Bulbothrix regnelliana Jungbluth, Marcelli & Elix. Mycotaxon 104: 58. 2008.

Benatti, Michel N., 2012, A review of the genus Bulbothrix Hale: the species with medullary norstictic or protocetraric acids, MycoKeys 2, pp. 1-28 : 9-12

Bulbothrix regnelliana Jungbluth, Marcelli & Elix. Mycotaxon 104: 58. 2008. Figures 9-10

Holotype.

Brazil, São Paulo State, São José do Rio Preto Municipality, 20°49'S, 49°22'W, 489 m alt., on palm tree trunk in open field, D.F. Peralta 2325, 09-IV-2004 (SP!, isotype B!).

Description.

Thallus subirregular sublaciniate, dusky gray in herbarium, fragments up to 4.6 cm diam., subcoriaceous, corticicolous; upper cortex 12.5−17.5 µm thick, algal layer 20.0−25.0 µm thick, medulla 75.0−92.5 µm thick, lower cortex 12.5−17.5 µm thick. Laciniae irregularly ramified to occasionally anisotomically dichotomously branched, (1.0−) 1.6-2.5 (−3.7) mm wide, imbricate becoming crowded in the center, weakly adnate to loose and ascending, with flat to involute, subrotund apices, the margins flat to involute frequently giving the laciniae a subcanaliculate aspect, crenate to subirregular, entire to irregularly incised, not lacinulate, the axils oval to irregular, upper cortex continuous with rare, random irregular fissures, smooth, laminal ciliary bulbs absent. Lacinulae absent, not even marginal adventitious ones present. Maculae absent. Cilia black, apices frequently absent to less commonly simple and short, 0.05-0.25 × ca. 0.03 mm, with emerse bulbate bases (0.05−) 0.10-0.35 mm wide, frequently along the margins in the crenulations and axils of the laciniae spaced 0.05−0.10 mm from each other, occasionally becoming contiguous, solitary or in small groups, becoming absent or scarce at the apices of the laciniae and adjacent parts. Soredia, pustulae and isidia absent. Medulla white. Lower cortex pale brown to brown, sometimes appearing to be darker in some parts due to groups of dark rhizinae, opaque, rugose, moderately to densely rhizinate. Marginal zone brown to pale brown, not distinct from the center, opaque to slightly shiny, rugose or weakly venate, papillate, becoming slightly rhizinate towards the center. Rhizinae brown to pale brown, occasionally dark, black or with whitish apices on random parts, simple or rarely irregularly branched, generally with blackish bulbate bases of dislocate bulbs, 0.10-0.50 (−0.80) × 0.03-0.10 mm, frequent to abundant, commonly agglutinated, evenly distributed. Apothecia concave to urceolate, adnate to substipitate, 0.3-7.5 mm diam., laminal, margins crenate becoming deeply crenate, fissured and folded as they age, coronate (bulbs irregularly appearing in the crenulations), amphithecia smooth to rugose without ornamentations. Disc brown, epruinose, imperforate, epithecium 10.0-15.0 mm high, hymenium 25.0−40.0 µm high, subhymenium 20.0−30.0 µm high. Ascospores ellipsoid to oval, (7.0−) 8.0−12.0 (−14.0) × 4.0−7.0 (−8.0) µm, epispore ca. 1.0 µm. Pycnidia frequent, submarginal to subapical or sometimes laminal, immerse, with black ostioles; conidia bacilliform to weakly or distinctly bifusiform, (4.0−) 5.0−7.5 (−9.0) × 1.0 µm.

Spot tests.

upper cortex K+ yellow, UV-; medulla K+ yellow→orange or light red, C-, KC-, P+ orange, UV-.

TLC/HPLC.

cortical atranorin, medullary norstictic acid and four unknown substances (see also Jungbluth 2006, Jungbluth et al. 2008).

Distribution.

South America. Brazil: São Paulo ( Jungbluth 2006 as Bulbothrix subcoronata , Jungbluth et al. 2008). Here is reported for Paraguay, Argentina, and Brazilian States of Minas Gerais and Rio Grande do Sul.

Additional specimens examined.

Paraguay, Paraguarí, Parque Nacional Ybycuí, along road/trail to Salto Mbocaruzú on Rio Corrientes, ca. 200 m, ca. 26°05'S, 56°53'W, dry Forest and extensive sandstone outcrops in cerrado, leg. W.R. Buck 12006a, 6-X-1984 (NY). Argentina, Corrientes, Depto. Capital, 500 m de tuta 12, camino a Santa Ana, em quebranchal, leg. L. Ferraro 1287, 05-VI-1978 (US). Idem, Depto. Esquina, 10 km S de ruta 126, camino de Tres Bocas a Paso Yunque, leg. A. Krapovickas 28074, 13-III-1975 (US). Idem, Missiones, San Ignacio, pastoreo Grande, em bosque despejado, sobre ramas de Astronium balansae y Helietta cuspidata , 290 m, leg. J. E. Montes 10060 pr. p., 20-III-1956 (US). Brasil, Minas Gerais State, Catas Altas Municipality, Serra do Caraça, Parque Natural do Caraça, on tree trunk at the foot of the Morro do Calvário at the side of the hotel, leg. M.P. Marcelli & A.E. Luchi 29654, 10-XI-1995 (SP). Idem, São Paulo State, Serra Negra Municipality, Alto da Serra, near the television tower, on small tree twig on the edge of the illuminated and humid mountainous forest, leg. M.P. Marcelli, O. Yano & A.B. Carvalho 22703, 05-IV-1993 (SP). Idem, Santa Rita do passa Quatro Municipality, Vassununga farm, km 259 of the Anhanguera highway, 760 m alt., transition from cerrado to cerradão, on thin twig, leg. M.P. Marcelli & B. L. Morretes 16057, 27-IX-1978 (SP). Idem, Rio Grande do Sul State, Esmeralda Municipality, Estação Ecológica Aracuri, on cortex of Schinus polygamus , 920 m alt. leg. M. Fleig 1830, 12-XII-1982 (ICN).

