Introduction
Several taxonomic and floristic studies of lichens carried out, especially during the last two years, have made a substantial contribution to our present knowledge of the lichens of Maharashtra state of India. Although the occurrence of several lichen species has been recorded from the state, many new species are yet to be described. Our recent investigations have revealed the occurrence of 12 species of the lichen genus Leptogium from Maharashtra, which includes four species hitherto not reported from India.
The lichen genus Leptogium (Ach.) Gray is characterized by a foliose bluish grey, lead grey or brown to black thallus, a somewhat to distinctly gelatinous thallus consistency, and the cyanobacterium Nostoc as photobiont; mostly orbicular to elongate lobes with entire or rarely irregularly dissected margin; an upper surface with or without wrinkles; a lower surface with or without a hyphal tomentum; a homoiomerous thallus anatomy, corticated on both or only on the upper surface; lecanorine, laminal to submarginal apothecia; concave to plane or rarely convex, orange to red-brown smooth discs; a smooth or periclinally to longitudinally wrinkled or even minutely lobulate thalline exciple; and hyaline, acicular to ellipsoid, transversely septate or muriform ascospores. It is a widespread lichen genus with 189 species known worldwide (Kirk et al. Reference Kirk, Cannon, Minter and Stalpers2008 and various references therein). Some of the major treatments of this genus include Sierk (Reference Sierk1964), Jørgensen (Reference Jørgensen1975, Reference Jørgensen1994, Reference Jørgensen1997), Awasthi & Akhtar (Reference Awasthi and Akhtar1977, Reference Awasthi and Akhtar1979), Galloway (Reference Galloway1985), Swinscow & Krog (Reference Swinscow and Krog1988), Verdon (Reference Verdon1992), and Galloway & Jørgensen (Reference Galloway, Jørgensen, Daniels, Schulz and Peine1995).
Leptogium has 37 species in India, Sri Lanka and Nepal, and 8 species from Maharashtra, namely L. austroamericanum (Malme) C. W. Dodge, L. azureum (Sw.) Mont., L. burnetiae var. hirsutum (Sierk) P. M. Jørg., L. chloromelum (Sw.) Nyl., L. cyanescens (Ach.) Körb., L. denticulatum Nyl., L. indicum D. D. Awasthi & Akhtar, and L. javanicum Mont. (Awasthi & Akhtar Reference Awasthi and Akhtar1977, Reference Awasthi and Akhtar1979; Nayaka & Upreti Reference Nayaka and Upreti2004; Awasthi Reference Awasthi2007). In recent studies we have recognized 12 species of Leptogium from Maharashtra and discovered three species new to science which are described below, and one species recorded for the first time in India. A revised key to all non-hairy species of Leptogium from India is provided, based on the descriptions of the Leptogium species from the recent treatment of the macrolichens of India by Awasthi (Reference Awasthi2007).
Materials and Methods
A total of c. 800 specimens of Leptogium, mainly from the south-western Ghats, Eastern Himalaya, Western Himalaya and the Andaman and Nicobar Islands of India, were studied from the herbaria AMH, CAL, and from Sri Lanka from H. The present treatment, however, is the result of the morphological, anatomical and chemical studies of c. 200 specimens, belonging to 12 species of Leptogium collected from Maharashtra. The Maharashtra state is c. 800 km east-west and 700 km north-south, an irregular dentate pentagon, lying between 22o1′–16o4′ N and 72o 6′–80o 9′ E, and covering an area of 307 690 km2 (Fig. 1). Altitudes range from sea level to c. 1200 m on the Western Ghats and relative humidity fluctuates between 15–90%. The forests vary from semi-evergreen to dry deciduous types occupying nearly 21% of the total geographical area. The lichen flora of Maharashtra mainly comprises pantropical species and is dominated by crustose lichens (70% of the total lichen flora and 30% of foliose and fruticose lichens). The predominant macrolichen species in Maharashtra belong to the members of the families Collemataceae, Physciaceae, and Parmeliaceae.
