Introduction
This paper introduces a new corticolous species from Brazil, Rinodina brasiliensis, mainly characterized by its isidiate thallus (Fig. 1A) lacking secondary lichen substances and its large Pachysporaria-type ascospores, with walls not ornamented, but including globular inclusions surrounding the lumina. The last feature clearly relates the new species to R. dolichospora and R. guianensis. These taxa are also discussed and included in the key to the species presented in this contribution.
The key character of the three species mentioned above is the unique shape of their ascospores. Between the lumina and the outer spore-wall, there are abundant, minute, scattered, seldom contiguous, inclusions, which can clearly be seen in young but already brown-pigmented ascospores (Figs. 2C, 3A). As the ascospores mature, the drops (inclusions) increase in size and number, approaching and closely surrounding the lumina (Figs. 2D, 3B–C, 4D). Finally, in overmature ascospores, the lumina are almost completely covered (overcast), and therefore hidden, by large drops. The origin and nature of these drops or inclusions are at present uncertain (Fig. 2E).
These globular structures are different from the sporoblastidia present in the Polyblastidium-type ascospores of Heterodermia, described and illustrated in Kurokawa (Reference Kurokawa1962, under Anaptychia) and Poelt (Reference Poelt1965). In contrast, the sporoblastidia arise or bud from the lumina and remain united to them for a long time, are larger, of variable shape, often elongate, and, according to Kurokawa (op. cit.), they are true cells. For comparison, see the photographs of the sporoblastidia of Heterodermia flabellata (Fée) D. D. Awasthi in Schumm. & Schäfer-Verwimp (Reference Schumm and Schäfer-Verwimp2006: 36; Abb. 2).
Other characters that these treated species have in common are: 1) rather large, smooth ascospores without a torus belonging to the Pachysporaria-type; 2) crustose to subsquamulose, thin, smooth and ochraceous to brownish thallus; 3) tall hymenium (up to 150 μm high); 4) orange-brown epihymenium composed of richly branched and interwoven paraphyses; 5) Lecanora-type asci; and 6) small photobiont cells. Furthermore, all of them are known from tropical to subtropical areas and reach temperate regions in Australia and south-western Europe.
The terricolous Rinodina intermedia Bagl., a species with a world-wide distribution, presents most of the characters cited above. However, apart from its ecology, it is distinguished, by its mature submuriform ascospores with 4–12 locules (Mayrhofer et al. Reference Mayrhofer, Sheard, Grassler and Elix2001). Sampaio (Reference Sampaio1924) has indicated its close relationship with R. confinis.
Another species related to this group is R. inspersoparietata Giralt & van den Boom, recently discovered in the Cape Verde Islands. It is saxicolous and is treated in detail in a paper including all Rinodina species hitherto known from these islands (Giralt & van den Boom Reference Giralt and van den Boom2008). Apart from its different habitat, it is easily separated from R. brasiliensis and R. guianensis by a lack of isidia; from R. dolichospora by having smaller ascospores, of 17–23 × 7·5–12 μm, which develop after an ontogeny of type B; and from R. intermedia by possessing Pachysporaria-type ascospores. Because of their close relationship with R. dolichospora, R. intermedia and R. inspersoparietata are also included in the key, but in parentheses.
Materials and Methods
All descriptions are based on our personal examinations. The specimens were examined by standard techniques using stereoscopic and compound microscopes. Current mycological terminology generally follows Kirk et al. (Reference Kirk, Cannon, David and Stalpers2001). Only free ascospores lying outside the asci have been measured. The terminology used for the asci follows Rambold et al. (Reference Rambold, Mayrhofer and Matzer1994) and for the ascospore-types and ascospore-ontogenies Giralt (Reference Giralt2001).
The standard methods of thin-layer chromatography (TLC) (e.g. Culberson & Ammann Reference Culberson and Ammann1979; Culberson et al. Reference Culberson, Culberson and Johnson1981; Culberson & Johnson Reference Culberson and Johnson1982) were employed for the search of chemical constituents.
