotropical to upper mesotropical (325 ≤ It ≤ 532), ombrotype belts from lower humid to ultrahyperhumid (7.1 ≤ Io ≤ 27.8). The ecological niche of Parmotrema crinitum on Réunion seems therefore rather wide: if there is sufficient humidity in the atmosphere or on the substrate, the species is present. This is consistent with reports from other parts of the world (e.g. Tavares 1945, Schauer 1965, Dey 1978, Lai 2001, Lendemer 2015).

Notes:— Parmotrema crinitum is a species typically characterized by ciliate lobe margins, commonly ciliate isidia, black lower surface, and unpigmented medulla with stictic and constictic acids as main extrolites ( Poelt & Vezda 1977, Swinscow & Krog 1988, Elix 1994, Brodo et al. 2001, Divakar & Upreti 2005). However, our molecular investigations show that these morphological and chemical characters are shared, at least on Réunion, by two sibling taxa ( Fig. 3 & 4 ). Ten out of twelve thalli for which ITS is available are nested into the same clade as the specimens from Europe and the USA. As the type collection of P. crinitum comes from Pennsylvania, USA, we attribute these ten specimens to this species. The two remaining thalli form a well-supported monophyletic group, which we describe as a new species, P. occultum (see below the entry taxon). If the average thickness of the cupular exciple is indeed a diagnostic character allowing to discriminate these two phenotypically very similar taxa, then all the ascospore-producing thalli collected, but not molecularly analysed, belong to P. crinitum ( Fig. 15A ). The measurements of the ascospores produced by these thalli strongly suggest the existence of large intraspecific variability in the populations of P. crinitum from Réunion ( Fig. 15B ).

There is little information in the literature on the morphology and size of the conidia produced by P. crinitum . Hale (1965a) cited a length of 3–4 µm, ‘after Asahina’. Unfortunately, we failed to find any trace of this data in Asahina publications (1952a, b) dealing with this lichen. Elix (1994) reported sublageniform conidia, with the same dimensions 3–4 × 1 µm. Our data from Réunion are not consistent with those published so far: we observed conidia different in shape (bacilliform vs sublageniform) and longer (5–6 vs 3–4 µm). On the other hand, the conidia of P. crinitum from Réunion share similar characteristics with those of P. perlatum , a closely related, or even conspecific, taxon ( Stelate et al. 2022), as well as with the related P. occultum , P. internexum (Nyl.) Hale ex DePriest & B.W. Hale , and P. nephophilum D.M. Masson & Sérus. sp. nov. ( Fig. 3 , Table 6). Further data from Australia and Asia are needed, especially molecular data, to clarify this apparent divergence in the morphology of the conidia of P. crinitum .

present work.

In our 3-locus analysis ( Fig. 3 ), three accessions of P. crinitum (including one from continental France) were resolved in a single clade, and were recovered as sister to an accession of P. perlatum (from continental France). However, Stacey and bPP analyses merge the four specimens into a single species. Whether the sorediate taxon ( P. perlatum ) is conspecific with the isidiate taxon ( P. crinitum ) is still a matter of debate ( Stelate et al. 2022).

