Bulbothrix enormis (Hale) Krog. The Lichenologist 25(3): 299. 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 : 6-9

Bulbothrix enormis (Hale) Krog. The Lichenologist 25(3): 299. 1993. Figure 3

Parmelia enormis Hale. Phytologia23(4): 344. 1972. [Basionym]

Parmelina enormis (Hale) Hale. Phytologia 28: 482. 1974. [Synonym]

Holotype.

Zambia, Zambia Rest House area, Nyika Plateau, 7600 ft., on granite rocks, M. Jellicoe s.n., VII-1968 (BM!, isotypes at TNS n.v. and US!).

Description.

Thallus sublinearly to subirregularly sublaciniate, gray with dusky green distal parts in herbarium, up to 24.1 cm diam., coriaceous, saxicolous; upper cortex 15.0−22.5 µm thick, algal layer 52.5−80.0 µm thick, medulla 120.0−150.0 µm thick, lower cortex 15.0−25.0 µm thick. Laciniae isotomically or anisotomically to irregularly dichotomously branched, (1.3−) 3.2-6.0 (−7.8) mm wide, imbricate to crowded, slightly to not adnate and loose, occasionally almost subcanaliculate, with involute to revolute or sometimes plane, subrounded to subtruncate apices; margins plane to subundulate or slightly involute, smooth and sinuous to occasionally subcrenate, entire, rarely little sublacinulate; axils oval. Upper surface smooth and continuous, rarely with some random irregular cracks; laminal ciliary bulbs absent. Adventitious marginal lacinulae scarce on random parts, short, 0.5-1.7 × 0.3-1.1 mm, usually involute, simple or sometimes irregularly branched; apices truncate to subtruncate; lower side concolorous to the lower marginal zone. Maculae absent. Cilia black to dark brown, with simple to partially double or furcate apices, occasionally bent downwards, 0.10-1.20 (-1.80) × ca. 0.05 (−0.10) mm, with semi-immerse to emerse bulbate bases 0.05-0.20 (-0.35) mm wide or partially not bulbate, sometimes disposed on a distinct black line, frequent to abundant throughout the margins, in small groups in the axils and adjacent parts spaced 0.10−0.40 mm from each other, becoming absent or scarce at the apices of the laciniae and adjacent parts. Soredia, Isidia and Pustulae absent. Medulla usually white, but pinkish in some random parts and below the hymenial discs. Lower surface pale brown, occasionally with random small dark brown or black spots, shiny, smooth, moderate to densely rhizinate. Marginal zone brown, indistinct from the center or sometimes interrupted by blackish spots, shiny, smooth, weakly papillate, gradually becoming rhizinate following the center. Rhizinae black to variably brown, occasionally whitish or with withish apices, simple to occasionally furcate or irregularly branched, without bulbate bases or with subtle basal or displaced bulbs, 0.20-1.80 (−2.30) × 0.05-0.10 mm, frequent to abundant, evenly distributed. Apothecia subconcave to urceolate or occasionally plane, becoming folded when old, adnate to substipiate, 1.1-10.0 mm diam., laminal to submarginal, ecoronate; margin smooth to subcrenate and fissured; amphithecium smooth, without ornamentations. Disc brown to dark brown, epruinose, imperforate; epithecium 7.5-17.5 µm high; hymenium 20.0−55.0 µm high; subhymenium 12.5−22.5 µm high. Ascospores ellipsoid to oval or subrounded, 7.0-11.5 × 5.0-7.0 mm; epispore (0.5−) 1.0−1.5 mm thick. Pycnidia laminal to submarginal, frequent, immerse, with brown or black ostioles. Conidia baciliform to weakly or distinct bifusiform 5.0−8.0 × 0.75 µm.

TLC/HPLC: cortical atranorin and chlororatranorin, medullary salazinic and consalazinic acids (see also Hale 1972, 1976b).

Distribution.

Africa: Zambia ( Hale 1972, 1976b, Krog 1993), Malawi, and Tanzania ( Krog 1993).

Additional specimen examined.

Zambia, Zambia Rest House area, Nyika Plateau, leg. M. Jellicoe s.n., IV-1969 (FH).

