Bactrospora A.Massal.
=MELAMPILIDIUM Stirt., 1875
Type : Bactrospora dryina (Ach.) A.Massal. [=Lichen dryinus Ach.]
Type : Melampilidium amphorodes (Stirt.) Stirt. [=Lecidea amphorodes Stirt.]
Description : Thallus crustose, continuous, occasionally fissured or areolate, whitish or greyish, sometimes with a yellowish or greenish tinge, smooth, endo- to episubstratal, prothallus usually indistinct; lacking isidia or soralia. Photobiont green, Trentepohlia. Ascomata apothecia, solitary, black, epruinose, immersed to sessile. Margins variously developed, ±excluded to prominent. Exciple poorly to well-developed, laterally dark-brown to carbonaceous, K+ green-brown, of conglutinate, thick-walled hyphae. Hymenium colourless, without hymenial strands of excipular tissue intruding between the paraphysoids (ascostromata multiascal, monocarpocentral, sensu Tehler 1990: 2465). Subhymenium pale- to dark-brown, rarely colourless. Paraphysoids dichotomously branched, not or rarely anastomosing, loosely interlaced in hymenium, to 2.5 μm diam., much longer than asci. Asci bitunicate, fissitunicate, cylindrical with a distinct stipe and foot-like base, easily separated from ascogenous hyphae and easily fragmented, with (4–)6–8 subparallel ascospores, often appearing multi-spored. Exoascus thin and birefringent. Endoascus slightly hemiamyloid, not layered. Apical apparatus a conspicuous ring-structure (I+ pink, IKI+ blue) around basal part of small oculus, without apical nasse (Bactrospora -type – Torrente & Egea 1989b; Egea & Torrente 1994: 20). Ascospores cylindrical to acicular, colourless, (1–)3-pluriseptate to occasionally muriform; easily broken and separating into pluricellular or unicellular fragments. Four spore-types recognised (1) Dryina -type: Acicular with even surface when young, soon fragmenting in ascus into unicellular or paucicellular segments; cells usually longer than wider or ±roundish; (2) Patellarioides -type: Acicular, with even surface or slightly constricted centrally, fragmenting into pluricellular segments outside asci; cells longer than wide; (3) Jenickii -type: Acicular to cylindrical, with roundish ends and uniformly narrowing to centre (biclavate), constricted at one or more septa, scarcely fragmenting into pluricellular segments in or outside asci; usually longer than wide; (4) Homalotropa -type: Cylindrical, constricted at one or more septa, fragmenting into pluricellular segments outside asci; cells usually wider than long. Conidiomata pycnidia, punctiform, immersed or subimmersed in thallus or substratum, globose to ±cylindrical, unilocular to secondarily plurilocular, walls dark-brown or carbonaceous in upper parts, pale-brown or colourless internally, K+ green-brown. Conidia variable; bacillar, straight or slightly curved (4–9 × 1 μm); or filiform and curved (8–17 × 1 μm); occasionally oblong (3–5 × 1.5 μm) or filiform and straight or slightly curved.
Key
Bactrospora, included in the family Roccellaceae (Eriksson et al. 2004; Pennycook & Galloway 2004) is closely related to the genera Opegrapha and Lecanactis. Comparisons between the three genera are discussed by Egea & Torrente (1993a: 216) in their monograph of the genus. Species of Bactrospora are widely distributed in tropical, subtropical and temperate regions of both Northern and Southern hemispheres; 24 taxa are known worldwide (Egea & Torrente 1993a, 1995; Kirk et al. 2001; Egea et al. 2004a; Kantvilas 2004j) and three are present in New Zealand. The type of Platygrapha atrata Stirt. (see Flora 1985: 521 – as Schismatomma atratum (Stirt.) Zahlbr.) is also probably referable to Bactrospora (Egea pers. comm. in Tehler 1993c: 29).