Specimens with molecular data examined:— FRANCE. Réunion: Cilaos, above Îlet des Salazes, elev. 1740 m, 21°06’31”S, 55°26’48”E, in leeward montane rainforest, in an overall south orientation, on bark of a trunk of Hypericum lanceolatum , 20 August 2012, D. Masson 974.3927 (LG); Entre-Deux, sentier de la Grande Jument , elev. 1115 m, 21°12’47”S, 55°28’58”E, in leeward montane rainforest, in an overall south orientation, on a mossy and shady volcanic rock, 16 August 2015, D. Masson 974.4662 (LG); La Possession, la Grande Montagne , sentier des Lataniers, elev. 1330 m, 20°58’21”S, 55°23’31”E, in leeward montane rainforest, in an overall NW orientation, on bark of a branch of Pandanus sp. , 19 August 2015, D. Masson 974.4725 (LG); ibid., Piton Marmite, elev. 1800 m, 21°03’31”S, 55°27’09”E, in Erica montane thicket, in an overall NW orientation, on mossy bark of Erica reunionensis , 23 August 2017, D. Masson 974.5107 (LG); Le Tampon, sentier du Piton Textor, elev. 2075 m, 21°10’59”S, 55°38’24”E, in subalpine Sophora thicket, in an overall NW orientation, on mossy bark of a trunk of Sophora denudata , 27 August 2012, D. Masson 974.4081 (LG); L’Étang-Salé, Chemin Canal, elev. 1080 m, 21°12’40”S, 55°22’36”E, in leeward submontane rainforest, in an overall west orientation, on bark of a dead branch of Dombeya sp. , 27 August 2017, D. Masson 974.5143 (LG); Petite-Île, Haut de la forêt communale, Piton la Mare, elev. 1530 m, 21°17’31”S, 55°35’55”E, in leeward montane rainforest, on bark of a branch of Aphloia theiformis , 17 August 2017, D. Masson 974.4981 (LG); Saint-Benoît, forêt de Bébour, les Trois Mares, elev. 1405 m, 21°06’19”S, 55°33’30”E, in Erica montane thicket, in an overall east orientation, on bark of a branch of Stoebe passerinoides , 21 August 2015, D. Masson 974.4777 (LG); Saint-Denis, Plaine d’Affouches, elev. 1710 m, 20°59’15”S, 55°25’58”E, in Acacia montane forest, at the base of a stipe of Cyathea sp. , 18 August 2012, D. Masson 974.3889 (LG); Saint-Joseph, Grand Coude, elev. 1195 m, 21°17’09”S, 55°37’31”E, cultivated area with pastures, on bark of branche of Hypericum lanceolatum , 24 August 2017, D. Masson 974.5122 (LG).

Specimens without molecular data but with mature apothecia examined:— FRANCE. Réunion: Cilaos, sentier du col du Taïbit, Plaine des Fraises, elev. 1925 m, 21°06’49”S, 55°26’17”E, in leeward montane rainforest, in an overall SW orientation, on mossy bark of the trunk of an old Hypericum lanceolatum , 17 August 2015, D. Masson 974.4706 (Hb. DM); ibid., above Îlet des Salazes, elev. 1805 m, 21°06’26”S, 55°26’56”E, in leeward montane rainforest, in an overall south orientation, on mossy basalt rock, 20 August 2012, D. Masson 974.3932 (Hb. DM); Le Tampon, Notre-Dame de la Paix, elev. 1630 m, 21°16’18”S, 55°36’01”E, edge of track in leeward montane rainforest, on bark of a branch of Hypericum lanceolatum , 17 August 2017, D. Masson 974.4973 (Hb. DM); Petite-Île, Haut de la forêt communale, Piton la Mare, elev. 1505 m, 21°17’35”S, 55°35’55”E, in leeward montane rainforest, on mossy bark of a trunk of Phyllanthus phillyreifolius , 17 August 2017, D. Masson 974.4982 (Hb. DM); Saint-Benoît, forêt de Bébour, Coteau des Calumets, elev. 1520 m, 21°05’48”S, 55°33’03”E, in windward montane rainforest, on bark of branch of Dombeya sp. , 16 August 2017, D. Masson 974.4971, 974.4972 (Hb. DM); ibid., Piton de Bébour, elev. 1390 m, 21°07’33”S, 55°33’52”E, in windward montane rainforest, on bark of branches of Monimia rotundifolia and undetermined trees, 07 April 2003, D. Masson 974.0023 (Hb. DM); Salazie, Bélouve, Pic des Chèvres, elev. 1780 m, 21°04’46”S, 55°31’39”E, in Erica montane thicket, in an overall NE orientation, on bark of a trunk of Weinmannia sp. , 25 August 2013, D. Masson 974.4477 (Hb. DM).