Comments.

The holotype (Fig. 9) and the isotype (Fig. 10) consist of two fragments in good condition, free of substrate, not glued to the voucher card, which mad e the observation of the characters of the lower cortex possible. Both have numerous apothecia, although it is difficult to find ascospores (hymenia often without asci).

Several authors determined specimens of Bulbothrix regnelliana Jungbluth, Marcelli & Elix as Bulbothrix subcoronata ( Müller Argoviensis) Hale or Bulbothrix viatica Spielmann & Marcelli (e.g. Eliasaro 2001, Ribeiro 1998). These three species form a closely related group, in which the species are distinguished mainly by the color of the lower cortex, the size of ascospores and the presence or absence of laminal ciliary bulbs.

Although Jungbluth (2006) made an attempt to relate the shape of apothecia with the size of the ascospores in order to separate the species with norstictic acid, a close examination of the material of Bulbothrix subcoronata , Bulbothrix regnelliana and Bulbothrix viatica demonstrated that this is not a reliable character for the species separation due to character overlap. In fact there are specimens interpreted as Bulbothrix subcoronata with ascospores ca. 7.0−12.0 mm long ( Hale 1976, Fleig 1985) and others with ascospores 10.0−20.0 mm long (Marcelli1993, Eliasaro 2001, Ribeiro 1998).

Based on the color of the lower cortex and the ascospore size, the material examined by Hale (1976), which was described as Bulbothrix subcoronata , should probably belong to Bulbothrix regnelliana , as assumed by Jungbluth et al. (2008). It is also possible that the material examined by Fleig (1985), described with ascospores ≤ 10 mm, belongs to Bulbothrix regnelliana .

In fact, the type specimen of Bulbothrix subcoronata has a shiny black lower cortex with a well defined brown marginal zone, and a single, coronate apothecium, containing very small ascospores (5.0−7.5 × 4.0−5.5 µm). Bulbothrix subcoronata is further distinguished from Bulbothrix regnelliana by the smaller width of the laciniae (ca. 0.5−1.0 mm), the more frequent marginal cilia often with simple apices, and the retrorse rhizinae on the amphithecium of the apothecia.

Bulbothrix viatica and Bulbothrix regnelliana have several characteristics in common, which lead to the hypothesis that they were synonymous. Some specimens with overlapping characters were found; this concerned the absence of laminal ciliary bulbs, marginal cilia with and without apex, a brown lower cortex with small dark spots and ascospores 10.0-14.0 µm long. However, when analyzing the characteristics of the specimens, verifying the collection sites and comparing the material side by side, a correlation of small features was noticed that include the total absence of laminal ciliar bulbs, an emaculate upper cortex, cilia often without apices, a strictly brown lower cortex and ascospores usually ≤ 12 µm long in Bulbothrix regnelliana . which are apparently constant and related to the possible geographic distribution of the species. We therefore decided not to put them into synonymy. The region of the Tropic of Capricorn seems to represent the northern limit of distribution for Bulbothrix regnelliana , while the latitude of Rio Grande do Sul State in Brazil may represent the southern limit of distribution for Bulbothrix viatica . Thus, there is a common area of occurrence for both. Also some very few specimens mentioned ( Ribeiro 1998) with large ascospores, that are know only from the north of Minas Gerais State, also in Brazil, that might represent an undescribed taxa maybe overlapping with the distribution of Bulbothrix viatica .

Bulbothrix ventricosa (Hale & Kurokawa) Hale differs from Bulbothrix regnelliana by having the same characteristics as Bulbothrix viatica , and the presence of maculae as well as laminal isidia. The coloration of the lower cortex shows an even more frequent mixture variation (i.e., much more varied mixes of black and brown tones) in Bulbothrix ventricosa than in Bulbothrix viatica .

Bulbothrix hypocraea (Vainio) Hale differs by the densely maculate upper cortex, marginal cilia with simple apices, ecoronate apothecia and medullary salazinic acid.

Bulbothrix continua (Lynge) Hale differs by the sublinear and dichotomous laciniae, abundant and contiguous bulbate cilia with long apices bent downwards, rhizinae without basal bulbs, ecoronate apothecia and medullary salazinic acid. Bulbothrix lintelocarpa Marcelli is similar to Bulbothrix continua , but has narrower laciniae (0.3−0.5 mm wide), simple to branched rhizinae, flat apothecia straining over the laciniae, and slightly larger ascospores 10.0−15.0 × 6.5−8.0 µm.

Bulbothrix setschwanensis (Zahlbruckner) Hale differs by the frequent marginal cilia usually with simple apices, rhizinae without basal bulbs, ecoronate apothecia with larger ascospores 12.0-19.0 µm long, and medullary salazinic acid.

Relicina subabstrusa (Gyelnik) Hale ( Hale 1975, Elix 1996) differs by having cortical usnic acid, laciniae more linear, cilia regularly with apices and not only restricted to the axils, and apothecia with bulbs or retrorse rhizinae on the amphithecium (as in Bulbothrix subcoronata ) containing smaller ascospores (7.0-8.0 × 4.0−5.0 µm).