Acanthothecis celata
Acanthothecis celata is a species of corticolous script lichen in the family Graphidaceae. It forms a thick, snow-white crust with fruiting bodies that are largely hidden within the thallus. The species is known only from lowland evergreen forest in Karnataka, India.
Taxonomy
Acanthothecis celata was described as new to science in 2010 by Bharati Sharma, Urmila Makhija and Pradnya Khadilkar, based on material collected in the Indian state of Karnataka. The type specimen was gathered on 27 January 1980 along the Peercode–Hiriadka route at roughly 200 ft elevation, and the holotype is preserved in the Ajrekar Mycological Herbarium.In the original description it was compared most closely with Acanthothecis albescens, which has similarly sized ascospores but differs in producing stictic acid. The species was also separated from superficially similar species such as A. mirabilis and A. sanguinoloba, which have small, transversely septate spores but develop more conspicuous fruiting bodies, grooved, and an isohypocrelline pigment.
Description
The lichen forms a snow-white, crust-like thallus that is thick, granular and mealy-looking, and finely cracked, with a thin bordering hypothallus. Its fruiting bodies are immersed and usually concealed by the thallus; they tend to become apparent only when the surface is moistened, when irregular outlines can be seen within the white crust. Individual ascomata are about 0.5–1.5 mm long and 0.2–0.3 mm wide, with a moderately thick. The spore-bearing surface is hidden beneath dense white, but when wet it shows through as reddish brown to almost blackish red.Microscopically, the is not and lacks striations. The hymenium is clear and 125–145 μm tall, and it does not stain in iodine tests ; the is distinct, light yellow, and about 10–12.5 μm thick. The paraphyses branch near their tips, the are short with faint warting, and the asci contain 4–8 spores. The ascospores are hyaline, elongate and tapered at the ends, with 8–10 transverse septa, measuring 35–43 × 7–10 μm, and they are also iodine-negative. No lichen secondary metabolites were detected by thin-layer chromatography.