Specimens without molecular data nor mature apothecia examined ( P. cf. crinitum ):— FRANCE. Réunion: Cilaos, Bras Sec, la Mare à Montfleury, elev. 1390 m, 21°08’50”S, 55°29’35”E, in disturbed leeward montane rainforest, in an overall NW orientation, on bark of a trunk of Weinmannia sp. , 21 August 2012, D. Masson 974.3933 (Hb. DM); ibid., Bras Sec, sentier Kervéguen, elev. 1435 m, 21°07’45”S, 55°29’53”E, on the edge of a leeward montane rainforest and a Cryptomeria japonica plantation, in an overall west orientation, on a 60° inclined and south oriented face of a big basalt rock, 22 August 2012, D. Masson 974.3980 (REU), 974.3981 (Hb. DM); ibid., sentier du col du Taïbit, Plaine des Fraises, elev. 1930 m, 21°06’50”S, 55°26’21”E, thicket of old Erica in leeward montane rainforest, in an overall south orientation, on bark of Erica reunionensis , 17 August 2015, D. Masson 974.4703 (Hb. DM); ibid., above Îlet des Salazes, elev. 1710 m, 21°06’47”S, 55°26’42”E, in disturbed leeward montane rainforest, in an overall SE orientation, on mosses on a subvertical and SSE oriented face of a large volcanic breccia rock, 20 August 2012, D. Masson 974.3899 (Hb. DM); ibid., elev. 1730 m, 21°06’33”S, 55°26’47”E, in leeward montane rainforest, in an overall SE orientation, on ± mossy bark of Hubertia sp. , 20 August 2012, D. Masson 974.3918, 974.3925 (Hb. DM); ibid., elev. 1775 m, 21°06’29”S, 55°26’54”E, in leeward montane rainforest, in an overall south orientation, on mossy basalt rock, 20 August 2012, D. Masson 974.3929 (Hb. DM); Entre-Deux, crête du Dimitile, elev. 1850–2000 m, montane heath with Erica , Stoebe , Hypericum ; on trunk of Nuxia in shade, 04 August 1994, D.H. Lorence 7556a, A Rolland & A. Coret (O); La Plaine-des-Palmistes, col de Bébour, along track towards Plaine des Cafres, elev. 1420 m, 21°07’54”S, 55°34’31”E, 04 October 1996, H. Krog RE40/31 & E. Timdal (O); ibid., col de Bellevue, elev. 1600 m, 21°09’55”S, 55°35’25”E, in disturbed windward montane rainforest, on mossy bark of a branch of Dombeya sp. , 18 July 2005, D. Masson 974.1472 (Hb. DM); ibid., Piton des Cabris, elev. 1620 m, 21°09’20”S, 55°39’02”E, in windward montane rainforest, in an overall north orientation, on mossy bark of a branch of Dombeya sp. , 21 August 2013, D. Masson 974.4346 (Hb. DM); ibid., elev. 1690–1700 m, 21°09’27”S, 55°39’05”E, in windward montane rainforest, on mossy bark of branch and trunk of Dombeya sp. , 21 August 2013, D. Masson 974.4349, 974.4350 (Hb. DM); ibid., elev. 1710 m, 21°09’31”S, 55°39’13”E, in windward montane rainforest, on mossy bark of branches of Dombeya sp. , 21 August 2013, D. Masson 974.4363 (REU), 974.4364, 974.4365 (Hb. DM); La Possession, la Grande montagne , sentier des Lataniers, elev. 1320 m, 20°58’11”S, 55°23’37”E, in leeward montane rainforest, in an overall NW orientation, on bark of a branch of Dombeya sp. , 19 August 2015, D. Masson 974.4734 (Hb. DM); ibid., cirque de Mafate, Plaine des Tamarins, elev. 1765 m, 21°04’58”S, 55°26’19”E, in grazed Acacia montane forest, on mossy bark of a branch of Acacia heterophylla , 22 August 2017, D. Masson 974.5081 (Hb. DM); ibid., Piton Marmite, elev. 1830 m, 21°03’32”S, 55°27’12”E, in Erica montane thicket, in an overall NW orientation, on mossy bark of twigs of Melicope obscura , 23 August 2017, D. Masson 974.5106 (Hb. DM); Les Avirons, route forestière 6 du Tévelave, elev. 1660 m, 21°10’46”S, 55°22’46”E, in Acacia montane forest, on bark of a trunk of Acacia heterophylla , 10 April 2003, D. Masson 974.0284 (Hb. DM); Le Tampon, forêt de Notre-Dame de la Paix, sentier botanique, elev. 1700 m, 21°15’57”S, 55°36’07”E, in leeward montane rainforest, on bark of undetermined trees, 17 July 2005, D. Masson 974.1436, 974.1441 (Hb. DM); ibid., le Belvédère, elev. 1715– 20 m, 21°15’49”S, 55°36’07”E, in leeward montane rainforest, on bark of