Key to the Rinodina dolichospora group
1 Thallus never isidiate 2
Thallus isidiate 4
2(1) Terricolous; young ascospores with four lumina, similar to the Conradia-type; mature ascospores submuriform, with 6–12 lumina, (20–)25–30 × 12–15(−18) μm (R. intermedia)
Saxicolous or corticolous; young and mature ascospores with two lumina, Pachysporaria-type 3
3 (2) Saxicolous; ascospores 17–23 × 7·5–12 μm, ontogeny type B (R. inspersoparietata)
Corticolous; ascospores (20–)25–35(−40) × 11–18 μm, ontogeny type A R. dolichospora
4 (1) Isidia (50–)70–90(−100) μm wide; ascospores (24–)26–33(−40) × (10–)13–16(−18) μm, ontogeny type A R. brasiliensis
Isidia (20–)30–40(−50) μm wide; ascospores (14–)16–19(−22) × (6·5–)8–10(−12) μm, ontogeny type B. R. guianensis
The Species
Rinodina brasiliensis Giralt, Kalb & H. Mayrhofer sp. nov
Rinodina dolichospora similis sed thallus isidiatus. Isidia numerosa, subcontigua ad densa, simplices vel ramosa, ad 0·4 mm alta, circa 0·1 mm crassa, thallo concolora.
Type: Brazil, Rio de Janeiro, Serra da Mantiqueira; Itatiaia, between Registro do Picú and Agulhas Negras, on Cupressus by the roadside, 1500 m, 22°20′ S, 44°45′ W, 12 July 1979, K. Kalb (hb. Kalb 37183—holotypus; GZU—isotypus).
Rinodina species, habit. A, R. brasiliensis (holotype); B, R. guianensis. [Kalb s. n. (hb. Kalb 37186)]. Scales: A = 0·475 mm; B = 0·5 mm.
Rinodina brasiliensis, ascospores showing the peculiar globular inclusions within the spore wall (holotype). A, type A ontogeny; B–C, Pachysporaria-type ascospores; C, minute, scattered inclusions; D, larger inclusions surrounding the lumina; E, coalescent inclusions partially hiding the lumina. Scale = 10 μm.
Thallus corticolous, crustose to subsquamulose, with numerous isidia, free or mostly united at the base into a subsquamulose structure (Fig. 1A), covering wide areas, thin, smooth, ochraceous to brownish.Isidia (100–)200–400 μm long × (50–)70–90(−100) μm wide, simple to branched, concolorous with thallus.
Apothecia lecanorine, sessile, broadly attached, becoming more or less constricted at the base, usually scattered, (0·3–)0·5–0·8(−1) mm diam. Thalline margin concolorous with thallus, thin, entire, becoming isidiate, finally partially excluded. Disc dark brown, plane to subconvex. Proper margin entire, thick, prominent, clearly visible as a ring within the thalline margin, persistent. Excipulum thallinum up to 100 μm wide. Cortex nearly indistinct, not expanded below. Excipulum propium 10–20 μm laterally, expanded to (40–)60–100 μm above. Hymenium 120–150(−180) μm high. Epihymenium orange-brown. Hypothecium pale yellowish-brown, to 50 μm deep. Paraphyses 1–1·5 μm wide, richly branched and interwoven at epihymenium level. Apices up to 3(−4) μm wide. Asci Lecanora-type, 110–130 × 15–28 μm. Ascospores Pachysporaria-type, (24–)26–33(−40) × (10–)13–16(−18) μm, smooth, walls not ornamented, including globular inclusions surrounding the lumina, without torus, ontogeny type A (Fig. 2A–E, 5A).
Pycnidia and conidia not seen.
Chemistry. No substances detected by TLC.
Observations. Rinodina brasiliensis is characterized by the thin, smooth, and ochraceous thallus, composed of scattered to contiguous, entire to sublobate squamules which dissolve into large, simple to branched isidia, and the large smooth, Pachysporaria-type ascospores, not constricted at septum, without a torus and including globular inclusions in the spore wall. The large isidia together with the large ascospores separate this new taxon from all the other species treated here. All specimens hitherto known are fertile. Rinodina brasiliensis is very closely related to R. dolichospora from which it differs only in the presence of isidia. According to the original description of Malme (Reference Malme1902), R. dolichospora may be “crebe brevissimeque isidiosus”. As noted in Mayrhofer et al. (Reference Mayrhofer, Kantvilas and Ropin1999), the squamules of R. dolichospora are “at times present ascending margins somewhat microphylline or lobulate” but they are never clearly isidiate as in R. brasiliensis.
