About Leproplaca cirrochroa (Ach.) Arup, Frödén & Søchting
Leproplaca cirrochroa is a distinctive lichen species that can grow up to 5 cm (2 in) across. It has a placodioid thallus made up of narrow, finger-like lobes that lie tightly pressed against its growing surface. These lobes are intricately divided, and form irregularly rounded groupings, or sometimes occur as small, scattered or connected individual thalli. The colour of Leproplaca cirrochroa ranges from dirty orange to brown-orange, and the ends of its lobes are often paler orange and covered in a fine powdery coating (pruinose). Lobe ends are typically 0.2–0.5 mm wide, rounded, and occasionally forked. They are shallowly convex, elongated, usually lie close together, and are separated by nearly parallel furrows. Soralia (structures that produce soredia for asexual reproduction) are usually present on the main surface of the thallus, scattered across its area. These soralia are small, flat, rounded, and can reach up to 0.8 mm in diameter. The soredia they produce are powdery (farinose) and lemon-yellow in colour. Apothecia, the sexual fruiting bodies of this lichen, are rare; when they do occur, they measure up to 0.5 mm in diameter and are scattered across the thallus. Present apothecia are flat, with a persistent, orange thalline margin. The apothecial disc is a deeper shade of orange. The paraphyses, which are filament-like support structures within the apothecia, are winding (flexuose) and mostly not swollen at their tips. Ascospores are narrowly ellipsoid, measuring 10–15 by 5 μm, with a central septum 2–3 μm wide that makes up less than one-third of the total ascospore length. All parts of this lichen give a K+ (purple) colour reaction in chemical spot testing. Leproplaca cirrochroa is widely distributed, and has been recorded from Africa, Asia, Australia, Europe, and North and South America.