Comments.

The holotype consists of a large specimen more than 20 cm in diameter, glued to board, in excellent condition and containing several apothecia and pyc nidia. There are some loose fragments from 3 to 10 cm diam., allowing vizualization of the lower cortex details. The isotype from US consists of several loose fragments such as those with the holotype, also in good condition, with mature apothecia and pycnidia. There are no remains of the rocky substrate of where the materials were collected, indicating that the thalli were not strongly adhered to the substrate.

Originally, Hale (1972) did not notice the presence of bulbs in the cilia of this species, and recombined it ( Hale 1974) into Parmelina Hale without any comment. Hale (1972) first commented that the presence of cilia located in the axils would situate it in Section Imbricaria , even though he said that the species superficially resembled a Hypotrachyna species due the shape of the laciniae, what he again emphasized in the genus monograph ( Hale 1976b). Although the general appearance of the thalli indeed resembles a large specimen of Hypotrachyna as he said, the presence of marginal cilia and the simple rhizines easily differentiate Bulbothrix enormis from this other genus.

Most of the cilia seen in the specimens studied are bulbate, but some of them are not, even including some of the largest cilia. However, the bulbs have the typical anatomical structure of Bulbothrix species, with an oily substance and idioblasts cells ( Hale 1975, Feuerer and Marth 1997, Benatti 2011). They vary from the more typical globose aspect to an oval shape, stretching following the growth and detachment of the apices. Some have slightly extended bases, perhaps an early stage of development of the cavity.

While Hale (1972, 1976b) mentioned an overall brown lower cortex, it should be noticed that although this is the predominant color, darker or even blackish spots may occur, occasional and randomly scattered (these were not seen in the FH specimen). The rhizines may also vary from paler to darker than the cortex, or be blackish.

Krog (1993) realized that this species did not fit well in the concept of the genus Parmelina due to the configuration of the lobes, and recombined it into Bulbothrix , having confirmed the presence of marginal bulbate cilia in the holotype and other specimens. The author realized that her material from Southern Africa fitted the description of Parmelina enormis , and she observed bulbate cilia in this species.

Bulbothrix hypocraea (Vainio) Hale and Bulbothrix setschwanensis (Zahlbruckner) Hale were compared to Bulbothrix enormis by Krog (1993) because they shared a pale brown lower cortex, simple rhizines and medullary salazinic acid. The author distinguished these species by their less robust thalli, usually adnate on bark, with crenate lobes with a more or less irregular pattern of branching. Besides the differences mentioned by Krog (1993), Bulbothrix hypocraea also has narrower laciniae ca. 1.5−4.0 mm wide, an evidently maculate upper cortex, overall clearly bulbate cilia with short apices that appear solitary at the crenae and axils of the laciniae. Bulbothrix setschwanensis also differs by the narrower laciniae (ca. 1.0−3.5 mm wide), cilia in crenae or axilary with overall globose, evident bulbate bases and short apices, and by the larger ascospores (12.0−19.0 × 7.0−10.0 µm).

Bulbothrix haleana Sérusiaux (LG!, US!) differs by the thallus aspect, with narrow subirregular laciniae 1.0−3.5 mm wide, the overall globose and always evidently bulbate cilia with shorter apices, and by the smaller ascospores 5.0−9.0 × 4.0−7.0 µm. Further it contains norstictic acid, rather than salazinic acid as stated in the original description ( Benatti 2012).

Another relatively similar species, Bulbothrix meizospora (Nylander) Hale, also differs by the narrower laciniae (ca. 1.5−4.0 mm wide), larger ascospores (12.5−22.0 × 9.0−14.0 µm) and a black lower cortex with brown margins.

Hale (1972) compared Bulbothrix enormis also to Parmelina usambarensis Steiner & Zahlbruckner [= Pseudoparmelia usambarensis (Steiner & Zahlbruckner) Krog & Swinscow (REN!, lectotype)], another similar African saxicolous species, but this species forms isidia, has a black lower cortex, and although he cited eciliate margins, it does have marginal cilia, just not in abundance.