Parmotrema

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 : 118-121

Identification key to the Parmotrema species of Réunion Island

1. Medulla P− or P+ faint yellow ......................................................................................................................................................... 2

- Medulla P+ orange ......................................................................................................................................................................... 18

2. Medulla K−, C−, KC− ...................................................................................................................................................................... 3

- At least one of these 3 tests positive ................................................................................................................................................. 5

3. Without vegetative propagules .......................................................................................................................... [ P. appendiculatum ] (lobe margins and apothecia with corniculate laciniae, apothecial disc imperforate, medulla pigmented yellow near apothecia and containing barbatic acid and secalonic acid A; very rare species not recovered on Réunion since the 19 th century)

- With vegetative propagules .............................................................................................................................................................. 4

4. Thallus sorediate, lobes without cilia ................................................................................................................... P. praesorediosum (upper surface emaculate, soralia linear marginal when young, becoming labriform and crescent-shaped [ Fig. 34D ], medulla with fatty acids other than protolichesterinic acid; uncommon species on Réunion, at low elevations)

- Thallus isidiate and/or laciniate, cilia numerous ............................................................................................................. P. intonsum (shaggy appearance [ Fig. 21E ], upper surface ± distinctly punctiform white-maculate, esorediate, medulla with protolichesterinic acid as major substance; rather common in Reunionese cloud forests)

5. Medulla K+ yellow, C−, KC− (atranorin, fatty acids) .......................................................................................... P. praesorediosum (chemotype with atranorin, in addition to fatty acids, in the medulla)

- Other medullary reactions ................................................................................................................................................................ 6

6. Medulla K+ slowly pinkish brick red, C−, KC+ fleeting violet then brick red (lividic acid chemosyndrome) ......... P. reunionicum (lobe margins with conspicuous cilia, upper surface emaculate or faintly punctiform white-maculate, soralia mainly marginal and forming ± rounded clusters with age [ Fig. 36C ]; rare species, only known from a single locality)

- Medulla K−, C+ and/or KC+ pink, red, orange, or purple (lividic acid chemosyndrome absent) ................................................... 7

7. Medulla C+ and KC+ pink, red or orange ........................................................................................................................................ 8

- Medulla C−, KC+ purple, pinkish or orange .................................................................................................................................. 12

8. Medulla C+ and KC+ orange .............................................................................................................................. P. aurantioreagens (lobe margins ciliate, upper surface faintly to clearly effigurate white-maculate, soralia marginal at the tip of short laciniae [ Fig. 7D ], medulla with barbatic and 4- O -demethylbarbatic acids as major substances; rare species, only known from a single locality)

- Medulla C+ and KC+ pink or red ..................................................................................................................................................... 9

9. Thallus sorediate ............................................................................................................................................................................. 10

- Thallus isidiate ................................................................................................................................................................................ 11

10. Lobes with marginal cilia ................................................................................................................................................... P. cooperi (upper surface faintly effigurate white-maculate, soralia marginal at first, then submarginal on revolute lobe apices [ Fig. 13D ], medulla with lecanoric acid; in leeward Acacia montane forests on Réunion)

- Lobes without cilia ................................................................................................................................................... P. austrosinense (upper surface emaculate or faintly effigurate white-maculate, soralia linear and marginal [ Fig. 8D ], medulla with lecanoric acid; uncommon species on Réunion)

11. Lower surface at main lobe tips with a brown erhizinate marginal zone 1–3 mm wide, lobes 2–9 mm wide, medulla with evernic acid .......................................................................................................................................................................... P. meiospermum (lobe margins eciliate, upper surface faintly to clearly punctiform white-maculate, isidia marginal and laminal, eciliate and coralloid-branched, medulla with evernic and lecanoric acids; rare species)

- Lower surface at main lobe tips with a brown erhizinate marginal zone 4–15 mm wide, lobes 5–20 mm wide, medulla without evernic acid ..................................................................................................................................................................... P. tinctorum (lobe margins eciliate, upper surface emaculate to faintly white-maculate, isidia marginal and laminal, eciliate, simple to coralloid-branched, medulla with lecanoric acid; common species on Réunion, from sea level to the upper limit of cloud forests)

