Cora fimbriata is a rare species of basidiolichen in the family Hygrophoraceae. It is found in Colombia. This small lichen forms leaf-like rosettes up to 3 cm across that grow on tree bark, distinguished by distinctive white hair-like fringes along the edges of its that give the species its name. Described as new to science in 2014 from a single location in Casanare Department at 1450 metres elevation, it is currently known only from its type locality where it grows among mosses in partially shaded microhabitats.
The lichen was formally described as a new species in 2014 by Leidy YasmÃÂn Vargas, Bibiana Moncada, and Robert Lücking. The type was collected in Finca El Paraiso (Vereda Centro Sur, Chámeza) at an altitude of . It is only known to occur at the type locality, where it grows on tree bark in association with bryophytes in partially exposed microhabitats. The specific epithet fimbriata refers to the that are fringed on the margins of the lobes.
Cora fimbriata forms small, leaf-like rosettes that cling to tree bark in the humid spaces between moss cushions. Each thallus (the overall lichen body) is seldom more than 3 cm across and typically consists of one to three semicircular lobes. Individual lobes measure 1âÂÂ2.5 cm in width and 1âÂÂ1.5 cm in length; they fork once to three times, and fine "sutures" run between the branches like seams in fabric. When moist the upper surface is a dark olive-grey, drying to a plain grey in the herbarium. It is smooth to the touch but shows faint concentric wrinkles. Along the lobe margins and within the sutures the lichen bears a fringe of short, white âÂÂfine, hair-like projections that give the species its name. The lower surface is patterned with alternating white and grey rings, a feature that remains visible whether the specimen is fresh or dry.
A thin vertical slice through a lobe reveals a three-layered structure 0.22âÂÂ0.30 mm thick. The outer , measuring 110âÂÂ130 micrometres (üm) thick, acts like a protective skin; its fungal threads (hyphae) are arranged first parallel to the surface () and then, in a deeper sub-layer, roughly perpendicular (). Beneath lies the (75âÂÂ100 üm), where cyanobacteria occur in tight emerald-green clusters 25âÂÂ30 üm across. Each bacterial cell is 10âÂÂ15 üm wide and enveloped by a sheath of interlocking fungal cells, with additional hyphae 5âÂÂ7 üm thick weaving through the layer. The innermost medulla (55âÂÂ75 üm) is a looser mesh of mostly periclinal hyphae 1âÂÂ3 üm in diameter. No hymenophoreâÂÂthe spore-bearing tissue typical of many basidiolichensâÂÂhas yet been observed in this species, and thin-layer chromatography detects no secondary metabolites in the thallus.