Caloplaca haematommona
Caloplaca haematommona is a little-known species of corticolous, lichen in the family Teloschistaceae. It has a very thin, whitish, crust-like thallus dotted with black, spanning about 10–18 mm in width, and apothecia ranging from 0.2 to 0.8 mm in diameter, and becoming yellow-orange to brownish-orange as they mature. The lichen is known only from its type locality in Western Australia.
Taxonomy
The lichen was first formally described in 2007 by the lichenologists John Alan Elix and Sergey Kondratyuk. The type specimen was collected by the first author from Yilliminning Rock in Western Australia, which is situated to the east of Narrogin. Discovered on a dead shrub in a crevice of a rock and coexisting with an unclassified Caloplaca species, the specimen was located in a vast, open granite outcrop encircled by arid Eucalyptus forests, at an elevation of. The species name refers to the presence of haematommone, a rare metabolite in the genus Caloplaca.Description
Caloplaca haematommona has a crustose thallus that is very thin or almost absent, measuring approximately 10–18 mm in width. It is somewhat uneven and continuous, with a whitish appearance dotted with black, and is about 15 μm thick.The species features apothecia that range from 0.2 to 0.8 mm in diameter. Initially, these are or rarely, with a very thin or absent. They become distinctly sessile as they mature, featuring a well-developed approximately 50–75 μm thick, usually coloured yellow-orange to dull, brownish-orange. The ranges from brownish-orange to orange-red. The hymenium is about 60–70 μm high, underlain by a hyaline . Paraphyses in Caloplaca haematommona are distinctively septate, slightly wider towards the tips, and richly branched. have a thick cell wall at the poles, measuring 9–14 by 5–7 μm, with a septum 4–6 μm thick.
Chemical analysis using standard spot tests reveals that the and epithecium react K+, with the contents of the ascus becoming purplish. Major chemicals constituents include atranorin and haematommone.