12. Thallus without vegetative propagules ........................................................................................................................................... 13

- Thallus with isidia or soralia .......................................................................................................................................................... 14

13. Pycnidia conspicuous, marginal, verruciform ( Fig. 43B ); thalline exciple smooth to rugose .................................... [ P. thomsonii ] (lobe margins ciliate, upper surface distinctly white-maculate, apothecial disc perforate, medulla with alectoronic and α-collatolic acids; very rare species not recovered on Réunion since the 19 th century)

- Pycnidia inconspicuous, immersed; thalline exciple with abundant and well-developed isidioid protuberances ( Fig. 26C ) ............ .............................................................................................................................................................................................. P. mirum (lobe margins ciliate but cilia sometimes rare, upper surface emaculate, apothecial disc perforate or imperforate, medulla with alectoronic acid (constant) with or without α-collatolic acid; uncommon species on Réunion)

14. Thallus sorediate, without isidia ...................................................................................................................... P. cf. negrosorientale (lobe margins ciliate, upper surface faintly to clearly white-maculate, soralia generally terminal at the tip of laciniae [ Fig. 27D ], never laminal, medulla with alectoronic and α-collatolic acids as major substances; uncommon species on Réunion)

- Thallus isidiate, with or without soredia ........................................................................................................................................ 15

15. Medulla with norlobaridone .............................................................................................................................................. P. mezierii (lobe margins ciliate, upper surface ± distinctly punctiform white-maculate, isidia coralloid, often ciliate [ Fig. 25C & 25D ], medulla with norlobaridone and protolichesterinic acid as major substances; uncommon species on Réunion)

- Medulla without norlobaridone ...................................................................................................................................................... 16

16. Apothecia present, usually numerous; thalline exciple with abundant and well-developed isidioid protuberances .......... P. mirum (morphotype with laminal isidia [ Fig. 26D ])

- Apothecia absent ............................................................................................................................................................................ 17

17. Isidia only present, upper cortex not fragile, medulla without α-collatolic acid ........................................................... P. crossotum (lobe margins conspicuously ciliate, upper surface emaculate or faintly white-maculate, isidia mainly marginal, often ciliate [ Fig. 17C & 17D ], medulla with alectoronic acid; uncommon species on Réunion, in montane rainforests)

- Isidia and soredia present, upper cortex fragile, medulla with α-collatolic acid .............................................................. P. mellissii (lobe margins conspicuously ciliate, upper surface emaculate or faintly white-maculate, isidia mainly marginal, often ciliate, soon becoming sorediate [ Fig. 24D ], medulla with alectoronic and α-collatolic acids; rare species on Réunion, in cloud forests)

18. Thallus without vegetative propagules ........................................................................................................................................... 19

- Thallus with vegetative propagules ................................................................................................................................................ 21

19. Medulla K+ yellow then dark red, lower surface often with rhizines to the margins, mean ascospore length <16 µm .................... ........................................................................................................................................................................................... P. cetratum (lobe margins ciliate, upper surface reticulate white-maculate, apothecial disc perforate, medulla with salazinic and consalazinic acids; very rare species on Réunion)

- Medulla K−, lower surface with a broad erhizinate marginal zone, mean ascospore length> 16 µm .......................................... 20

20. Lobes ciliate, medulla UV+ blue-white, KC+ fleeting purple pink, then pink-orange, mean ascospore length> 22 µm .................. .......................................................................................................................................................................................... P. nemorum (upper surface emaculate, rarely faintly white-maculate, medulla white, sometimes tinged with a reddish purple pigment, apothecial disc imperforate, amphithecium and stipe with ± prominent veins and coarse isidioid protuberances [ Fig. 28C ], medulla with alectoronic, protocetraric and protolichesterinic acids as major substances; uncommon in secondary lowland rainforests)

- Lobes eciliate, medulla UV−, KC+ pink, mean ascospore length <20 µm .................................................................. P. odontatum (upper surface faintly to clearly effigurate white-maculate, medulla white throughout, apothecial disc imperforate, amphithecium smooth [ Fig. 31D ], medulla with protocetraric acid; uncommon at low elevations)