Map of Maharashtra.
The specimens were examined using a stereomicroscope and a light microscope. Sections of the thalli and apothecia were stained with Lugol's iodine solution. All sections examined were mounted in lactophenol. TLC was carried out using the standard methods (Culberson & Kristinsson Reference Culberson and Kristinsson1970; White & James Reference White and James1985). All specimens were observed under UV light (365 nm).
Material was identified by comparison with the specimens in AMH, determined by P. M. Jørgensen, and with the descriptions of species (Sierk Reference Sierk1964; Jørgensen Reference Jørgensen1975, Reference Jørgensen1994, Reference Jørgensen1997; Awasthi & Akhtar Reference Awasthi and Akhtar1977, Reference Awasthi and Akhtar1979; Galloway Reference Galloway1985; Swinscow & Krog Reference Swinscow and Krog1988; Verdon Reference Verdon1992; Galloway & Jørgensen Reference Galloway, Jørgensen, Daniels, Schulz and Peine1995; Awasthi Reference Awasthi2007). The specimens recorded in the text are deposited in the Ajrekar Mycological Herbarium (AMH), Agharkar Research Institute, Pune, India.
The Species
Leptogium patwardhanii Dube & Makhija sp. nov
Similis Leptogium austroamericanum, sed excipulo proprio euparaplectenchymatico differt.
Typus: India, Maharashtra, Amboli, in semi-evergreen forest, corticolous, 690 m elev., 18 October 1974, A. V. Prabhu & C. R. Kulkarni 74.1560 (AMH—holotypus).
Leptogium species, habitus. A, L. patwardhanii (74.1560—holotype, AMH); B, L. propaguliferum (00. 216, AMH).
Scale: A, B = 5 mm.
Thallus corticolous, growing with mosses, foliose, ashy grey when dry, dark olive-green and swollen when wet, loosely attached to the substratum, 3–15 cm diam., 124–140 µm thick, irregularly lobate. Lobes orbicular, 4–9 mm broad, margin wavy, corticated on both surfaces by a single layered, 6–8 µm thick cortex. Upper surface smooth to rough, isidiate. Isidia granular to cylindrical, rarely clavate, simple to branched, laminal to marginal, concolorous with the thallus. Lower surface rough, etomentose, slightly wrinkled when wet, without tufts of hyphal hairs.
Apothecia common, scattered, laminal to marginal or submarginal, sessile, shortly stipitate or constricted at the base, 0·5–1 mm diam. Disc plane, eventually convex, epruinose, reddish brown, smooth. Thalline exciple concolorous with the thallus, with multilayered cortex. Proper exciple distinctly euparaplectenchymatous throughout. Epithecium brownish, 5–8 µm thick. Hymenium hyaline, 200–228 µm high, I+ blue. Subhymenium pale yellow to colourless, 60–80 µm thick. Asci 8-spored, cylindrical-clavate, shortly stalked, 100–120 × 12–14 µm. Ascospores ellipsoid, fusiform sometimes with one end acuminate, muriform, transversely 3–5-septate, vertically 1-septate, 20–40 × 11–13 µm.
Chemistry. Thallus K−, C−, KC−, P−, UV−; no lichen substances present.
Remarks. Leptogium patwardhanii belongs to the section Euleptogium Tuck. (TuckermanReference Tuckerman1872) and is distinguished by the presence of isidia, a multilayered cortex of the thalline exciple and a distinctly euparaplectenchymatous proper exciple and larger 20–40 × 11–13 µm ascospores. It is similar to Leptogium austroamericanum and L. cyanescens in colour, size of lobes and nature of isidia, but these two species differ in having a prosoplectenchymatous proper exciple; the proper exciple is euparaplectenchymatous in L. patwardhanii.
