Parmotrema austrosinense (Zahlbr.) Hale (1974a: 335) 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 : 22-24

Parmotrema austrosinense (Zahlbr.) Hale (1974a: 335) MycoBank no. 343014

Parmelia austrosinensis Zahlbr. in Handel-Mazzetti (1930: 192) MycoBank no. 397194

Type:— CHINA. Guizhou: near Gwanyinschan, not far from Guiyang , 1250 m, living branches of Camellia sinensis in the warm temperate zone, 6 July 1917, H. Handel-Mazzetti 10580 (US [image!], lectotype designated by Hale 1959; WU [image!], W [image!] isolectotypes) .

( Fig. 8 )

Thallus foliose, moderately adnate, subcoriaceous, up to 6 × 2.5 cm. Lobes rounded, imbricate, irregularly branched, 2–8 mm wide, rarely plane but most often concave, with margins undulated, ascendant, smooth or slightly crenate, eciliate ( Fig. 8C ). Upper surface grey-green, emaculate or faintly effigurate white-maculate, smooth near lobe tips but wrinkled in the older parts, sorediate, lacking schizidia, pustules, dactyls, lobules, phyllidia and isidia. Soralia linear and marginal (and rarely orbicular submarginal in the Mauritian specimen) ( Fig. 8D ). Soredia farinose, (20)– 30.3 –(45) µm in diameter (n = 60, from 3 specimens, SD = 6.4 µm). Medulla white throughout. Lower surface rugulose, black and mat in the central part, erhizinate marginal zone (ca. 3–8 mm wide) more or less shiny, ivory white ( Fig. 8D ), sometimes mottled with brown at the sorediate lobes, light chestnut brown at the non-sorediate ones. Rhizines concolor to the lower surface, sparse to moderately dense, in the central part, up to 0.8 mm long, mostly simple but occasionally 1–2 times branched. Apothecia absent. Pycnidia submarginal towards apices, black. Conidia not found (13 pycnidia investigated).

Chemistry:— Spot tests and fluorescence: upper cortex K+ yellow, UV−; medulla K−, C + red, KC + red, P−, UV−. Secondary metabolites ( TLC): upper cortex with atranorin and chloroatranorin; medulla with lecanoric acid.

Geographical distribution:—Pantropical species that extends into some warm-temperate areas ( Hale 1965a, Louwhoff 2001, Kurokawa 2006). It seems to be widespread in Madagascar ( des Abbayes 1961, Aptroot 1990) but there is no mention from the Seychelles ( Seaward & Aptroot 2009, Diederich et al. 2017). In the Mascarene Islands, this taxon is apparently rare, known from only two localities on Réunion (van den Boom et al. 2011, present work, Fig. 8A ) and only one on Mauritius (present work).

Ecology:—In the Mascarene Islands and Madagascar, corticolous on trunks and branches of various trees or shrubs ( Cryptomeria , Erica , Ficus , Jacaranda , Mangifera , Uapaca , Vernonia ). One of the two collections for Réunion was on an introduced tree species ( Cryptomeria japonica D. Don ), in an anthropized environment (picnic area). Bioclimate of this locality (800 m elevation) is pluvial tropical in the upper thermotropical belt (It = 495) and the upper humid ombrotype belt (Io = 11.4). The bioclimate of the second locality (1190 m elevation) is also pluvial tropical with an ombrotype belt upper humid (Io = 10.9), and a thermotype belt lower mesotropical (It = 415) ( Fig. 8B ). For this location, the phorophyte and the habitat are not known.

Notes:—Among the Reunionese species of Parmotrema , P. austrosinense may be confused with P. cooperi . Both have linear marginal soralia and lecanoric acid in the medulla; however, P. cooperi has a more coriaceous thallus and ciliate lobes.

The typification of P. austrosinense is confused ( Spielmann & Marcelli 2009). Hale (1959) designated Handel-Mazzetti 10580, from the Plitt lichen herbarium (BPI), as the lectotype. The other collection (Handel-Mazzetti 8209) conserved in BPI was attributed by him to Cetrelia cetrarioides . Later on, however, in his monograph ( Hale 1965a), he cited Handel-Mazzetti 10580 from WU as the lectotype, with isolectotypes in BPI and W. Subsequent authors either follow Hale (1965a) for the lectotypification (e.g. Krog & Swinscow 1981, Elix 1994, Divakar & Upreti 2005) or follow Hale (1959) (e.g. Spielmann & Marcelli 2009), but without having examined the type collections. Images of the specimens can be seen in the virtual herbaria of US, W and WU. The two collections housed at US are in accordance with Hale (1959): Handel-Mazzetti 10580 ( US 00068729) is marked ‘lectotype’, handwritten on a Hale label dated 1959, and Handel-Mazzetti 8209 ( US 00068730) is not a Parmotrema , being pseudocyphellate. The collection Handel-Mazzetti 10580 at WU (WU 069715) has a Hale label with the handwritten indications ‘lectotype’, underlined twice, and with two dates: 1962 and 1989; the specimen kept at W (W-KRYPT 1923-0004751) has a handwritten annotation ‘lectotype’ by Hale dated 1962. The Handel-Mazzetti 8209 specimens at WU (WU 069727) and W (W-KRYPT 1926- 0002226) both contain, at least in part, a pseudocyphellate species. As Hale’s 1959 lectotypification is valid, the 1965 lectotypification has no status and can be disregarded.

This species is photophilous and drought tolerant ( Krog 1987). In eastern and southern Africa, it is common in dry and well-lit sites such as semi-arid open tree savannas ( Hale 1965a, Krog & Swinscow 1981, Zedda et al. 2009). Thus, the apparent scarcity of P. austrosinense on Réunion is perhaps explained by the fact that we did not survey the driest habitats of the island, located at low elevation in its western part.

Parmotrema austrosinense was resolved as sister to all accessions of P. tinctorum ( Fig. 3 ), a widespread species also producing lecanoric acid, but with a different morphology and producing isidia. In our phylogenetic tree based on ITS sequences ( Fig. 4 ), the specimen from Mauritius nests in a well supported clade with collections from South Korea and Canary Islands.

Specimens examined:— FRANCE. Réunion: Cilaos, where the road crosses Ravine Pissa, elev. 1190 m, 21°06’57”S, 55°27’26”E, on bark of twig, 02 October 1996, H. Krog RE33/6 & E. Timdal (O L-231250); Petite-Île, Manapany les Hauts, elev. 800 m, 21°19.6’S, 55°35.2’E, open picnic place with mature Cryptomeria japonica trees, shrubs and mixed trees, including orchard with fruit trees, on Cryptomeria , 07 June 2008, P. & B. van den Boom 40807 ( Hb. van den Boom).

MADAGASCAR. Alaotra-Mangoro : Amparafaravola , lac Alaotra , végétation sur dune sableuse, June 1955, J. Bosser 8083 ( REN 000084 ); Androy: Ambovombe, elev. 100 m, bush dégradé sur sable, November 1956, J. Bosser 10.131 parte ( REN 000085 ) .

MAURITIUS. Moka District: Réduit, State House Park , elev. 280 m, 20°13’43”S, 57°29’13”E, on Ficus microcarpa , 30 August 2019, P. Diederich 19278 (Hb. P. Diederich) .

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 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.