21. Thallus with isidia, without soredia ................................................................................................................................................ 22

- Thallus with soralia, with or without isidia .................................................................................................................................... 29

22. Medulla K+ yellow persistent, KC− (with stictic acid) .................................................................................................................. 23

- Other medullary reactions (stictic acid absent) .............................................................................................................................. 25

23. With conspicuous laciniae (up to 10 mm long), branched and easily shed ............................................................... P. nephophilum (lobe margins ciliate but cilia sometimes rare, upper surface faintly to clearly white-maculate, marginal and submarginal isidia that mostly develop early into phyllidia and branched laciniae [ Fig. 29E ]; fairly common species on Réunion, in montane and submontane rainforests)

- Without or with occasional short (up to 1.5 mm long) laciniae ..................................................................................................... 24

24. Average thickness of the cupular proper exciple <50 µm ( Fig. 30C ) ............................................................................. P. crinitum (lobe margins ciliate, upper surface faintly to clearly white-maculate, isidia marginal and laminal, granular to coralloid, often ciliate [ Fig. 14E ]; common species on Réunion, from submontane to subalpine belts)

- Average thickness of the cupular proper exciple> 55 µm .............................................................................................. P. occultum (phenotypically similar to P. crinitum , but differs by the greater thickness of the cupular proper exciple [ Fig. 30C ] and the ITS sequence; rare species on Réunion, in cloud forests)

25. Medulla K+ yellow then red (with salazinic acid) .................................................................................................... P. subisidiosum (lobe margins ciliate but cilia sometimes rare, upper surface conspicuously reticulate white-maculate [ Fig. 40D ], isidia mainly marginal and submarginal, coralloid; uncommon species on Réunion, in submontane and montane rainforests)

- Other medullary reactions (salazinic acid absent) .......................................................................................................................... 26

26. Medulla UV+ blue-white, KC+ fleeting purple pink, then pink-orange (with alectoronic acid) .................................... P. nemorum (morphotype with some laminal or submarginal isidia [ Fig. 28D ])

- Medulla UV–, KC– or KC+ pinkish (alectoronic acid absent) ...................................................................................................... 27

27. Medulla K−, KC+ pinkish (with protocetraric acid) ............................................................................................... P. subcorallinum (lobe margins ciliate, upper surface emaculate or faintly white-maculate, isidia mainly marginal and submarginal, coralloid or arbuscular, very often ciliate [ Fig. 38D ], medulla with protocetraric and protolichesterinic acids; uncommon in the windward part of Réunion, in the submontane belt)

- Medulla K+ slowly orange brown, KC− (with succinprotocetraric acid) ...................................................................................... 28

28. Thallus moderately adnate, lobes 2–13 mm wide ................................................................................................... P. mascarenense (lobe margins eciliate or irregularly ciliate, upper surface effigurate white-maculate, isidia marginal to laminal, simple to coralloid, occasionally ciliate [ Fig. 22C ], medulla with succinprotocetraric and fumarprotocetraric acids; fairly common on Réunion)

- Thallus adnate to tightly adnate, lobes 1–4 mm wide ....................................................................................................... P. orarium (looks more like a Canoparmelia s. lat. than a Parmotrema [ Fig. 32D ], lobe margins eciliate to weakly ciliate, upper surface effigurate white-maculate, isidia marginal to laminal, simple or ± branched, rarely ciliate, usually quickly sorediate [ Fig. 32E ], medulla with succinprotocetraric and fumarprotocetraric acids; in the southeastern part of Réunion, near the coast)

29. Medulla K+ yellow persistent, KC− (with stictic acid) ............................................................................................. P. nephophilum (sorediate morphotype, Fig. 29F )

- Other medullary reactions (stictic acid absent) .............................................................................................................................. 30

30. Medulla K+ yellow then red (with salazinic acid) ......................................................................................................................... 31

- Other medullary reactions (salazinic acid absent) .......................................................................................................................... 33