A morphologically similar species possessing larger isidia united at the base into a subsquamulose structure and large Pachysporaria-type ascospores, is the oceanic-temperate R. isidioides, which is distinguished by the presence of atranorin (Giralt et al. Reference Giralt, Mayrhofer and Sheard1995; Giralt Reference Giralt2001).
Ecology and distribution. The new species was found on the trunks of well-lit trees at the edge of a tropical rainforest, called mata atlântica, in parts disturbed by human activity. It is known only from the Serra da Mantiqueira (SE Brazil).
Additional specimen examined. Brazil: São Paulo: Serra da Mantiqueira; above Campos do Jordão, c. 45 km N von Taubaté, on a free standing Podocarpus sp., 1850 m, 22°45′S, 45°35′ W, 1978, K. Kalb & G. Plöbst (hb. Kalb 37184).
Rinodina dolichospora Malme
Bihang K. Svenska Vet.-Akad. Handl. 28 (III/1): 30 (1902); type: Brazil, Matto Grosso, Santo Antonio, Morro Grande, ad truncum dejectum in siulvula humidam, 1893, G. O. Malme 2159 (S—lectotype! Mayrhofer et al. Reference Mayrhofer, Kantvilas and Ropin1999: 183).
New synonym: Rinodina confinis Sampaio, Bolet. Soc. Broter. Ser. 2, 2: 177 (1924); type: Portugal, Minho, Póvoa do Lanhoso, S. Gens, August 1919, G. Sampaio (UPS—syntype).
Exs.: SAMPAIO: Lich. exs. Portugal 198 (M, as R. confinis).
(Fig. 3A–C)
Rinodina dolichospora, ascospores [Kalb s. n. (hb. Kalb 37185)]. A–C, Pachysporaria-type ascospores showing the evolution of the globular inclusions within the spore wall. Scale = 10 μm.
Thallus corticolous, crustose to subsquamulose, ochraceous to olivaceous, composed of entire to sublobate squamules, sometimes with ascending margins.
Apothecia lecanorine, 0·4–0·6(–1) mm diam. Hymenium up to 170 μm tall. Epihymenium orange-brown. Hypothecium pale yellowish-brown. Ascospores Pachysporaria-type, (20–)25–35(−40) × 11–18 μm, smooth, walls not ornamented but including globular inclusions surrounding the lumina without torus, ontogeny of type A (Fig. 3A–C). Sometimes the European material possesses a few ascospores showing tendencies towards four lumina.
Conidia 4·5-6 × 1·5 μm.
Additional information including detailed descriptions is given in Sampaio (Reference Sampaio1924), Magnusson (Reference Magnusson1947), Giralt & Mayrhofer (Reference Giralt and Mayrhofer1995) and Giralt (Reference Giralt2001), under R. confinis, and Mayrhofer et al. (Reference Mayrhofer, Kantvilas and Ropin1999) and Sheard & Mayrhofer (Reference Sheard and Mayrhofer2002), under R. dolichospora.
Chemistry. No substances could be detected by TLC.
Observations. The lack of vegetative propagules together with the large Pachysporaria-type ascospores distinguish this species from all the other species treated here.
Distribution. Rinodina dolichospora is hitherto known from several localities in the Atlantic coast of the Iberian Peninsula and from Italy (Liguria), Europe (Giralt & Mayrhofer Reference Giralt and Mayrhofer1995, as R. confinis); from two localities of New South Wales, Australia (Mayrhofer et al. Reference Mayrhofer, Kantvilas and Ropin1999); and from Georgia, Louisiana and North Carolina, North America (Sheard & Mayrhofer Reference Sheard and Mayrhofer2002).
Additional specimen examined. Brazil: São Paulo: Ponta do Baleeiro; c. 6 km S of São Sebastião, on young, free standing deciduous trees along the beach, 3 m, 23°50′ S, 45°25′ W, 1979, K. Kalb & J. Poelt (hb. Kalb 37185).—Australia: New South Wales: Buckenbowra River Estuary, 7·5 km W Batemans Bay, 1–2 m, 1988, K. Kalb & J. Elix (hb. Kalb 18745, 18746, 18905).
Rinodina guianensis Aptroot
Proc. Kon. Ned. Akad. Wetensch., Ser. C, 90(3): 240 (1987); type: French Guiana, Cayenne, Place des Palmistes in the centre of the town, on Maximiliana (Palmae), March 1985, A. Aptroot (U—holotype).