Leptogium coralloideum (Meyen & Flot.) Vain., an isidiate species, differs from the new species in having a plicate thallus with minute phyllidia densely crowded on the ridges and margins of the lobes, apothecia with a thick thalline exciple with a one cell layered cortex and paraplectenchymatous tissue present at the base above the photobiont layer, and minutely ornamented ascospores.
Leptogium patwardhanii is so far known only from the semi-evergreen forest of Amboli (700 m alt.) in Maharashtra state, which receives heavy monsoon rains during the months of June to September followed by a prolonged eight months dry period. Amboli has many endemic species and the new species may prove to be restricted to Maharashtra.
Additional specimen examined. India: Maharashtra: Sindhudurg District, Amboli, in semi-evergreen montane forest, 690 m elev., 1974, A. V. Prabhu & C. R. Kulkarni 74.1559 (AMH).
Leptogium propaguliferum Vain
Ann. Acad. Sci. Fenn., ser, 15(6): 40 (1921).
Thallus corticolous, foliose, loosely attached to the substratum, slate-blue, membranaceous and slightly swollen when wet, 4–6 cm diam., 50–100(–160) µm thick. Lobes orbicular, shallowly or deeply dissected, isidiate lobulate, 4–7 mm broad, corticated by a single cell layered, 5–7(–10) µm thick cortex on both sides. Isidia simple, globular to cylindrical, concolorous with the thallus, laminal to marginal, later turning into lobules. Upper surface slightly rough. Lower surface paler, with tufts of hyphal hairs here and there.
Apothecia laminal to submarginal, sessile to shortly stipitate, 0·5–2 mm diam. Disc smooth, plane, orange-brown to brown. Thalline exciple thin, rarely smooth, mostly isidiate to lobulate, with a cortical layer 6–9 cells thick. Proper exciple prosoplectenchymatous throughout. Epithecium brown, 15–25 µm thick. Hymenium hyaline, 150–225 µm high, I+ blue. Subhymenium pale yellow to colourless, 37·5–75 µm thick. Ascospores 8 per ascus, ellipsoid, muriform, transversely 3–4-septate, vertically 1-septate, 20–40 × 10–16 µm.
Chemistry. Thallus K−, C−, KC−, P−, UV−; no lichen substance present.
Remarks. Leptogium propaguliferum is somewhat similar to L. denticulatum in its external morphology but differs in the characters of the proper exciple which is prosoplectenchymatous, whereas in L. denticulatum the proper exciple is euparaplectenchymatous. With respect to the characters of the proper exciple it comes close to Leptogium indicum, L. moluccanum (Pers.) Vain., and L. azureum, but all these species have much smaller ascospores (not exceeding 25 µm in length) and also differ in other morphological characters.
Leptogium propaguliferum, recorded here for the first time from India, grows on the bark of trees in exposed conditions on the roadside, mostly in dry deciduous forests but also found in moist deciduous forests on the hill tops. This species is also known from Australia (Queensland) and the Philippines.
Specimens examined. India: Maharashtra: Kolhapur Distr., Gaganbawada to Kumbhi, on roadside Ficus bengalensis tree, 2000, B. C. Behera 00.358; Kolhapur Distr., Panhala, elev. 950 m, 1974, P. G. Patwardhan & A. V. Prabhu 74.1209, P. G. Patwardhan & C. R. Kulkarni 74.1149, 74.1209, 74.1223; Kolhapur Distr. 2000, on Mangifera indica, U. V. Makhija & K. R. Randive 00.455; Nasik Distr., Anjaneri, dry deciduous forest, 2002, U. V. Makhija & A. V. Bhosale 02.265; Nasik Distr., Bramahgiri, 2002, U. V. Makhija & A. V. Bhosale 02.267; Nasik Distr., Saptashringi, 2002, B. C. Behera & G. S. Chitale 02.256; Pune Distr., Amby valley, 26 km from Lonavala, 2003, G. S. Chitale & B. A. Adawadkar 03.251; Pune Distr., Dongarwadi, 2000, 00.138; Sinhagad, 2003, U. V. Makhija & G. S. Chitale 03.40; Pune Distr., Tamihini Ghat, 2003, N. Verma & A. A. Sonone 03.431; Satara Distr., Lingmala, 2003, B. C. Behera & G. S. Chitale 03.500; Satara Distr., Panchgani, 2001, U. V. Makhija 01.70; Sindhudurg Distr., Amboli, 1980, P. G. Patwardhan 80.483; on the way to Amboli from Ajra, 4 km from Ajra, 2000, U. V. Makhija & V. A. Mantri 00. 216; Thane Distr., Malshej Ghat, Neemgiri, 2002, U. V. Makhija & G. S. Chitale 02.240, 02.241, 02.245.