31. Upper surface emaculate, rarely faintly punctiform maculate; lower surface with a broad erhizinate marginal zone ....................... ....................................................................................................................................................................................... P. cristiferum (lobe margins eciliate to clearly ciliate, soralia mainly marginal, linear to labriform [ Fig. 16D ]; uncommon in the windward part of Réunion, at low elevation)

- Upper surface reticulate maculate; lower surface often with rhizines and papillae to the margins ............................................... 32

32. Marginal zone of the lower surface of sorediate lobes dark brown or black ....................................................... P. reticulatum aggr. (lobe margins ciliate, soralia mainly capitate at the tips of laciniae or submarginal ± linear at the apex of revolute lobes [ Fig. 35F ]; common and widespread on Réunion)

- Marginal zone of the lower surface of sorediate lobes often white or white mottled .......................................... P. cf. clavuliferum (lobe margins ciliate, soralia mainly capitate at the tips of laciniae [ Fig. 12D ]; uncommon species on Réunion)

33. Medulla K+ slowly orange brown, KC− (with succinprotocetraric acid) ...................................................................................... 34

- Medulla K− or K± yellowish, KC+ pinkish (with protocetraric acid) ........................................................................................... 35

34. Thallus adnate to tightly adnate, lobes 1–4 mm wide, isidia present (at least in the early stages of development) ........ P. orarium (looks more like a Canoparmelia s. lat. than a Parmotrema [ Fig. 32D ], lobe margins eciliate to weakly ciliate, upper surface effigurate white-maculate, isidia marginal to laminal, soralia marginal to laminal [ Fig. 32F ], often originating from rapid decay of young isidia, more rarely from pustules, occasionally orbicular or subcapitate, medulla with succinprotocetraric and fumarprotocetraric acids; in the southeastern part of Réunion, near the coast)

- Thallus moderately adnate, lobes 3–8 mm wide, isidia totally absent ............................................................. P. paramascarenense (lobe margins eciliate to irregularly ciliate, upper surface effigurate white-maculate, soralia terminal at the apex of tiny laciniae when young, then labriform or subcapitate, finally spreading submarginally on revolute lobes [ Fig. 33D ], medulla with succinprotocetraric and fumarprotocetraric acids; rare species on Réunion)

35. Medulla with echinocarpic acid ...................................................................................................................................... P. dilatatum (lobe margins eciliate or very sparsely ciliate, upper surface emaculate or faintly punctiform white-maculate, soralia marginal, linear to labriform when young, then subcapitate and ± coalescing on arbuscular rising structures [ Fig. 19D ], medulla with protocetraric and echinocarpic acids as major substances; very rare species on Réunion)

- Medulla without echinocarpic acid ................................................................................................................................................ 36

36. Medulla without protolichesterinic acid ......................................................................................................................................... 37

- Medulla with protolichesterinic acid .............................................................................................................................................. 38

37. Medulla UV+, with alectoronic acid ......................................................................................................................... P. cf. deflectens (lobe margins conspicuously ciliate, upper surface emaculate or faintly punctiform white-maculate, upper cortex fragile, flaking, soralia mainly marginal, linear to labriform [ Fig. 18C ], medulla with protocetraric and alectoronic acids as major substances; very rare species on Réunion)

- Medulla UV−, alectoronic acid absent ............................................................................................................................ P. robustum (lobe margins eciliate to ± irregularly ciliate, upper surface emaculate to punctiform white-maculate, soralia marginal at the apex of laciniae when young, then labriform or subcapitate and ± coalescing [ Fig. 37D ], medulla with protocetraric acid as major substance; common species on Réunion, mainly in montane rainforests)

38. Medulla UV+, with alectoronic acid ........................................................................................................................ P. subdeflectens (lobe margins conspicuously ciliate, upper surface emaculate or faintly punctiform white-maculate, soralia either terminal labriform or subcapitate on very short laciniae [ Fig. 39C ], or marginal and ± labriform [ Fig. 39D ], medulla with protocetraric, alectoronic and protolichesterinic acids as major substances; rare species on Réunion, in leeward submontane forests)

- Medulla UV−, without alectoronic acid ......................................................................................................................................... 39