undetermined trees, 17 July 2005, D. Masson 974.1377 (REU), 974.1414 (Hb. DM); ibid., trail at south rim, from picnic place up to 200 m inside the forest, elev. 1720 m, rainforest, 06 June 2008, P. & B. van den Boom 40776 ( Hb. van den Boom); ibid., Nez de Boeuf, elev. 2120 m, in subalpine Sophora thicket, corticolous, 28 September 1956, H. des Abbayes 2969 (REN); ibid., elev. 2000 m, highland vegetation, on Sophora denudata , June 1957, J. Bosser 11.245 (REN); ibid., elev. 2035 m, 21°12’17”S, 55°37’19”E, in disturbed subalpine Sophora thicket, on bark of a branch of Hypericum lanceolatum , 20 August 2017, D. Masson 974.5036 (Hb. DM); ibid., elev. 2040 m, 21°12’37”S, 55°36’53”E, in subalpine Sophora thicket, on mossy bark of Sophora denudata , 19 July 2005, D. Masson 974.1573 (Hb. DM); ibid., between Nez de Boeuf and Piton Textor, elev. 2090 m, 21°11.6’S, 55°37.5’E, picnic place with Sophora denudata trees, on Sophora denudata , 04 June 2008, P. & B. van den Boom 40679 ( Hb. van den Boom); ibid., sentier du Piton des Tangues, elev. 2160 m, 21°11’32”S, 55°38’51”E, small Acacia wood in subalpine shrubland, in an overall NNE orientation, on bark of a branch of an old Acacia heterophylla , 22 August 2013, D. Masson 974.4390 (Hb. DM); ibid., rempart des Basaltes, elev. 2410 m, 21°12’38”S, 55°39’17”E, small Sophora thicket in subalpine shrubland, on bark of a branch of Sophora denudata , 22 August 2015, D. Masson 974.4794 (Hb. DM); ibid., Plaine des Cafres, Piton Desforges, elev. ca 1700 m, on trunk and branches of an old Monimia rotundifolia , 29 September 1956, H. des Abbayes 2981 (REN); ibid., forêt de la Plaine des Cafres, GR R2 trail, NW of Piton Tortue, elev. 1905 m, 21°08’25”S, 55°32’23”E, in Erica montane thicket, in an overall SE orientation, on ± mossy bark of a branch of Erica reunionensis , 23 August 2013, D. Masson 974.4428 (Hb. DM); ibid., Piton Grand-Mère, elev. 1640 m, 21°10’45”S, 55°35’17”E, in Erica montane thicket, on ± mossy bark of Erica reunionensis , 19 August 2017, D. Masson 974.5030, 974.5031 (Hb. DM); L’Étang-Salé, Chemin Canal, elev. 1075 m, 21°12’43”S, 55°22’36”E, in leeward submontane rainforest, on bark of Erica reunionensis , 27 August 2017, D. Masson 974.5140 (Hb. DM); Petite-Île, Haut de la forêt communale, Piton la Mare, elev. 1525 m, 21°17’23”S, 55°35’52”E, in leeward montane rainforest, on stipe of a dead Cyathea glauca , 17 August 2017, D. Masson 974.4985 (Hb. DM); ibid., elev. 1530 m, 21°17’29”S, 55°35’59”E, in leeward montane rainforest, on mossy bark of a branch of Dombeya sp. , 17 August 2017, D. Masson 974.4980 (Hb. DM); Saint-Benoît, forêt de Bébour, sentier des Tamarins, elev. 1550 m, 21°04’46”S, 55°32’38”E, in windward montane rainforest, on bark of a trunk of Monimia sp. , 19 July 2005, D. Masson 974.1540 (Hb. DM); ibid., elev. 1555 m, 21°04’54”S, 55°32’38”E, in windward montane rainforest, on bark of Hypericum lanceolatum , 19 July 2005, D. Masson 974.1548 (Hb. DM); ibid., Takamaka forest track, elev. 1360 m, 21°06’40”S, 55°33’56”E, in windward montane rainforest, on the stem of an old Solanum mauritianum , 16 August 2017, D. Masson 974.4970 (Hb. DM); ibid., sentier du Bassin des Hirondelles, elev. 1260 m, 21°07’05”S, 55°34’47”E, in windward montane rainforest, on mossy bark of an undetermined tree, 22 July 2005, D. Masson 974.1632 (Hb. DM); ibid., Piton de Bébour, elev. 1330 m, 21°07’45”S, 55°34’10”E, in windward montane rainforest, on bark of a trunk of Dombeya sp. , 07 April 2003, D. Masson 974.0036 (Hb. DM); ibid., elev. 1385– 90 m, 21°07’33”S, 55°33’52”E, in windward montane rainforest, on bark of branches of Monimia rotundifolia and undetermined trees, 07 April 2003, D. Masson 974.0027, 974.0128 (Hb. DM); ibid., elev. 1355 m, 21°07’35”S, 55°33’57”E, in windward montane rainforest, on bark of a branch of Dombeya sp. , 07 April 2003, D. Masson 974.0091 (Hb. DM); Saint-Denis, along road towards Plaine d’Affouches, near the kiosque, elev. 1230 m, 20°57’38”S, 55°25’00”E, 26 September 1996, H. Krog RE07/15 & E. Timdal (O); Saint-Joseph, sentier de la Rivière des Remparts, le Petit Mapou, elev. 1820 m, 21°11’53”S, 55°37’57”E, in windward montane rainforest, in an overall SSE orientation, on a mossy volcanic rock, 24 August 2015, D. Masson 974.4841 (Hb. DM); Saint-Louis, Les Makes, Bois Bon Accueil, elev. 1185 m, 21°11’30”S, 55°23’56”E, in leeward montane rainforest, in an overall south orientation, on bark of a branch of Dombeya sp. , 28 August 2017, D. Masson 974.5157 (Hb. DM); ibid., Plateau Goyaves, elev. 1710 m, 21°10’58”S, 55°24’33”E, in Cryptomeria japonica and Acacia heterophylla plantation, in an overall south orientation, on ± mossy bark of the trunk of a young Acacia heterophylla , 19 August 2013, D. Masson 974.4315 (Hb. DM); Saint-Paul, route forestière des Tamarins des Hauts-sous-le-Vent, elev. 1710 m, 21°05’26”S, 55°21’32”E, in grazed Acacia montane forest, on Solanum auriculatum , 10 April 2003, D. Masson 974.0265 (Hb. DM); ibid., elev. 1740 m, 21°04’18”S, 55°21’42”E, in grazed Acacia montane forest, on bark of Acacia heterophylla , 10 April 2003, D. Masson 974.0252, 974.0254 (Hb. DM); ibid., ravine la Source, elev. 1700 m, 21°04’39”S, 55°21’36”E, in Acacia montane forest, on bark of Dombeya sp. , 02 August 2005, D. Masson 974.1923 (Hb. DM); ibid., sentier Oméga, elev. 1600 m, 21°01’44”S, 55°22’39”E, in leeward montane rainforest, on bark of a trunk of Aphloia theiformis , 31 July 2005, D. Masson 974.1873 (Hb. DM); ibid., Le Maïdo, elev. 2180 m, 21°04’18”S, 55°23’14”E, in subalpine shrubland, on bark of a stunted Acacia heterophylla , 10 April 2003, D. Masson 974.0227, 974.0228 (Hb. DM); Saint-Pierre, forêt du Haut de Mont Vert, La Mare, elev. 1580 m, 21°17’10”S, 55°36’08”E, disturbed area with former grassland and leeward montane rainforest remnants, on bark of a branch of Hypericum lanceolatum , 17 August 2017, D. Masson 974.4978 (Hb. DM); ibid., Camp Mussard, elev. 1625 m, 21°16’44”S, 55°36’12”E, trackside in leeward montane rainforest, on bark of a trunk of Dombeya sp. , 17 August 2017, D. Masson 974.4976 (Hb. DM); Sainte-Marie, Plaine des Fougères, elev. 1635 m, 20°59’59”S, 55°30’25”E, in Acacia montane forest, in an overall NE orientation, on ± mossy bark of the trunk of a young Acacia heterophylla , 31 August 2012, D. Masson 974.4145 (Hb. DM); ibid., near Ravine Grand Bras Sec, elev. 1430 m, 20°59’14”S, 55°30’43”E, in windward montane rainforest, in an overall NE orientation, on bark of a branch of Monimia rotundifolia , 31 August 2012, D. Masson 974.4141 (Hb. DM); Sainte-Rose, Rampe Liot, elev. 2015 m, 21°12’48”S, 55°41’03”E, in grazed Acacia montane forest, in an overall NNW orientation, on mossy bark of a trunk of Acacia heterophylla , 25 August 2012, D. Masson 974.4024 (Hb. DM); ibid., fond de la Rivière de l’Est, elev. 1860 m, 21°12’33”S, 55°41’21”E, in grazed Acacia montane forest, on bark of the trunk of a dead undetermined tree, 20 July 2005, D. Masson 974.1618 (Hb. DM); Salazie, Mare d’Affouches, elev. 970 m, 21°02’44”S, 55°29’42”E, in disturbed windward submontane rainforest, on mossy bark of Aphloia theiformis , 13 April 2003, D. Masson 974.0297 (Hb. DM); ibid., forêt de Bélouve, track from gîte de Bélouve to viewpoint, elev. 1500 m, 30 September 1996, H. Krog RE25/28 & E. Timdal (O); ibid., sentier de l’École Normale, elev. 1565 m, 21°04’34”S, 55°32’35”E, in disturbed windward montane rainforest, on mossy bark of trunks of Acacia heterophylla and Claoxylon sp. , 24 August 2012, D. Masson 974.3997, 974.4022, 974.4023 (Hb. DM); ibid., elev. 1520 m, 21°04’19”S, 55°32’55”E, in disturbed windward montane rainforest, on ± mossy bark of branches of Claoxylon sp. , 24 August 2012, D. Masson 974.3999–4001 (Hb. DM).

