Fissurina confusa
Fissurina confusa is a lichen that forms a thin, crust-like growth on bark and belongs to the family Graphidaceae. It was first described from collections made in Florida. It is distinguished by prominent, lip-like, ascospores, and thallus chemistry dominated by psoromic acid.
Taxonomy
The species was described as new in 2011 by Ralph Common and Robert Lücking. The holotype was collected in April 1997 in Fakahatchee Strand Preserve State Park, along the K2 trail in a second-growth area among royal palms. It is housed in the herbarium of the Michigan State University Museum.The epithet confusa refers to the species having been previously confused with Fissurina instabilis. It was separated from F. instabilis by its consistent production of psoromic acid; the type material of F. instabilis lacks detectable lichen substances.
Description
The thallus forms a crust on bark, typically 1–3 cm across and about 50–100 μm thick. It forms a continuous crust with an uneven to warty, blistered surface, ranging from yellowish green to olive-brown. The is a alga.The lirellae are straight to curved and usually unbranched. They become and prominent. Individual lirellae are about 0.5–1 mm long and 0.15–0.2 mm wide, with a lateral. The is partly exposed and often gray-, while the are thick and white.
Microscopically, the asci are and typically contain eight ellipsoid ascospores. The spores are, with about 5–7 transverse rows and 1–3 longitudinal septa, and measure about 25–35 × 12–20 μm. The ascospores are amyloid, meaning they stain in iodine-based tests. Chemically, the thallus contains psoromic acid together with subpsoromic acid and 2'-O-demethylpsoromic acid. The medulla reacts P+ in standard spot tests.