Rinodina guianensis, ascospores [Kalb s. n. (hb. Kalb 27014)]. A & B, type B ontogeny; C & D mature Pachysporaria-type ascospores, some showing the globular inclusions. Scale = 10 μm.
Ascospore ontogeny and ascospore variability. A, Rinodina brasiliensis (holotype); B, R. guianensis [Kalb s.n. (hb. Kalb-27014)]. Scale = 10 μm.
Thallus crustose, rarely subsquamulose, continuous, smooth, thin, ochraceous, almost entirely isidiate (Fig. 1B). Isidia (20–)30–40(−50) wide × 100–200–(400) μm long, simple to richly branched, concolorous with thallus.
Apothecia sessile, broadly attached, scattered, 0·3–0·5(−0·6) mm diam. Thalline margin concolorous with thallus, thin, becoming isidiate and ±excluded. Disc dark brown, persistently plane. Proper margin visible as a ring inside the thalline margin. Excipulum thallinum up to 90 μm wide. Cortex nearly indistinct. Excipulum propium 10–20 μm laterally, expanded to 50-60 μm above. Hymenium 90–110 μm high. Epihymenium orange-brown. Hypothecium colourless to pale yellowish brown. Asci Lecanora-type. Ascospores Pachysporaria-type, (14–)16–19(–22) × (6·5–)7–10(–12) μm, smooth, walls not ornamented but including globular inclusions surrounding the lumina, without torus, ontogeny type B (Fig. 4A–D, 5B).
Pycnidia and conidia not seen.
Additional information including detailed descriptions may be found in Aptroot (Reference Aptroot1987) and Giralt & Mayrhofer (Reference Giralt and Mayrhofer1995).
Chemistry. No substances could be detected by TLC. Nevertheless a yellowish orange pigment which reacts K+ purple-rose is sometimes present at the base of some apothecia. This reaction was missed byAptroot (Reference Aptroot1987) in the diagnosis of the species. No chemical analyses have been carried out to identify this pigment, but as in R. intermedia it could be skyrin.
Observations. The isidiate thallus with thin, long and richly branched isidia, and the Pachysporaria-type ascospores, including globular inclusions within the spore walls and developed after an ontogeny of type B, are diagnostic for this species.
Rinodina guianensis seems to be a rather variable species, especially concerning the size of the ascospores as well as that of the isidia. Whereas some specimens have ascospores no larger than 19 × 9 μm, in some others they reach 18–22 × 9–12 μm. The same applies to the isidia, which range from rather short and branched to long and richly branched. However these characters are not correlated.
Compared with R. brasiliensis and R. confinis, this species rarely shows a subsquamulose thallus and has a lower hymenium. Furthermore, because of the smaller size of its ascospores, the globular inclusions within the spore wall are not so clearly visible.
A K+ purple-rose medullary reaction is also sometimes present in the related R. intermedia. In this case it is caused by the yellow to orange pigment skyrin (Mayrhofer et al. Reference Mayrhofer, Sheard, Grassler and Elix2001). In the account of R. intermedia given by Mayrhofer et al. (op. cit.), the presence of globular inclusions within the spore walls of this species is not recorded.
Distribution. The distribution of R. guianensis seems to be restricted to the tropics. Hitherto it has been reported from French Guiana (Aptroot Reference Aptroot1987), Brazil and Guatemala (Giralt et al. Reference Giralt, Mayrhofer and Sheard1995).
Additional specimens examined not cited in Giralt et al. (Reference Giralt, Mayrhofer and Sheard1995). Brazil: Goiás: between Jataí and Rio Verde, c. 48 km W of Rio Verde, on deciduous trees at the edge of a cerrado, 780 m, 17°55′ S, 51°10′ W, 1980, K. Kalb & M. Marcelli (hb. Kalb 37186).—Venezuela: Mérida: Distr. Sucre, Hacienda “Los Topes”, San Juanito, a few km ENE of Chiguara, 1500 m, 1989, K. Kalb & A. Morales (hb. Kalb 27014); Chiguara, Finca Antonio Basilio, 900 m, 1989, K. Kalb & A. Morales (hb. Kalb 37187).
The authors are indebted: to the directors and keepers of the following herbaria, GZU, M, S, U and UPS, to J. Sheard for revising the English text and for comments on the manuscript and to P. Agulló and W. Obermayer for improving the plates of figures. The first author thanks the ‘Comissionat per a la Recerca’ (Catalan Government) for support.
