Fissurina varieseptata
Fissurina varieseptata is a species of crustose lichen in the family Graphidaceae. It is known from Florida. It has small, fissure-like and ascospores that usually have 5–7 transverse septa, rather than the more typical three in closely similar species.
Taxonomy
Fissurina varieseptata was described as a new species in 2011 by Ralph Common and Robert Lücking. The holotype was collected in April 1997 in Fakahatchee Strand Preserve State Park, at Big Cypress Bend in an old-growth cypress swamp. It is deposited in the herbarium of the Michigan State University Museum.The specific epithet refers to the variable number of transverse septa in the ascospores. The species is superficially similar to Fissurina illiterata and may be closely related, but it can be separated by its much more strongly septate spores, a feature unusual in the genus.
Description
The thallus forms a continuous crust on bark, 1–5 cm across and about 40–70 μm thick. The surface is smooth to uneven and typically yellowish white. The is a alga. In cross-section, the upper is irregular and loosely developed, with an irregular and clusters of crystals.Individual lirellae are about 0.5–1 mm long and about 0.1 mm wide and high, with a complete. The is mostly concealed, and the are inconspicuous; the thalline margin is yellowish white but becomes yellow-brown along the slit. Microscopically, the asci are and produce eight ellipsoid ascospores. The spores are usually 5–7-septate, 12–18 × 4–5 μm, and non-amyloid. No lichen substances were detected by thin-layer chromatography.