Heppia lutosa
Heppia lutosa is a species of jelly lichen in the family Porocyphaceae. The species forms small scaly lobes up to 10 mm across that are attached to the substrate by a central point, with a dark olive upper surface and a pale to reddish-brown underside. It occurs in Africa, Europe, and North America.
Taxonomy
The species was first scientifically described in 1814 by Erik Acharius, who named it Collema lutosum based on material growing on muddy soil in Germany; in his brief Latin he characterised it as a crustose, cracked, - and wrinkled, yellowish-green lichen with large immersed apothecia whose are flat to slightly convex and become pale reddish when moist. William Nylander reclassified the species in Heppia in 1869.Description
Heppia lutosa has a thallus made up of small, leaf-like that are rounded to irregularly lobed and measure up to about 10 mm across. The are attached to the substrate by a central and range from flat or slightly wavy to distinctly convex, with margins that typically curve downwards. The upper surface is smooth and dark olive in colour, underlain by a thin surface layer. The underside is also smooth, and varies from pale flesh-brown to deep reddish or almost blackish brown; its cortex is formed of tissue that may appear -like and is about 10–50 micrometres thick. The medulla is differentiated into an upper zone containing the, which occupies about one-quarter to three-quarters of the medullary depth, and a lower zone of loose, algae-free fungal hyphae.Asexual reproduction occurs through soredia, which are produced in usually well-defined soralia situated either along the margins or across the surfaces of the squamules. Sexual fruiting bodies are commonly numerous on each squamule; they are immersed in the thallus so that only the is visible at the surface, ranging from to about 0.7 mm in diameter. The ascospores are ellipsoid and relatively small, measuring about 6–8 by 3–5 μm.