Tapellaria floridensis is a species of crustose lichen in the family Ectolechiaceae. It is known from subtropical Florida and has black apothecia (disk-like fruiting bodies) with margins that are often conspicuously gray and dusted with , especially when young.
Tapellaria floridensis was described as a new species in 2011 by Ralph Common and Robert Lücking. The holotype (the specimen the name is based on; Common 7322A) was collected in April 1997 in Fakahatchee Strand Preserve State Park (Collier County, Florida), along the Scenic Drive (CR 837) near the bend near gate 14 in second-growth habitat; it is deposited in the herbarium of the Michigan State University Museum (MSC). Duplicate material is reported for the University of South Florida herbarium (USF) and Common's personal herbarium.
The specific epithet floridensis refers to the state of Florida. The species was compared especially with Tapellaria malmei, which has a similar ascospore type (shape and internal divisions) but differs in having young apothecia without and larger ascospores.
The thallus (lichen body) is corticolous (growing on bark) and typically 1âÂÂ2 cm across and about 30âÂÂ50 micrometers (üm) thick. It forms a continuous crust with an uneven surface that is white to pale gray, and it contains a photobiont (a green alga that provides photosynthesis).
The apothecia are (sitting directly on the thallus, without a stalk) and rounded, about 0.3âÂÂ0.7 mm in diameter and 170âÂÂ270 üm high. The disk (the exposed spore-bearing surface) is black, concave when young, and becomes flat to slightly convex with age. The margin is thick and prominent and is typically covered with a gray layer (often strongest in younger apothecia) that may wear away with age.
Under the microscope, the (the rim tissue around the apothecium) is dark purplish brown, and the (tissue beneath the hymenium) is also dark purplish brown; the K test is positive (K+), giving a purplish reaction. The hymenium (spore-producing layer) is about 100âÂÂ120 üm high and is colorless to faintly purplish toward the top. It has branched, net-like paraphyses (anastomosing filaments), and the asci (spore sacs) are about 90âÂÂ110 à18âÂÂ25 üm. The ascospores are ellipsoid and (divided into many small compartments), produced 4âÂÂ8 per ascus, and measure about 20âÂÂ25 à9âÂÂ12 üm; no lichen substances were detected by thin-layer chromatography.
The species also produces (asexual spore-producing structures) that are sessile and hood-shaped, with a black lobe, and it forms filiform, curved conidia that are multiseptate (reported as 7âÂÂ13 septa). In Tapellaria, species are mainly separated by ascospore size and septation (number and pattern of internal divisions) and by whether pruina is present on the apothecial margin; this is the main feature used to distinguish T. floridensis from similar taxa.
Tapellaria floridensis is morphologically similar to Tapellaria parvimuriformis and can be confused with it. It is separated by its white to pale grey thallus, black campylidia (gray with a whitish base in T. parvimuriformis), and longer conidia (80âÂÂ90 üm rather than 45âÂÂ50 üm).
Tapellaria floridensis is known from two collections from Fakahatchee Strand Preserve State Park in southwestern Florida. It was recorded growing on branches and trunks of hardwoods in second-growth habitat (regrown forest) along the park's Scenic Drive near gate 14.