Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Life habit: lichenized Thallus: crustose, immersed or +superficial, thin, continuous, scurfy, uniform or +rimose or areolate; prothallus: usually indistinct surface: smooth, white or pale gray, sometimes with a yellowish or greenish tinge, lacking soredia and isidia anatomy: internally appearing +paraplectenchymatous, ecorticate and without a well-differentiated medulla photobiont: primary one a trentepohlioid green alga, secondary one absent Ascomata: apothecioid, solitary, immersed to sessile, often constricted at base disc: black or black-brown, epruinose, expanded margin: variously developed, +excluded to prominent and persistent, lacking a thalline portion, sometimes with small triangular lobes giving the ascomata a denticulate-stellate appearance exciple: poorly to well developed, laterally dark brown to carbonaceous, dark red-brown at outer edge, paler within, pigment K+ blackish olive; composed of conglutinate, thick-walled hyphae, closed or open at the bottom and extending down towards the medulla or substrate, with strongly gelatinized hyphal walls (individual hyphae not easily discernible), externally with crystals on the surface pseudoepithecium: pale to dark red-brown, reticulate, composed of irregularly shaped, agglutinate, free or strongly branched and anastomosing paraphysoid tips hymenium: hyaline, I- or I+ blue, multiascal, without strands of excipular tissue (monocarpocentral sensu Tehler 1990: 2465); paraphysoids: sparsely and dichotomously branched, with little or no anastomosing and loosely interlaced in the hymenium, up to 2(-2.5) µm wide, much longer than the asci, with constricted septa in young ascomata (e.g., B. dryina), without swollen apical cells, +dark brown at the outer part of the cell wall sub-hymenium: (sensu Letrouit-Galinou and Bellemére, 1990): pale to dark brown, rarely hyaline; hypothecium: hyaline asci: narrowly clavate to cylindrical, with a distinct stipe and foot-like base not or slightly widened, easily separated from ascogenous hyphae and often broken; bitunicate of the fissitunicate type, with a narrow apex K/I+ pale blue, with an apical dome penetrated by a small ocular chamber surrounded at the base by a small I+ pink, K/I+ dark blue, ring-like zone, without an apical nasse, with a thin and refringent exoascus, with a slightly hemi-amyloid (K/I) outer and inner endoascus, not layered, 8-spored (sometimes appearing multispored due to fragmentation of spores within the asci) ascospores: hyaline at all stages, (1-)3-45-septate, acicular, cylindrical or biclavate, 20-175 x 1.5-13(-14) µm, often easily fragmenting into part spores (spherical, cuboid or rectangular), without gelatinous sheath, with thin, unswollen walls at the septa Conidiomata: pycnidial, punctiform, immersed to subimmersed in the thallus or substrate, globose to +cylindrical, unilocular to secondarily plurilocular, with walls dark brown or carbonaceous at the upper part and pale brown or hyaline in the inner part and K+ green-black conidia: simple, composed of several types depending on the species: 1) bacilliform and straight or slightly curved (4-9 x 1 µm), 2) filiform and curved (817 x 1 µm) or +straight, or occasionally 3) long-ellipsoid (3-5 x 1.5 µm), with +round ends, without macroconidia Spot tests: thallus and medulla K-, C-, KC-, P- Secondary metabolites: none detected or occasionally unknown substances present Substrate: usually in dry recesses in +rough bark of medium-aged to old, broad-leaved trees or shrubs, normally near the base in humid and shaded places, sometimes on +vertical or overhanging, siliceous rock faces exposed to the north or northwest Geography: tropical to temperate, in both hemispheres, most prolific in the neotropics, mostly confined to lowland, often coastal areas in Europe, Asia, northern Africa, North America, Central America, South America and Australasia. Notes: Bactrospora is characterized by the following characters: thallus with trentepohlioid photobiont, ascomata multiascal (sensu Tehler 1990), no differentitaion of a parathecial apparatus (sensu Letrouit-Galinou and Bellemère, 1989: 213; Torrente and Egea 1989: 47), hamathecia paraphysoidal, asci bitunicate with a fissitunicate dehiscence and with a hemi-amyloid endoascus and trans-septate ascospores. Taxa, which are similar to Bactrospora but never have fragmenting spores and have asci not easily separated from ascogenous hyphae and with a strongly hemi-amyloid inner endoascus, include the Opegrapha vulgata group (spores: with gelatinous sheath, brown when old, fusiform to acicular; paraphysoids: richly branched; excipular hyphae: without crystals; ascomata: lirelliform, not constricted, with slit-like to slightly widened disc) and the Lecanactis abietina group. Bactrospora differs from Lecanactis in the following features: asci Bactrospora-type, cylindrical, easily separated from ascogenous hyphae; without a strongly hemi-amyloid inner endoascus; paraphysoids sparsely and dichotomously branched; spores cylindrical, acicular or biclavate, with up to 45 septa, easily fragmenting; ascomata apothecioid, sessile, constricted at base; disc widened, epruinose; surface of excipular hyphae with crystals; hymenial strands absent (monocarpocentral); spores hyaline at all stages, without gelatinous sheath; pycnidia immersed to subimmersed; macroconidia absent; secondary chemical products absent, or occasionally unknown substances present.