Leptogium subazureum Dube & Makhija sp. nov
Similis Leptogium azureum, sed ascosporis majoribus differt.
Typus: India, Maharashtra, Ajra to Amboli road, 4 km from Ajra, corticolous, 900 m elev., 7 December 1974, P. G. Patwardhan & A. V. Prabhu 74.2246 (AMH—holotypus).
Thallus corticolous, foliose, lead-grey when dry to dark olive-green, swollen when wet, loosely attached to the substratum, 3–15 cm diam., 50–100 µm thick, irregularly lobate; non-isidiate. Lobes flattened, orbicular, 4–8 mm broad, margin wavy, corticated on both surfaces by a single cell layered cortex of 8–10 µm, isodiametric cells. Upper surface smooth to rough, with a few wrinkles. Lower surface slightly wrinkled when wet, more or less of the same colour or slightly paler, etomentose, with tufts of hyphal hairs here and there.
Apothecia common, scattered, laminal to marginal or submarginal, sessile, or shortly stipitate, constricted at the base, solitary, 0·5–2 mm diam. Disc plane to convex, rounded, epruinose, orange-brown, smooth. Thalline exciple concolorous with the thallus, with multilayered cortex. Proper exciple distinctly euparaplectenchymatous at the margins and prosoplectenchymatous at the base. Epithecium brownish, 6–9 µm thick. Hymenium hyaline, 110–150 µm high, I+ blue. Subhymenium hyaline, 20–45 µm thick. Asci 8-spored, cylindrical-clavate, shortly stalked, 70–120 × 9–14 µm. Ascospores fusiform, thin walled, muriform, 21–44 × 8–14 µm.
Chemistry. Thallus K−, C−, KC−, P−; UV−; no lichen substances present.
Leptogium species, habitus. A, L. subazureum (74.2246—holotype, AMH); B, L. verrucosum (02.247—holotype, AMH).
Scale: A, B = 5 mm.
Leptogium species, cross sections of apothecia. A & B, proper exciple euparaplectenchymatous, L. patwardhanii (74.1560—holotype, AMH); C–F, proper exciple prosoplectenchymatous; C, D, L. propaguliferum (00. 216, AMH); E, L. subazureum (74.2246—holotype, AMH); F, L. verrucosum (02.247—holotype, AMH).
Scale: A & C = 100 µm; B, D, E, & F, = 50µm.
Remarks. Leptogium subazureum is distinguished by its non-isidiate thallus, apothecia with a euparaplectenchymatous proper exciple at the margin and a prosoplectenchymatous proper exciple at the base. It is similar to Leptogium azureum in external morphology, the colour of the thallus, the absence of isidia, and tomentum, but differs in having larger ascospores of 21–44 × 8–14 µm (ascospores are 15–28 × 8–16 µm in L. azureum).
Leptogium subazureum is one of the most common lichen species from the Western Ghats of Maharashtra and appears to be endemic in Maharashtra where it grows with mosses on exposed tree trunks and twigs in semi-evergreen forests with Leptogium javanicum and members of the Physciaceae.
