Introduction
The Parmeliella mariana (Fr.) P. M. Jørg. & D. J. Galloway complex is poorly understood, particularly in the Asian/Pacific regions (Jørgensen & Sipman Reference Jørgensen and Sipman2006). Although new taxa in the group have recently been described from mainland India (Jørgensen Reference Jørgensen2003; Upreti et al. Reference Upreti, Divakar and Nayata2005; Dube & Makhija Reference Dube and Makhija2008) and from its southern islands (Makhija & Adawadkar Reference Makhija and Adawakar1999), there are still unresolved taxonomic problems in this group. These problems are mainly due to poor and few collections which are difficult to classify since there are so few characters except for the morphological ones, which are very dependant on the environment and the degree of development. A new species from Sri Lanka is described here.
Materials and Methods
The material studied is that cited below and the methods are the same as in the author's previous papers.
The New Species
Parmeliella zeylanica P. M. Jørg. sp. nov
Parmeliellae endomiltae similis, sed thallo minute squamuloso, crasso, medulla dilute ochraceae pigmentosa; sporae minutae et guttiformae.
Typus: Sri Lanka, Central Prov., Nuwara Eliya, near the Golf Club, on more or less solitary trees, alt.1850 m, 22 March 1964 G. Degelius As-438 (UPS— holotypus).
(Fig.1)
Parmeliella zeylanica (holotype). A, habitus; B, detail of apothecia. Photographs by J. Berge. Scales: A = 1mm; B = 2mm.
Thallus brown, squamulose, forming orbicular patches to 5 cm of imbricating lobes to 1mm wide, 130–150 μm thick, without a thick mat of rhizohyphae, but occasionally with a few bundles of projecting rhizohyphae. Upper cortex distinct, cellular, to 30–40 μm upon a loose medullary layer, enclosing packets of Nostoc, individual cells of which are 3–5 μm. Lower cortex absent.
Apothecia laminal, sessile, to 1·5 mm diam. with distinct squamulose thalline margin obscuring the proper margin; disc brown, plane. Hymenium 75–100 μm high, I+ blue, made up of simple, septate hyphae, apically thickened, with external dark brown pigment. Asci narrowly subcylindrical, 60–70 × 5–7 μm, apically with internal amyloid ringstructure; 8-spored. Ascospores drop-like, simple, colourless, 10–12 × 4–6 μm, with distinct rugulose exospore tapering in the lower end.
Conidiomata not seen.
Chemistry. All reactions negative. No lichen substances present, but with a K+ intensifying pale yellow-orange, unknown pigment that is best observed after K has been added.
Ecology and distribution. As yet known only from the highlands of southern Sri Lanka where it grows on trees (and tree ferns). Possibly a local taxon, related to two other species in the region.
Additional specimens examined. Sri Lanka: Central Prov: Nuwara Eliya, Grand Hotel, on tree fern in garden, alt. 1850, 1964, G. Degelius As-483 (UPS); Horton Plains, 2008 Jugalal Udeni (HAKS).
Notes. Despite its atypical appearance, this new species is a member of the Parmeliella mariana group, because of the distinct thalline margin of the apothecia and the apical amyloid ring structure of the asci. It differs from most hitherto known species of this group in the lack of radiating marginal lobes resting on a thick blackish mat of rhizohyphae. This latter character is often also poorly developed in the closely related Parmeliella endomilta Vain., a widespread paleotropical species (Jørgensen & Sipman Reference Jørgensen and Sipman2006), which has a placodioid, thinner (50–75 μm), more skin-like thallus with a strongly orange medulla, and larger citriform spores.
There is another closely related species described from Sri Lanka, Pannaria leiostroma Nyl., which needs to be transferred to Parmeliella because of the ascal characters which are the same as in Parmeliella zeylanica:
Parmeliella leiostroma (Nyl.) P.M. Jørg. comb. nov.; basionym: Pannaria leiostroma Nyl. in Leighton, Trans. Linn. Soc. London 27: 165 (1869).
This species differs from Parmeliella zeylanica in being thinner with confluent, skin-like lobes, and lacking any pigmentation in the medulla, and also by the larger ascospores, 12–15 × 5–7 μm. One might expect the recently described Parmeliella endomilta var. achromatica Makhija & Adaw. to be a synonym of P. leiostroma. However, examination of an isotype (BG) revealed that it has a rather thick thallus with discrete radiating marginal lobes resting on a prominent mat of blackish rhizohyphae. The characters of the apothecia are also in agreement with those of Parmeliella mariana, so it is best placed in synonomy with that species.
Emended key to brightly coloured species of Parmeliella in Jørgensen (Reference Jørgensen and Sipman2006)
1 Thallus with a yellowish hue, medulla not pigmented (Phillipines, New Guinea) ... ... P. flavida P. M. Jørg.
Thallus grey-brown with yellow or orange medulla ... 2
2(1) Thallus small-squamulose, not resting on thick mat of rhizohyphae; medulla faintly pigmented (Sri Lanka) ... P. zeylanica P. M. Jørg.
Thallus placodioid resting on thick mat of rhizohyphae, medulla strongly pigmented ... ... 3
3(2) Thallus greyish with citrine yelow medulla, lobes discrete, spores shorter than 15 μm (Phillipines, Borneo, New Guinea) ... P. endolutea P. M. Jørg.
Thallus brownish with bright orange medulla, lobes confluent, spores longer than 15 μm (widespread paleotropical) ... P. endomilta Vain.
I am indebted to the directors and curators of the herbaria cited for sending me material on loan. I thank Pat Wolseley for letting me examine her recently collected material from Sri Lanka and Udeni Jayalal for allowing me to include his material. Tor Tønsberg kindly assisted in chemical studies and Jan Berge took the photographs. Thanks to both, as well as to Beate Helle for making the photograph ready for printing.
