Introduction
Pyrenula, a cosmopolitan lichen genus of c. 200 species, is most diverse in tropical regions (Aptroot Reference Aptroot, Nash, Rayan, Gries and Bungartz2002). Harris (Reference Harris1989) discussed the circumscription of the genus and merged several genera under Pyrenula. Subsequently, Harris (Reference Harris1995) and Aptroot et al. (Reference Aptroot, Diederich, Sérusiaux and Sipman1997, Reference Aptroot, Lücking, Sipman, Umana and Chaves2008) made further significant contributions to the genus. Upreti (Reference Upreti1998) revised the genus in India and recognized 78 species. During the course of our lichenological studies in Eastern India (Assam and West Bengal), the genus Pyrenula has also been studied. The investigation has resulted in the discovery of a new species and six new records for India. The new species is described below as Pyrenula darjeelingensis, and brief notes of the new records are also provided.
Materials and Methods
Specimens collected from eastern India and deposited in BSA and CAL herbaria were examined. External morphology was studied using an Olympus stereomicroscope. Thin hand-cut sections of thalli and ascomata were mounted in water, 10% KOH solution and iodine solution and examined with a Leica DM 2500 microscope.
The New Species
Pyrenula darjeelingensis Jagadeesh Ram & G. P. Sinha sp. nov
Thallus flavido-brunneus, sine pseudocyphellis, corticatus. Perithecia emergentia, globosa vel subglobosa, 0·5–1 mm lata, hymenio insperso, ascosporis (3–)5-septatis vel submuriformis, 23–29(–33) × (8–)9–13(–14) μm.
Typus: India, West Bengal, Darjeeling, Happy Valley Tea Estate, alt. c. 2100 m, on shade tree, 16 May 2005, V. N. Singh 2248 (BSA—holotypus).
Fig. 1. Pyrenula darjeelingensis, habit (holotype). Scale = 1 mm.
Fig. 2. Pyrenula darjeelingensis, ascospores. (holotype). Scale = 10 μm.
Thallus crustose, corticolous, epiphloeodal, irregular, up to 6 cm across, yellowish brown to yellow-orange, continuous, smooth, not pseudocyphellate, K−, UV−, corticate; prothallus indistinct; cortex yellowish, 40–95 μm thick; photobiont layer 16–40 μm thick; photobiont Trentepohlia.
Perithecia solitary, initially immersed, later semi-immersed to emergent, globose to subglobose, occasionally hemispherical, 0·5–1 mm diam. Ostiole apical, pale, often indistinct. Perithecial wall complete, spreading laterally, carbonized, lacking crystals, 16–27 μm thick at base, 43–115 μm thick laterally. Hymenium hyaline, fully inspersed, I+ orange. Paraphyses unbranched, 1 μm thick. Asci clavate, 8-spored. Ascospores uniseriate to sub-biseriate, grey-brown, ellipsoid to fusiform, with papillate ends, transversely (3–)5-septate to submuriform with 1 longitudinal septum in the middle, distoseptate, with 1–5 incomplete eusepta, 23–29(–33) ×(8–)9–13(–14) μm; lumina angular, occasionally rounded; terminal lumina mostly not separated from the exospore by an endospore layer.
Remarks. Pyrenula darjeelingensis is characterized by the (3–)5-septate to submuriform ascospores with papillate ends and the terminal lumina mostly not separated from the exospore by an endospore layer. It resembles P. erumpens R. C. Harris in ascospore morphology, but the latter species has an eccentric to lateral ostiole, non-inspersed hymenium, 5–8-septate to submuriform larger ascospores (45–65 × 20–25 μm). Pyrenula concatervans (Nyl.) R. C. Harris is another species having 3–5-septate to submuriform ascospores, but it has non-inspersed hymenium, ascospores with rounded ends, and the terminal lumina are separated from the exospore by a thick endospore layer and by the post-mature ascospores containing reddish oil. Pyrenula quinqeseptata Aptroot also closely resembles the new species, but it differs in having I+ blue hymenium and consistently transversely 5-septate ascospores that lack eusepta (Aptroot et al. Reference Aptroot, Diederich, Sérusiaux and Sipman1997, Reference Aptroot, Lücking, Sipman, Umana and Chaves2008; Harris Reference Harris1989). At present the new species is known only from the type locality.
New Records
Pyrenula acutalis R. C. Harris
This species has been found to be common in the plains and foot hills of Assam and West Bengal. Harris (Reference Harris1989) stated that the species is endemic to Louisiana (USA), but recently Aptroot (Reference Aptroot2003) and Aptroot et al. (Reference Aptroot, Lücking, Sipman, Umana and Chaves2008) reported it from Taiwan and Costa Rica, respectively.