Additional specimens examined. India: Maharashtra: Kolhapur Distr., Ajra to Amboli road, 4 km from Ajra, semi-evergreen forest, 900 m elev., 1974, P. G. Patwardhan & A. V. Prabhu 74.2252; Kolhapur Distr., Amba, 1974, A. V. Prabhu & M. B. Nagarkar 74.2206; Kolhapur Distr., Panhala, semi-evergreen forest, 914 m elev., 2000, U. V. Makhija & V. A. Mantri 00.493; Kolhapur Distr., Radhanagari, 2000, U. V. Makhija & B. C. Behera 00.321, 00.322; Pune Distr., Bhimashankar, 1997, U. V. Makhija 97.33A; Pune Distr., Sinhagad Fort, elev. 800 m, 2000, U. V. Makhija 00.8; Nashik Distr., Saptashringi Gad, 2002, B. C. Behera & G. S. Chitale 02.262; Satara Distr., Mahabaleshwar, Arther Seat, 8 km from Mahabaleshwar, moist deciduous forest, 1200 m elev., 1974, A. V. Prabhu & M. B. Nagarkar 74.1731, 74.1744; Satara Distr., Mahabaleshwar, 2001, B. A. Adawadkar 01.69; Satara Distr., Panchagani, 1000 m elev., 2001, B. A. Adawadkar 01.6; Sindhudurg Distr., Amboli, 1974, P. G. Patwardhan & M. B. Nagarkar 74.2359; Sindhudurg Distr., Nanapali, Amboli to Sawantwadi road, at 690 m elev., 1974, A. V. Prabhu 74.2383; Sindhudurg Distr., Mahadeogad, Amboli, 900 m elev., 2000, U. V. Makhija & B. C. Behera 00.154, 00.155; Thane Distr., Neemgiri, Malshej Ghat, 2002, U. V. Makhija & G. S. Chitale 02.242, 02.244, 02.245 (AMH).
Leptogium verrucosum Dube & Makhija sp. nov
Similis Leptogium javanicum sed thallo verrucoso differt.
Typus: India, Maharashtra, Purandar fort, saxicolous, on the walls of fort, 38 km from Pune, 1350 m elev., 13 September 2002, B. A. Adawadkar 02.247 (AMH—holotypus).
Thallus both corticolous or saxicolous, foliose, dark grey, swollen when wet, loosely attached to the substratum, 3–5 cm diam., 90–105 µm thick, irregularly lobate. Lobes orbicular, shallowly dissected, elongate, 4–7 mm broad, margin wavy, upcurved, folded, dentate, numerous wart-like pycnidia present all over the entire surface, but mostly marginal, non-isidiate, corticated on both surfaces by a single layered cortex of 7–11 µm, isodiametric cells. Upper surface smooth to rough, wrinkled. Lower surface rough, etomentose, highly wrinkled when wet, with tufts of hyphal hairs here and there.
Apothecia adnate to short stalked, sometimes constricted, reddish brown, in young condition vertical wrinkles seen on apothecia. Disc 1–3 mm diam. Thalline exciple concolorous with the thallus, with multilayered cortex. Proper exciple distinctly euparaplectenchymatous at margins and prosoplectenchymatous below. Epithecium brown, 9–15 µm thick. Hymenium hyaline, 90–105 µm high. Subhymenium hyaline, 27–30 µm high. Asci 8-spored, cylindrical-clavate, shortly stalked, 90–96 × 9–21 µm. Ascospores muriform transversely 2–4-septate, vertically 1–2-septate, ends acute, 15–32 × 6–12 µm.
Pycnidia numerous, concolorous with the thallus, marginal, giving warty appearanceto the thallus, 0·1–0·2 mm diam. Conidia bacilliform, hyaline, 3–5 × 0·7–1·7 µm.
Chemistry. Thallus K−, C−, KC−, P−; UV−; no lichen substances present.