39. Soralia submarginal, often pustulate ( Fig. 42C ), never marginal linear; upper cortex fragile, here and there flaking ( Fig. 42D ); soredia granulose (mean diameter> 50 µm) ............................................................................................................... P. udisilvestre (species of the P. subarnoldii group, lobe margins conspicuously ciliate, upper surface emaculate or faintly punctiform white-maculate, medulla with protocetraric and protolichesterinic acids as major substances; uncommon in the windward part of Réunion, in the submontane belt)

- Soralia marginal, linear discontinuous, then ± labriform ( Fig. 9D & 20D ), or subcapitate at the tip of very short laciniae ( Fig. 20C ), never pustulate; upper cortex not fragile; soredia subgranulose (mean diameter <45 µm) .......................................................... 40

40. Marginal cilia short (mean length <3.5 mm) .................................................................................................... P. brachyblepharum

- Marginal cilia long (mean length> 3.5 mm) ............................................................................................................... P. eleonomum (two species of the P. subarnoldii group, lobe margins conspicuously ciliate, upper surface emaculate or faintly punctiform white-maculate, medulla with protocetraric and protolichesterinic acids as major substances; rare species on Réunion)

Figures

FIGURE 7. Parmotrema aurantioreagens. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Upper surface of lobes with marginal cilia unevenly distributed (holotype); D: Sorediate lobe with marginal soralia at the tip of short laciniae, and margin of lower surface mottled with ivory white (holotype); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; C = 5 mm; D = 4 mm; E = 10 mm.

FIGURE 8. Parmotrema austrosinense. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Krog RE33/6 & Timdal); D: Sorediate lobes with marginal linear soralia, and lower surface with erhizinate whitish marginal zone (van den Boom 40807). Scale bars:A = 10 km; C = 10 mm; D = 5 mm.

FIGURE 9. Parmotrema brachyblepharum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Type locality, a disturbed submontane Pandanus wet thicket crossed by a track; D: Sorediate lobe with marginal, linear discontinuous soralia and subgranulose soredia (Masson 974.4443); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; D = 1 mm; E = 10 mm.

FIGURE 12. Parmotrema cf. clavuliferum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4027); D: Sorediate lobes with soralia mainly capitate at the apex of laciniae, and lower surface with ivory-white marginal zone (Masson 974.4027). Scale bars: A = 10 km; C = 10 mm; D = 5 mm.

FIGURE 13. Parmotrema cooperi. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.5071); D: Sorediate lobes with marginal and submarginal soralia at revolute apices (Masson 974.5071). Scale bars:A = 10 km; C = 10 mm; D = 5 mm.

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 16. Parmotrema cristiferum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4243); D: Sparingly ciliate sorediate lobes with marginal linear and submarginal ± capitate soralia (Masson 974.4631). Scale bars: A = 10 km; C = 10 mm; D = 4 mm.

FIGURE 17. Parmotrema crossotum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C & D: Isidiate lobes with irregularly cylindrical or ± flattened, simple to ± branched, highly ciliate isidia (C: holotype, D: Masson 974.4130); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; C, D = 4 mm; E = 10 mm.

FIGURE 18. Parmotrema cf. deflectens. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Ciliate sorediate lobes with marginal, linear interrupted to somewhat labriform soralia (Krog RE34/2 & Timdal); D: small marginal soralia tinged orange by skyrin, and fragile cortex cracking (Krog RE34/2 & Timdal). Scale bars:A = 10 km; C = 5 mm; D = 1 mm.

FIGURE 19. Parmotrema dilatatum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4112); D: Eciliate sorediate lobes, with young linear interrupted to somewhat labriform soralia, and older, ± subcapitate soralia on short ascending laciniae, finally ± coalescing on arbuscular rising structures (Masson 974.4112). Scale bars: A = 10 km; C = 10 mm; D = 4 mm.

FIGURE 20. Parmotrema eleonomum. A: Distribution on Réunion (UTM 2×2 km grid system), lemon-yellow cell = specimens with molecular data, pale yellow cell with a cross = specimen without molecular data; B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C & D: Sorediate lobes with conspicuous long cilia, and soralia terminal ± subcapitate on marginal teeth or very short laciniae, or linear discontinuous on lobe margins (C: holotype, D: Masson 974.4997); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; C = 1 mm; D = 4 mm; E = 10 mm.

