Parmotrema sahyadrica Sequiera & A. Christy 2022, sp. nov.
Creators: name: Sequeira, Stephen
name: Christy, Arun
name: Anilkumar, Aswathi
name: Arsha, S. M.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Lecanoromycetes
Lecanorales
Parmeliaceae
Parmotrema
Parmotrema sahyadrica

description: Parmotrema sahyadrica Sequiera & A.Christy, sp. nov. (Fig. 1)
Mycobank no.:MB 843254
Similar to Parmotrema enteroxanthum but differs in having simple and coralloid isidia and different secondary compounds. Thallus corticolous, 7-8 cm wide, lobes 6-10 mm wide, apically rounded, sometimes crenate, eciliate, medulla yellow, isidia mainly laminal.
Type: INDIA, Kerala, Wayanad district, Kavumannam, 750m, 24 January 2019, Arun Christy 1745, (holotype KFRI!, isotype MCH!).
Thallus corticolous, loosely attached to the substratum, 7-8 cm wide; lobes apically rounded, to crenate, 6-10 mm in wide; margin eciliate; upper surface yellowish grey, centrally dark grey, emaculate, smooth, coriaceous, thallus 170-220 µm high, isidiate, less so towards margin; isidia laminal, dense, simple to coralloid, 200-300 µm high, 60- 100 µm in diameter; eciliate; lower side centrally black, wide marginal zone tan to brown, nude; rhizines sparse, simple, distributed in groups in the centre of the thallus, 0.4-0.5mm in length; medulla yellow in upper and lower part, apothecia and pycnidia absent.
Chemistry: Cortex K+ yellow, C-, KC-, P-, UV-; Medulla K+ yellow turning darker, C+ slightly yellow-red, KC-, P-TLC results: In RF class 2 an unknown compound seen as icy blue in UV which is disappearing after 6-10 hours, between RF classes 2 and 3, galbinic acid is present which is yellow coloured, entothein seen as streaking yellow to beige coloured present between RF class 3-6 and Atranorin at RF 7. (Fig. 2)
Etymology: The specific epithet refers to the type locality, Sahyadri, the Sanskrit name for the Western Ghats, where this species is distributed.
Distribution and Ecology: Found growing on Mangifera indica (Linnaeus 1753:200) in cultivated land in Kavumannam village of Wayanad district of Kerala state at an elevation of 750 m. Associated with other lichens such as Heterodermia hypocaesia (Yasuda ex Räsänen 1940:139) D.D. Awasthi (1973:113), Parmotrema tinctorum and P. cristiferum. The new species is very much restricted in its distribution and has so far only been found at the type locality.
Remarks: Parmotrema sahyadrica is characterized by a distinct yellow medulla with densely isidiate condition. This species is one among the few Indian species having a yellow-coloured medulla. Orange yellow pigmentation was occasionally reported in the lower cortical region of Parmotrema sancti-angelii and yellow coloration in the lower medulla was reported in Parmotrema permutatum (Stirton 1877 -78:252) Hale (1974:338). However, these species are different from Parmotrema sahyadrica in having a ciliate margin, farinose, marginal to submarginal soralia and different chemical reactions on the medulla. Table 1 denotes the comparison of morphological and chemical characters of P. sahyadrica with other yellow medullated Parmotrema such as Parmotrema enteroxanthum Hale (1977:434), Parmotrema endosulphureum (Hillman 1940:8) Hale (1974:336), Parmotrema sulphuratum (Nees & Flotow 1835:501) Hale (1974:339), Parmotrema sancti-angeli and Parmotrema permutatum.
description: Published as part of Sequeira, Stephen, Christy, Arun, Anilkumar, Aswathi & Arsha, S. M., 2022, Parmotrema sahyadrica (Parmeliaceae): A new species of parmelioid lichen from Wayanad, Southern Western Ghats, India, pp. 287-292 in Phytotaxa 539 (3) on pages 288-291, DOI: 10.11646/phytotaxa.539.3.8, http://zenodo.org/record/6364218