Remarks. Leptogium verrucosum is distinguished from the other species of this genus by the presence of numerous pycnidia giving the thallus a warty appearance, the highly wrinkled upper and lower surfaces which are uneven in section with globose pycnidia embedded in the thallus and the adnate or shortly stalked apothecia having vertical wrinkles on the thalline exciple in young condition.
The new species seems to be somewhat similar to Leptogium azureum and L. javanicum Mont. in respect to the colour of the thallus, structure of the proper exciple which is distinctly euparaplectenchymatous only at the margins, and the ascospores. However, it differs from Leptogium azureum in having a vertically wrinkled thalline exciple and differs from L. javanicum in having a warty thallus owing to the presence of numerous pycnidia.
Leptogium verrucosum is a rare species and grows on rock as well as on bark in moist shady places in stunted, dry deciduous forest in rain shadow areas.
Additional specimens examined. India: Maharashtra: Nasik Distr., Bramhagiri, dry deciduous forest, 720 m elev., 2002, U. V. Makhija & A. V. Bhosale 02.268; Nasik Distr., Durgwadi, near Junnar, 2004, G. S. Chitale 04.132 (on rock); Pune Distr., Purandar Fort, 38 km from Pune, 2002, B. A. Adawadkar 02.247 (AMH).
Key to the non-hairy species of Leptogium from India
1 Thallus and/or apothecia isidiate ... 2
Thallus and apothecia without isidia ... 10
2(1) Isidia coralloid; margin of lobes and apothecia isidiate ...
... L. coralloideum (Meyen & Flot.) Vain.
Isidia not coralloid ... 3
3(2) Isidia squamiform ... 4
Isidia otherwise, globular, cylindrical, or rarely squamiform ... 5
4(3) Isidia only on thalline margin, rarely on lobe margins; thallus longitudinally wrinkled ... L. marginellum (Sw.) Gray
Isidia on lobes and also on thalline exciple; thallus slightly wrinkled; margins of the lobes isidiate, lobulate, with 2 mm wide, squamiform isidia ... ... L. denticulatum Nyl.
[synonym of Leptogium leptophyllinum (Meyen & Flot.) Vain. (Vainio Reference Vainio1921)]
5(3) Isidia rarely squamiform ... 6
Isidia never squamiform ... 8
6(5) Isidia black ... L. pichneum (Ach.) Nyl.
Isidia not black, concolorous with the thallus ... 7
7(6) Thallus lead-grey, rough, with lobules at margins; lobes up to 13 mm wide; isidia, cylindrical; apothecia isidiate ... L. cyanescens (Rabenh.) Körb.
Thallus bluish lead-grey, wrinkled; lobes 2–7 mm wide; isidia globular to rarely branched, or squamiform, laminal to marginal; Indian specimens sterile ... ... L. austroamericanum (Malme) C. W. Dodge
8(5) Isidia turning into lobules ... L. propaguliferum Vain.
Isidia not turning into lobules ... 9
9(8) Thallus strongly longitudinally wrinkled; lobes anastomosing; isidia only at margins; Indian specimens sterile ... L. millegranum Sierk
Thallus smooth, not wrinkled, not anastomosing; isidia laminal, as well as marginal ... L. patwardhanii Dube & Makhija sp. nov.
10(1) Thallus lobes anastomosing ... 11
Thallus lobes not anastomosing ... 13
11(10) Disc blackish; thallus thick, wrinkled on the both sides; lobes numerous, ascending, complicated, gelatinous; apothecia large, with thicker margin ... ... L. phyllocarpum var. crassiusculum (Taylor) Zahlbr.
Disc not blackish ... 12
12(11) Thallus grey to blackish grey, strongly wrinkled; apothecia up to 1·5 mm diam., sessile, on the thickened margin of the lobes; thalline exciple wrinkled, without lobules ... L. chloromelum (Sw.) Nyl.