FIGURE 21. Parmotrema intonsum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Part of thallus with granular or cylindrical ciliate isidia and a mature apothecium with ± branched and ciliate outgrowths on margin (holotype); D: Part of thallus with ciliate phyllidia/laciniae and apothecia of various ages (Masson 974.0359); E: Gross morphology of thallus (holotype). Scale bars:A = 10 km; C = 5 mm; D = 4 mm; E = 10 mm.

FIGURE 22. Parmotrema mascarenense. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Part of thallus with laminal, ± coralloid and poorly ciliate isidia (holotype); D: Marginal cilia unevenly distributed, ± in clumps in lobe axils (Masson 974.3865); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; C = 5 mm; D = 4 mm; E = 10 mm.

FIGURE 24. Parmotrema mellissii. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4480); D: Lobes with isidia often ciliate, developing into ± coralloid-branched isidioid outgrowths becoming ± sorediate (Masson 974.5070). Scale bars:A = 10 km; C = 10 mm; D = 4 mm.

FIGURE 25. Parmotrema mezierii. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C & D: Isidiate lobes with isidia rapidly coralloid, and ± apically and/or laterally ciliate (C: Masson 974.3960, D: holotype); E: Gross morphology of thallus (holotype). Scale bars:A = 10 km; C, D = 4 mm; E = 10 mm.

FIGURE 26. Parmotrema mirum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Two mature apothecia with well-developed and ciliate isidioid protuberances on the surface of the thalline exciple (Masson 974.4275); D: Isidia cylindrical to navicular, terete to ± flattened, mostly simple (Masson 974.4274); E: Gross morphology of thallus (holotype). Scale bars:A = 10 km; C, D = 3 mm; E = 10 mm.

FIGURE 27. Parmotrema cf. negrosorientale. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.5061); D: Sorediate lobes with soralia terminal at the apex of laciniae, lower surface of sorediate laciniae ivory-white and erhizinate (Masson 974.5059). Scale bars:A = 10 km; C = 8 mm; D = 3 mm.

FIGURE 28. Parmotrema nemorum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Amphithecium of a mature apothecium developing prominent and anastomosing veins with coarse and ciliate isidioid structures (holotype); D: Submarginal isidia, ± cylindrical or flattened, rather stout, simple, often with pycnidia, some apically ciliate (holotype); E: Gross morphology of thallus (Masson 974.4635). Scale bars:A = 10 km; C = 4 mm; D = 1 mm; E = 20 mm.

FIGURE 29. Parmotrema nephophilum. A: Distribution of the isidiate/phyllidiate/laciniate form on Réunion (UTM 2×2 km grid system); B:Distribution of the sorediateform on Réunion (UTM 2×2 kmgrid system);C: Bioclimaticcharacteristics 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.

FIGURE 30. Parmotrema occultum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Transverse sections of mature apothecia of P. crinitum (left, Masson 974.5107) and P. occultum (right, holotype), stained in lactic cotton blue, showing the cupulate proper exciple clearly thicker in P. occultum; D: Isidiate lobe with ciliate, simple to coralloid-branched isidia (Masson 974.4269); E: Gross morphology of thallus (holotype). Scale bars: A = 10 km; C = 100 µm; D = 3 mm; E = 10 mm.

FIGURE 31. Parmotrema odontatum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4655); D: Apothecia of various ages, with smooth amphithecium, on lobes with eciliate margins (Masson 974.4655). Scale bars: A = 10 km; C = 20 mm; D = 8 mm.

FIGURE 32. Parmotrema orarium. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011:17–18); C: Coastal stand of Pandanus utilis, a typical habitat for P. orarium on Réunion Island (Sainte-Rose, Bois Blanc, 13August 2015); D: Gross morphology of thallus (holotype); E: Sorediate isidia (Masson 974.4646); F: Submarginal pustules, bursting into soredia (Masson 974.4221). Scale bars: A = 10 km; D = 20 mm; E = 1 mm; F = 2 mm.

