Bulbothrix sensibilis (Stein. & Zahlb.) Hale. Phytologia 28: 481. 1974.

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 : 16-19

Bulbothrix sensibilis (Stein. & Zahlb.) Hale. Phytologia 28: 481. 1974. Figure 15

Parmelia sensibilis Stein. & Zahlb. Afrikanische Flechten (Lichenes), Englers Botanische Jahrbücher für Systematik 60: 522. 1926. [Basionym]

Holotype.

British East Africa, Bei-Bura (Kenia), auf Baumzweigen, leg. Schröder 285 (W!).

Description.

Thallus subirregularly to sublinearly sublaciniate, dusky gray in the herbarium, up to 6.9 cm diam., subcoriaceous, corticolous or ramulicolous; upper cortex 12.5−25.0 µm thick, algal layer 15.0−27.5 µm thick, medulla 87.5−120.0 µm thick, lower cortex 12.5−17.5 µm thick. Laciniae irregularly to occasionally anisotomically dichotomously branched, 1.3-5.2 mm wide, slightly imbricate, becoming crowded at the center, weakly adnate and loosely adpressed, with flat, subrounded to subtruncate apices; margins flat, slightly sinuous to crenate or irregular, entire to slightly incised, ocasionally sublacinulate; axils oval to irregular. Upper cortex smooth and continuous, becoming subrugose with occasional irregular cracks only on older parts; laminal ciliary bulbs absent. Adventitious marginal lacinulae scarce on older parts, short, 0.2-1.2 × 0.1-0.2 mm, plane, simple to irregularly branched; apices truncate; lower side concolor with the lower marginal zone. Maculae weak to distinct, puntiform, laminal, more evident at distal parts of the thallus. Cilia black, without or with simple and short apices, occasionally bent downwards, 0.05-0.20 (-0.30) × ca. 0.03 mm, with emerse bulbate bases 0.05−0.25 mm wide, occasionally withered and reniform, scarce along the margins, becoming frequent at the crenae and axils spaced ca. 0.05−0.15 mm from each other to eventually contiguous, solitary or in small groups becoming absent or scarce at the apices and adjacent parts of the laciniae. Soredia, Isidia, and Pustulae absent. Medulla white. Lower cortex black, with random dark brown spots at the transition to the center, slightly shiny, smooth to subrugose or subvenate, moderately rhizinate. Marginal zone mostly brown, attenuate, ca. 0.5−2.0 mmwide, partially black and indistinct from the center, slightly shiny, smooth to subvenate, weakly rhizinate until the transition to the center. Rhizinae black, sometimes partially dark brown close to the margins, simple to rarely furcate, without basal or displaced bulbs, 0.10-0.30 (-0.40) × ca. 0.05 mm, usually frequent but scarcer at the margins and at the transition to the center, evenly distributed. Apothecia concave to subplane, sessile to adnate, 0.2−4.3 mm diam., laminal, ecoronate; margin and amphitecia initially smooth becoming subrugose, without ornamentations. Disc pale brown, epruinose, imperforate; epithecium 10.0-17.5 µm high; hymenium 30.0−47.5 µm high; subhymenium 20.0−30.0 µm high. Ascospores ellipsoid to oval, (7.0−) 8.0−12.0 (−13.0) × 5.0−7.0 µm; epispore ca. 0.75 µm. Pycnidia frequent, laminal, immersed, with black ostioles. Conidia baciliform to weakly bifusiform 5.0−9.0 × 0.75 µm.

TLC/HPLC: cortical atranorin, medullary salazinic and consalazinic acids (see also Hale 1976).

Distribution.

Asia: Sri Lanka ( Awasthi 1976), India ( Awasthi 1976, Divakar and Upreti 2005), and Thailand ( Pooprang et al. 1999); África: Kenya ( Zahlbruckner 1926, Dodge 1959, Swinscow and Krog 1988), Tanzania ( Swinscow and Krog 1988), Angola, Guinea, Malawi, Zaire, Zambia ( Hale 1976a), Madagascar ( Aptroot 1990), and Rwanda ( Killmann and Fischer 2005, Bock et al. 2007); South America: Venezuela ( Hale 1976a, López-Figueiras 1986), Brazil - State of São Paulo ( Marcelli 1993).

Additional specimens examined.

Venezuela, Táchira, Via Rubio, Brámon, 800-1100 m, leg. M. E. Hale & M. López Figueiras 45727, 24-III-1975 (US). Brazil, São Paulo State, 6 km SW of Jaboticabal, 21°35'S, 48°35'W, on trees in cerradão, leg. A. Fletcher 10138, 03-V-1975 (BM). Idem, Pirassununga, Rawitscher Reserve, Cerrado auf Zweigen, leg. H. Walter & E. Walter Br 58, 30-IX-1965 (M).

Comments.

The holotype of Bulbothrix sensibilis (Fig. 15) consists of a small thallus ca. 6.0 cm in diameter on tree branch, in a reasonable state of preservation, although several parts and apothecia are badly damaged. The material is glued to the card voucher, and it was necessary to free some laciniae for observation of the lower cortex. There are apothecia containing ascospores in good condition and there are several pycnidia with conidia.

