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Buellia pseudomicromera (Marbach) Bungartz
Family: Caliciaceae
Buellia pseudomicromera image
Buellia pseudomicromera: (Marbach) Bungartz, comb. nov.: Basionym: Baculifera pseudomicromera Marbach, Bibl. Lich. 74: 141 (2000); Illustration: Marbach (2000), p. 143; Taxonomic affinity: Baculifera-group. Thallus: crustose, rimose to rimose-areolate, thin, ±continuous; prothallus: absent or delimiting the thallus as a black outline surface: pale white to ivory, dull, epruinose, phenocorticate, esorediate medulla: white, lacking calcium oxalate (H2SO4-) Apothecia: lecideine; (0.2-)0.3- 0.4(-0.5) mm in diam., soon sessile margin: black, thin, rarely persistent, usually excluded with age disc: black, epruinose, plane, soon becoming convex proper exciple: similar to the dispersa-type, inner excipular hyphae distinct, not reduced, pigmented, prosoplectenchymatous (textura oblita), extending from the deep reddish brown hypothecium (leptoclinoides-brown, textura intricata), outer excipular hyphae short-celled, ±cells angular, distinctly swollen (textura angularis) pale brown, weakly carbonized with small amounts of a dull greenish brown pigment (micromera-green HNO3+ grayish black, K+ green, HCl+ intensifying bluish green) epihymenium: greenish brown, pigmentation continuous with the outer exciple hymenium: hyaline, not inspersed with oil droplets; paraphyses: simple to moderately branched, apically swollen, with a dull greenish brown pigment cap (micromeragreen, K+ green, HCl+ turning bluish green) asci: clavate, Bacidia-type, 8-spored ascospores: soon brown, 1-septate, occasionally with two additional false septa, narrowly ellipsoid to ±narrowly citriform, not constricted, with pointed ends, not curved, (13.5-)14.3-[15.5]-16.8(-18.5) x (4-)4.7-[5.2]-5.8(-6.5) µm (n=25); proper septum: becoming soon but only briefly thickened during spore ontogeny, lateral wall inconspicuously thickened (±Callisporatype); ornamentation: microrugulate (best seen in DIC) Pycnidia: rare, globose, unilocular; ontogeny similar to the Umbilicaria-type conidiogenous cells: mostly terminal, rarely also intercalary (cf. conidiophore-type V) conidia: elongate bacilliform, straight, 6.5-10(-13) x 0.5- 1 µm (n=30) Spot tests: K+ yellow (Sonoran material not forming crystals), P-, C- fluorescence: UV- (pale) iodine reaction: medulla non-amyloid Secondary metabolites: atranorin, ±norstictic acid. Substrate and ecology: currently known only from twigs of Jatropha, elsewhere on wood World distribution: according to Marbach (2000) a tropical-subtropical species previously known only from South America (Brazil), and Africa (Kenya) Sonoran distribution: Sinaloa and southernmost Sonora. Notes: The Sonoran specimens of B. pseudomicromera agree well with the description by Marbach (2000). The K+ greenish yellow reaction that shifts in HCl towards a bluish green is due to a yet undescribed pigment with a color similar to cinereorufa-green. However, unlike cinereorufa-green, the pigment in B. pseudomicromera reacts HNO3+ black instead of violet. The K+ yellowish or greenish reaction is not always obvious, but the shift to blue-green, if HCl is subsequently applied, is conspicuous. The name micromera-green is proposed following the pigment nomenclature sensu Meyer and Printzen (2000). As reference the exsiccatae collections of B. micromera (Kalb, Lich. Neotropici 359; type specimens of Buellia epichlorina) are selected here. The same pigment is currently known from B. micromera Vainio, B. entochlora J. Steiner, B. xylophila Malme, and B. conspirans (Nyl.) Vain. Marbach (2000) emphasized the presence of micromera-green for these species and includes all except Buellia conspirans within his recently erected genus Baculifera. He regards Baculifera as being closely related to "Hafellia" because of a similar spore type, but lacking oil inspersion in the hymenium. Other diagnostic characters for Baculifera according to Marbach (2000) are the presence of norstictic acid in the thallus and elongate bacilliform conidia (referred to as baculiform, hence the genus name). Buellia conspirans is the only species with micromera-green not placed into the newly proposed genus, but, because of its oil inspersed hymenium, was treated as "Hafellia" (treated by Marbach 2000 as H. curatellae (Malme) Marbach; the name B. conspirans has taxonomic priority, H. curatellae is reduced here to synonymy). Buellia micromera, a species without oil inspersion, but also lacking baculiform Conidia as well as norstictic acid, is nevertheless placed into Baculifera. Sonoran material of B. pseudomicromera lacks norstictic acid or possibly contains only minute traces, but it has elongate bacilliform conidia. It is not unusual to observe this chemotypic variation; in fact norstictic acid is a very common lichen substance and several other species that typically contain norstictic acid may occasionally lack this secondary metabolite. We therefore include the acid deficient Sonoran material in B. pseudomicromera. At this point the genus concept of Baculifera is obviously not well established and we therefore transfer B. pseudomicromera into Buellia s.l.