Slideshow image
Buellia halonia (Ach.) Tuck.
Family: Caliciaceae
Buellia halonia image
Stephen Sharnoff  
Thallus: crustose, areolate, thick, ±continuous; prothallus: distinct, delimiting the thallus as a black outline surface: usually yellowish green to pale yellow, rarely becoming brownish (older herbarium specimens), dull or ±shiny, smooth, epruinose, phenocorticate, esorediate medulla: white, but in the lower parts occasionally with a distinctly rust-red, K+ purplish pigment (possibly chiodectonic acid), lacking calcium oxalate (H2SO4-) Apothecia: lecideine; (0.2-)0.3-0.5(-0.7) mm in diam., initially immersed, young apothecia frequently ±aspicilioid, soon bursting through the thallus surface and becoming adnate to sessile margin: black, prominent, usually persistent, rarely excluded with age, at early stages often covered by coarse thallus fragments disc: black, epruinose or sometimes with yellowish pruina, plane, rarely becoming strongly convex with age proper exciple: distinct, leptocline-type, thick and not distinctly differentiated into an inner and outer part, hyphae thin-walled (mesodermatous), prosoplectenchymatous and usually ±densely interwoven (textura intricata), dull fuscous brown to aeruginose throughout, becoming ±carbonized by various amounts of brown and aeruginose pigments (cf. elachista-brown and cinereorufa-green, HNO3+ violet), aeruginose pigment not extending into the deep reddish brown hypothecium (leptoclinoides-brown, textura intricata) epihymenium: brown, pigmentation continuous with the outer exciple (HNO3-) hymenium: hyaline, not inspersed with oil droplets; paraphyses: simple to moderately branched, apically swollen, with a brown pigment cap (cf. elachista-brown) asci: clavate, Bacidiatype, 8-spored ascospores: soon brown, 1-septate, oblong to ellipsoid, usually not constricted, with obtuse ends, not curved, (11.5-)12.4-[14.1]-15.7(-19) x (6-)6.8-[7.4]-8(-9) µm (n=60); proper septum: becoming distinctly thickened during spore ontogeny (Physconia-type); ornamentation: weakly microrugulate (in DIC) Pycnidia: rare, urceolate to globose, unilocular; ontogeny similar to the Umbilicaria-type conidiogenous cells: mostly terminal, rarely also intercalary (cf. conidiophore-type V) conidia: bacilliform, 5-7 x 1-1.5 µm (n=20) Spot tests: K+ yellow, P+ orange, C+ orange, KC+ orange, CK+ orange fluorescence: UV+ bright yellow to orange iodine reaction: medulla non-amyloid Secondary metabolites: arthothelin, isoarthothelin, 2,4-dichloronorlichexanthone, 2,5-dichloronorlichexanthone, 2,7-dichloronorlichexanthone, 4,5-dichloronorlichexanthone, 4,5-dichloronorlichexanthone, 5,7-dichloronorlichexanthone, atranorin, thiophanic, thiophaninic, and norstictic acids, and eumitrin x and eumitrin y (J. A. Elix, HPLC). Substrate and ecology: epilithic, on siliceous mineral-poor coastal rock (generally HCl-) World distribution: the Pacific coast of North and South America; recently also found along the west coast of southern Africa (Namib Desert) Sonoran distribution: along the coast of southern California, Baja California, and Baja California Sur. Notes: Buellia halonia can be easily recognized by its yellowish green, C+ orange, areolate thallus, its thick, aeruginose exciple, and its spores with a conspicuously thickened septum. It is one of the few species of Buellia that often contain a rust-red, K+ deep purple pigment within its lower medulla. Until recently, this pigment was overlooked, as it is typically only observed if several areoles are sectioned. In Australia a very similar species has recently been described from inland localities as B. molonglo U. Grube & Elix (Grube et al. 2004).
Buellia halonia image
Stephen Sharnoff  
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Jason Dart  
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Jason Dart  
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Buellia halonia image
Jason Dart  
Buellia halonia image
Buellia halonia image
Buellia halonia image