FIGURE 33. Parmotrema paramascarenense. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Sorediate arbusculae in old part of thallus (holotype); D: Soralia at the apex of tiny laciniae, ± labriform or subcapitate, in young part of thallus (holotype); E: Gross morphology of thallus (Kalb & Kalb 33656). Scale bars: A = 10 km; C, D = 4 mm; E = 8 mm.

FIGURE 34. Parmotrema praesorediosum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4214); D: Sorediate lobes, with ± labriform and crescent-shaped marginal soralia (Masson 974.4215). Scale bars:A = 10 km; C = 10 mm; D = 3 mm.

FIGURE 35. Parmotrema reticulatum aggr. A: Distribution (UTM 2×2 km grid system) of specimens with molecular data on Réunion [= species 2 of Del-Prado et al. (2016)]; B: Distribution of specimens without molecular data on Réunion (UTM 2×2 km grid system); C: Bioclimatic characteristics of collection sites of specimens with molecular data (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); D: Gross morphology of thallus (Masson 974.4781); E: Part of thallus with apothecia of various ages (Masson 974.5069); F: Sorediate lobes with soralia capitate at the tip of marginal short laciniae, or submarginal ± linear at the apex of revolute lobe (Masson 974.4289). Scale bars: A, B = 10 km; D, E = 10 mm; F = 4 mm.

FIGURE 36. Parmotrema reunionicum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection site (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Sorediate lobes with marginal soralia, at first ± linear interrupted or at the tip of very short laciniae, then coalescent and forming ± rounded clusters (holotype); D: Sorediate lobe with some subcapitate submarginal soralia (holotype); E: Gross morphology of thallus (holotype). Scale bars:A = 10 km; C = 3 mm; D = 2 mm; E = 10 mm.

FIGURE 37. Parmotrema robustum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974. 4044); D: Sorediate lobes with young soralia ± labriform or subcapitate at the apex of laciniae, then ± coalescing and slightly spreading submarginally with age (Masson 974.4826). Scale bars:A = 10 km; C = 10 mm; D = 4 mm

FIGURE 38. Parmotrema subcorallinum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.4961); D: Lobes with irregular isidia, at first granular or cylindrical, then ± coralloid or arbuscular and inflated, often apically ciliate (Masson 974.4961). Scale bars: A = 10 km; C = 10 mm; D = 4 mm

FIGURE 39. Parmotrema subdeflectens. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Sorediate lobes with marginal and often branched cilia, and terminal labriform or subcapitate soralia on very short laciniae (holotype); D: Sorediate lobes with marginal and ± linear labriform soralia (Masson 974.3946); E: Gross morphology of thallus (Masson 974.3946). Scale bars:A = 10 km; C = 4 mm; D = 3 mm; E = 10 mm.

FIGURE 40. Parmotrema subisidiosum. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Gross morphology of thallus (Masson 974.3962); D: Upper surface of isidiate lobe conspicuously reticulate white-maculate, and with cylindrical, ± coralloid-branched isidia (Masson 974.3931). Scale bars: A = 10 km; C = 8 mm; D = 2 mm.

FIGURE 42. Parmotrema udisilvestre. A: Distribution on Réunion (UTM 2×2 km grid system); B: Bioclimatic characteristics of collection sites (abbreviations and threshold values for thermotype and ombrotype horizons from Rivas-Martínez et al. 2011: 17–18); C: Submarginal soralia arising from pustule-like swellings or forming from disintegration of the upper cortex of ± revolute lobe (holotype); D: Sorediate lobe with fragile, cracking and flaking upper cortex (Masson 974.4959); E: Gross morphology of thallus (Masson 974.4833). Scale bars:A = 10 km; C = 2 mm; D = 3 mm; E = 8 mm.

FIGURE 43. Parmotrema thomsonii (holotype of Parmelia pachysperma). A: Part of thallus with a mature apothecium; B: Lobes with white-maculate upper surface, and conspicuous verruciform marginal pycnidia with whitish ostiolar region. Scale bars: A = 5 mm; B = 2 mm.