Non-Reunionese specimen with molecular data studied for comparison:— FRANCE. Landes : Escource, Laurence, elev. 40 m, 44°10’31”N, 01°04’36”W, in Atlantic oak forest, on mossy bark of a trunk of Quercus robur , 20 January 2013, D. Masson 40.4184 ( LG) .

Figures

FIGURE 3. Phylogeny of the Parmotrema species studied. Best ML tree resulted from a RaxML analysis of three loci (EF1-α, ITS, mtSSU) and 102 specimens. Punctelia toxodes was selected as the outgroup. Bootstrap values are represented above the branches, and thick branches have bootstrap support value ≥ 70. Results of the species delimitation analyses are summarized to the right of the terminal labels of the tree. The first column corresponds to the results of the Stacey analysis, while the second column corresponds to the results of the bPP analysis. Specimens attributed the same colour were reconstructed as part of the same putative species by the species delimitation analysis. Major medullary extrolites are also shown for each specimen.

FIGURE 4. Global tree (best scoring maximum likelihood tree) of Parmotrema based on the fungal ITS barcoding marker. Figure can be enlarged for a better reading of labels. Accessions in black are those retrieved from GenBank on June 2023. Those in red are those produced by the authors for this study. Bootstrap support is indicated on branch when ≥ 70%.

FIGURE 14. Parmotrema crinitum. A: P. crinitum s. str.: distribution on Réunion (UTM 2×2 km grid system), lemon-yellow cells = specimens with molecular data, pale yellow cells with a cross = specimens without molecular data but with mature apothecia; B: P. cf. crinitum: distribution on Réunion (UTM 2×2 km grid system), specimens without apothecia and molecular data; C: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18), hatched: P. crinitum s. str., dotted: only P. cf. crinitum; D: Gross morphology of thallus (Masson 974.3889); E: Isidiate lobes with coralloid and ciliate isidia (Masson 974.3889); F: Apothecia with ciliate isidia on margin and amphithecium (Masson 974.4477). Scale bars:A, B = 10 km; D = 10 mm; E = 4 mm; F = 4 mm.

FIGURE 15. A: Comparison of the average thickness (± SE) of the cupular exciple of mature apothecia of 10 specimens of P. crinitum and one specimen of P. occultum. Means and standard errors were calculated from 5–12 measurements taken on a mature apothecium from each specimen of P. crinitum, and on two different mature apothecia from the same thallus of P. occultum (Masson 974.4966); B: Scatter plot of mean ascospore width versus mean ascospore length for 10 specimens of P. crinitum, two of which were also genetically analysed. For each sample, 30 randomly selected ascospores from a single well-developed apothecium were measured.