Thallus dark grey to lead–grey, longitudinally wrinkled; apothecia up to 4 mm diam., subpedicellate; stalk dilated; thalline exciple wrinkled–lobulate ... ... L. phyllocarpum var. phyllocarpum (Pers.) Mont.
13(10) Thallus with numerous warts ... L. verrucosum Dube & Makhija sp. nov.
Thallus without warts ... 14
14(13) Thallus pulvinate or subpulvinate ... 15
Thallus neither pulvinate nor subpulvinate ... 17
15(14) Thallus subpulvinate; lobes erect, tufted, corniculate ... ... L. palmatum (Huds.) Mont.
Thallus pulvinate; lobes not erect, not corniculate ... 16
16(15) Thallus laciniate-lobate; upper side grey-brown, wrinkled; apothecia only on the upper side of the thallus; thalline exciple tuberculate, laciniate ... ... L. fallax Müll. Arg.
Thallus lobes elongate, orbicular; upper side dark grey to bluish grey, rough; apothecia often present on both sides of the lobes; thalline exciple periclinally wrinkled ... L. gelatinosum (With.) J. R. Laundon
17(14) Thallus consisting of sheets of tissue, not organized in distinct lobes, deeply plicate; ascspores transversely septate ... 18
Thallus organized in distinct lobes; ascospores muriform ... 19
18(17) Thallus thick; apothecia up to 3 mm diam.; thalline exciple wrinkled; ascospores 9–13(–18)-septate, 45–60 (–67) × 3–8 µm ... L. adpressum Nyl.
Thallus thin; apothecia to 1·5 mm diam.; thalline exciple entire to granulose excluded; ascospores 5–7(–9)-septate, (30–) 35–40(–45) × 5–7 (–8) µm ... ... L. brebissonii Mont.
19(17) Proper exciple euparaplectenchymatous throughout ... 20
Proper exciple euparaplectenchymatous only at margins ... 23
20(19) Thalline exciple wrinkled
Thallus terricolous, wrinkled; upper side dark grey to brown-black; cortex of thalline exciple 1–2 cell layered from base to margin; ascospores 28–53 × 9–16 µm ... ... L. platynum (Tuck.) Herre
Thalline exciple not wrinkled ... 21
21(20) Ascospores up to 25 µm long; lower side wrinkled ... L. corticola (Taylor) Tuck.
Ascospores up to 35 µm long; lower side smooth ... 22
22(21) Thallus 50–90 (–135) µm thick ... ... L. cochleatum (Dicks.) P. M. Jorg. & P. James
Thallus 80–170 µm thick ... L. ulvaceum (Pers.) Vain.
23(19) Apothecia distinctly stalked; stalk tubular ... 24
Apothecia sessile, sustipitate; stalk not tubular ... 25
24(23) Thallus with lower side wrinkled; apothecia shortly stalked, to 2·5 mm diam., stalk tubular; thalline exciple periclinally wrinkled ... ... L. indicum D. D. Awasthi & Akhtar
Thallus with upper and lower side wrinkled; apothecia somewhat dome-shaped, stalked, to 5 mm diam.; stalk to 2 mm long, dilated; thalline exciple vertically plicate, sometimes lobulate ... L. javanicum Mont.
25(23) Ascospores large up to 40 µm long; thallus smooth to rough, with few wrinkles; apothecia sessile, or shortly stipitate ... ... L. subazureum Dube & Makhija sp. nov.
Ascospores less than 30 µm long ... 26
26(25) Thallus rough, 50–100(–150) µm thick ... L. azureum (Sw. ex Ach.) Mont.
Thallus smooth, 30–60 µm thick ... L. moluccanum (Pers.) Vain.
We are grateful to Professor P. M. Jørgensen for his valuable suggestions and reviewing an early version of the manuscript. We are thankful to the Ministry of Environment and Forests, Government of India, New Delhi, for their financial support.