Specimens examined. India: Assam: Sibsagar district, Rajabari T. E., on tea bark, 2004, Jagadeesh Ram & V. N. Singh 1401A (BSA); Karbi Anglong, Silonijan, Sobhaneswari T. E., on shade tree, 2005, V. N. Singh 1773 (BSA); North Cachar Hill, Borjalanga, Rosekandy T. E., on shade tree, 2005, V. N. Singh 1814 (BSA); ibid., Pailapool, Dewan T. E., on shade tree, 2005, V. N. Singh 1904 (BSA); ibid., Sonai, Binnakandy T. E., on shade tree, 2005, V. N. Singh 1930 (BSA); ibid., Jalalpur, Jalapur T. E., on shade tree, 2005, V. N. Singh 2056 (BSA); Tinsukia, Makum Road, Abandoned T. E., on shade tree, 2006, G. P. Sinha & V. N. Singh 2960 (BSA); ibid., on tea bark, G. P. Sinha & V. N. Singh 2974 (BSA); Lakhimpur, Jonai Road, Ananda T. E., on shade tree, 2006, G. P. Sinha & V. N. Singh 3203 (BSA); Tezpur, Rangapara, Ghoirallia T. E., on tea bark, 2006, G.P. Sinha & V.N. Singh 3369 (BSA); Dubri, Choper, Choper T.E., on tea bark, 2006, G. P. Sinha & V. N. Singh 3486 (BSA). West Bengal: 24-Parganas district, Sundarbans Biosphere Reserve, Tentulia, 1975, Roychowdhury 2103 (CAL); ibid., Namkhana, Narayanpur, 1973, Roychowdhury 2882 (CAL); Jalpaiguri district, Kalchni, Kalchini T. E., on shade tree, 2005, V. N. Singh 2430 (BSA).
Pyrenula dermatodes (Borrer) Schaer
This subcosmopolitan species has been found on the hilly slopes of the Neora Valley National Park in the Eastern Himalaya. Usually it reacts UV+ yellow due to the presence of lichexanthone, but specimen 4338 is UV− and 4341 is partly UV+ yellow.
Specimens examined. India: West Bengal: Darjeeling, Neora Valley National Park, Neora river bank, N 27° 06′ 30.39″, E 88° 43′ 04.0″, alt. 2245 m, 2008, Jagadeesh Ram 4338 (BSA); ibid, N 27° 05′ 50.4″, E 88° 43′ 29.1″, alt. 2189 m, 2008, Jagadeesh Ram 4341 (BSA).
Pyrenula mastophoroides (Nyl.) Zahlbr
Apparently this is a pantropical species, previously known from the Neotropics. It has been found on the hill slopes of Neora Valley National Park in the Eastern Himalaya.
Specimen examined. India: West Bengal: Darjeeling, Neora Valley National Park, Aloobari, N 27° 07′ 26.3″, E 88° 43′ 06.3″, alt. 2435 m, 2008, Jagadeesh Ram 4434 (BSA).
Pyrenula mucosa (Vain.) R. C. Harris
This pantropical species has been collected on the hill slopes of Neora Valley National Park in the Eastern Himalaya.
Specimen examined. India: West Bengal: Darjeeling, Neora Valley National Park, Aloobari, N 27° 07′ 26.3″, E 88° 43′ 06.3″, alt. 2435 m, 2008, Jagadeesh Ram 4434 (BSA).
Pyrenula subelliptica (Tuck.) R. C. Harris
This pantropical species has been found to be common on the plains of Assam and West Bengal. Specimens from India have a non-inspersed hymenium, but those from North America have an inspersed hymenium (Harris Reference Harris1989).
Specimens examined. India: Assam: Nagaun, Solanath T.E., on shade tree, 2005, V. N. Singh 1579 (BSA); Karbi Anglong, Silonijan, Sobhaneswari T. E., on shade tree, 2005, V. N. Singh 1695, 1770 (BSA); North Cachar Hill, Pailapool, Dewan T. E., on shade tree, 2005, V. N. Singh 1831, 1892, 1920 (BSA); ibid., Sonai, Binnakandy T. E., on shade tree, 2005, V. N. Singh 1850 (BSA); ibid., Jalalpur, Jalapur T. E., on shade tree, 2005, V. N. Singh 2009, 2088 (BSA); Tezpur, Biswanath Charlie, Monabari T. E., on shade tree, 2006, G. P. Sinha & V. N. Singh 3450 (BSA). West Bengal: Jalpaiguri district, Hatipota, Jaianti T. E., on shade tree, 2005, V. N. Singh 2405 (BSA).
Pyrenula thelemorpha Tuck
This pantropical species has been found on a non-mangrove tree introduced into a mangrove reserve.
Specimen examined. India: West Bengal: Sundarbans Biosphere Reserve, Haldibari forest camp, on Albizia, 2004, Jagadeesh Ram 906A (BSA).
We thank Dr M. Sanjappa, Director, Botanical Survey of India, Kolkata, and Dr K. P. Singh, Additional Director, Botanical Survey of India, Central Circle, Allahabad for facilities. We are grateful to the Ministry of Environment and Forests, New Delhi for financial assistance.