Steiner and Zahlbruckner ( Zahlbruckner 1926) described the species as having no cilia, but mentioning of what they interpreted as a constant presence of parasites with inflated bases or converted into bulbs ("non rare planta parasitica inclusis, basin ve rsus semel vel bis bulbiformiter inflatis vel bulbum tantum formantibus"). The authors also noted the occurrence of brown patches in certain parts of the center of the thallus lower cortex, and not just at the margins. Dodge (1959) commented on the tendency of laciniae in the central parts of the thalli to became with a more wrinkled and broken surface. The author also did not perceive the bulbate cilia, though he did mention something like small papillate rhizines along the margins. Interestingly, he described the apothecia as perforate, what was not found on the material examined here. Awasthi (1976) was the first author to describe bulbate cilia for the species. The characteristics he described are in accordance with the type material, only his measures of the laciniae being even wider (2.0 to 6.0 mm). The ascospore descriptions and measurements of the specimens studied by Dodge (1959), Awasthi (1976), Swinscow and Krog (1988) and Divakar and Upreti (2005) are all in accordance with the type of material of Bulbothrix sensibilis .

The material atributted by Marcelli (1993) to Bulbothrix sensibilis , described as emaculate with a overall black lower cortex, sparse rhizines sparse and ascospores 12.6−14.4 × 7.2−8.1 µm are in fact weakly, sparsely maculate specimens of Bulbothrix meizospora with laciniae and ascospore of minimum dimensions found in the species, but not below those considered normal.

Hale (1976a) attributed examined specimens from several African countries and Venezuela to Bulbothrix sensiblis , with a first citation of the species for the Americas. Overall, the material described is in accordance with the type material. However, in two keys ( Hale and Kurokawa 1964, Hale 1976a) were cited ascospores sizes as 7.0−9.0 µm long, much smaller than the size 7.0−18.0 × 5.0−12.0 µm that Hale mentioned in the description of the species in his monograph ( Hale 1976a).

Hale (1976a) cited in his key subirregular laciniae for Bulbothrix meizospora and sublinear for Bulbothrix sensibilis , the opposite of what is in his descriptions, where Bulbothrix meizospora is the species described as having sublinear laciniae, not Bulbothrix sensibilis . Although he used different widths in the key laciniae as to differences for separate them, he also described the same size for both. Jungbluth et al. (2008) discussed in the description of Bulbothrix vainioi on the possible identity of the South American material of Bulbothrix sensibilis seen by Hale (1976a). The authors believed in the hypothesis of the involvement of two taxa, one composed of African and Indian specimens with ascospores less than 12.0 µm long corresponding to the true Bulbothrix sensibilis , and the other composed of the South American specimens with ascospores larger than 12.0 µm long that they described as Bulbothrix vainioi .

It is possible that Hale (1976a) may have been confused when typing measurements closer to those of the ascospores of Bulbothrix meizospora in the description of Bulbothrix sensibilis , since the differences he used in the key are exactly as seen here. Another hypothesis is that Hale may have mistaken the material of Venezuela with Bulbothrix sensibilis due to the similarity between the African specimens with his South American specimen. As found by analyzing material of Bulbothrix vainioi and Bulbothrix meizospora , even differences of cilia cited in the comments under Bulbothrix vainioi are minimal and usually found in the same species, even in a same specimen.

Bulbothrix hypocraea (Vain.) Halediffers by being more evidently maculate than Bulbothrix sensibilis , by the pale brown lower cortex with slighly darker margins, and by the brown rhizines with dark basal or displaced bulbs. Hale (1976a) noted that although the african-american pattern of distribution, Bulbothrix sensibilis was a much rarer species, believing that Bulbothrix sensibilis should either be or resemble the parental form of Bulbothrix tabacina (Mont. & Bosch) Hale. In turn, Bulbothrix tabacina (L! lectotype, duplicate at PC!) differs by the formation of laminal isidia, a uniformly black lower cortex, and by the averagely larger ascospores 9.0−16.0 × 5.0−8.0 µm.

Bulbothrix bulbochaeta (Hale) Hale (LWG! holotype, US! isotype) differs by the narrower laciniae ca. 1.0−2.5 mm wide, the branched cilia and rhizines, the constant presence of laminal ciliary bulbs, the coronate apothecia containing very small and rounded ascospores 4.0−6.0 × 3.0−4.0 µm and by the absence of medullary substances.

Bulbothrix linteolocarpa Marcelli was compared to Bulbothrix sensibilis by Marcelli (1993), and differs by the linear, narrower and truncated laciniae 0.2−0.6 (−0.8) mm wide, the brown lower cortex, the very adnate, distended plane apothecia containing larger ascospores 12.0−16.0 × 6.0−8.0 µm, and by the frequent cilia with smaller bulbs (similar in size and aspect to those found in Bulbothrix species containing gyrophoric acid) and longer apices.

Bulbothrix meizospora (Steiner & Zahlbruckner) Hale differs by the laciniae usually more irregularly branched and with rounded apices, and by the always larger ascospores, measuring 12.0−22.0 × 8.0−12.0 µm. Comparatively, thalli of Bulbothrix sensibilis are also more evidently maculate.