Bulbothrix linteolocarpa Marcelli. Acta Botanica Brasilica 7(2): 42. 1993.

Benatti, Michel N., 2012, A review of the genus Bulbothrix Hale: the species with medullary salazinic acid lacking vegetative propagules, MycoKeys 5, pp. 1-30 : 12-13

Bulbothrix linteolocarpa Marcelli. Acta Botanica Brasilica 7(2): 42. 1993. Figure 10

Holotype.

Brazil, Mato Grosso State, between Jaciara and São Vicente, km 313 of BR-364 highway, ca. 100 km ESE of Cuiabá, cerradão (savannah), on tree trunk, leg. Marcelli 8446, 2-VII-1980 (SP!).

Description.

Thallus sublinear laciniate, dusky gray in the herbarium, up to 2.6 cm diam., subcoriaceous, corticolous; upper cortex 20.0−30.0 µm thick, algal layer 55.0−75.0 µm thick, medulla 25.0−35.5 µm thick, lower cortex 10.0−15.0 µm thick. Laciniae irregularly to anisotomically dichotomously branched, 0.2-0.6 (-0.8) mm wide, contiguous to occasionally slightly imbricate, adnate and adpressed, with flat, truncate apices; margins flat, smooth to sinuous or subirregular, entire to slightly incised and rarelly sublacinulate; axils oval to irregular. Upper cortex continuous, smooth to subrugose; laminal ciliary bulbs absent. Adventitious marginal lacinulae scarce on older parts, short, 0.1-0.6 × 0.05-0.20 mm, plane, simple; apices truncate; lower side concolor to the lower marginal zone. Maculae absent. Cilia black to brown, with simple to partially furcate apices, often bent downwards, 0.05-0.45 × ca. 0.03 mm, with semi- immerse to emerse bulbate bases ca. 0.05-0.10 mm wide, frequent along the margins, spaced 0.5-0.10 mm from each other rarely becoming contiguous at the axils, usually absent or scarce on the apices of the laciniae. Soredia, Isidia and Pustulae absent. Medulla white. Lower surface pale brown, shiny, smooth, weakly papillate, moderately rhizinate. Marginal zone pale brown, slightly darker than the center, shiny, attenuate, 0.5-1.0 mm wide, smooth, weakly papillate, sligthly rhizinate. Rhizinae light to dark brown or almost blackish, simple to occasionally furcate or irregularly branched, often with dark basal or displaced bulbs, 0.05-0.60 × ca. 0.03-0.05 mm, frequent, becoming scarce at some parts, partially agglutinated, evenly distributed. Apothecia subconcave, becoming plane or convex, stretching over the laciniae while maturing, adnate, 0.3−3.4 mm diam., laminal, ecoronate; margin smooth to incised and subcrenate; amphitecium smooth, without ornamentations. Disc brown, epruinose, imperforate; epithecium 12.5-20.0 mm high; hymenium 37.5−45.0 µm high; subhymenium 15.0−20.0 µm high. Ascospores ellipsoid to oval, (9.0−) 10.0−16.0 × 6,5−8,0 µm; epispore ca. 1.0 µm. Pycnidia not found.

TLC/HPLC: cortical atranorin and chloroatranorin, medullary salazinic, consalazinic and secalonic A acids (label from J. A. Elix with the holotype, 19-VII-1995).

Distribution.

South America. Brazil - States of Mato Grosso and São Paulo ( Marcelli 1993).

Additional specimens examined.

Brazil, Mato Grosso State, between Jaciara and São Vicente, ca. 100 km ESSE of Cuiabá, 750 m alt., on thin twig at the cerrado (savannah), leg. M.P. Marcelli 8445, 02-VII-1980 (SP). Idem, São Paulo State, Moji-Guaçu Municipality, Fazenda Campininha, Estação Biológica de Moji-Guaçu, illuminated and dry cerradão (savannah), on thin twig, leg. M.P. Marcelli 15812, 07-XII-1976 (SP). Idem, Santa Rita do Passa Quatro Municipality, fazenda Vassununga, km 259 of the Anhanguera Highway, 760 m alt., transition from cerrado to cerradão (savannah), trees with signs of old burnings, on tree thin twig, leg. M.P. Marcelli & SB. L. Morretes 15626, 23-VI-1978 (SP). Idem, São Carlos Municipality, Campus of the Universidade Federal de São Carlos - UFSCar, cerrado (savannah), on a wooden fence near a firebreak, 22°1'S, 47°53'W, alt. 855 m, on Eucalyptus sp. trunk, leg. G. G. Batista & M. N. Benatti 115B, 04-IX-2006 (HUFSCar).

Comments.

The holotype (Fig. 10) consists of small thalli about 2.5 cm diameter, in good condition, on tree bark and over a crustose lichen with blackened perithecia. It was necessary to detach some laciniae for proper observation of the lower cortex. The upper cortex is emaculate, and there are several apothecia with ascospores in different stages of maturation.

A peculiar anatomical characteristic is that the algal layer is always thicker than the medulla in all examined material of Bulbothrix linteolocarpa , and usually appears to be in the middle of the medulla, separating it in two portions, instead of being situated in its upper portion just below the cortex.

Some of the specimens analysed by Marcelli (1993) were confirmed to have wider laciniae (1.0−2.5 mm), a darker brown lower cortex, cilia with very globose basal bulbs and longer apices, and simple rhizines simply without basals bulbs. These specimens, that the author suspected to belong to a similar but different taxon, are actually Bulbothrix continua (Lynge) Hale.

Bulbothrix continua (Lynge) Hale is the closest species to Bulbothrix linteolocarpa in overall characteristics. However, Bulbothrix linteolocarpa has much narrower laciniae than Bulbothrix continua (0.2−0.5 against 1.0−2.5 mm), cilia with smaller, less globose bulbate bases (0.05−0.10 mm vs. 0.05−0.25 mm), and always with apices that are also partially furcate, a darker lower cortex, and less abundant, more variably branched rhizines.

Marcelli (1993) compared Bulbothrix linteolocarpa to Bulbothrix hypocraea (Vainio) Hale and to Bulbothrix sensibilis (Steiner & Zahlbruckner) Hale. As to Bulbothrix hypocraea , see under that species. Bulbothrix sensibilis has larger laciniae (ca. 1.0−4.0 mm larg.) that are often imbricated or crowded, cilia without apices or with simple short apices, normally restricted to the crenae and axils of the laciniae, concave to urceolate apothecia, a black lower cortex with brown margins, and averagely smaller, often subrounded ascospores (7.0−12.0 × 5.0−7.0 µm).

An apparently common species on cerrado (savannah) areas, Bulbothrix linteolocarpa was mentioned by Mistry (1998) in an article on bioindicators of fires.