Calvitimela austrochilensis is a species of saxicolous (rock-dwelling), crustose lichen in the family Tephromelataceae, found in southern Chile and possibly on Marion Island. It has a creamy-white to yellow thallus with a cracked surface and distinctive blue-black reproductive structures. The lichen contains atranorin and other unidentified compounds and forms a symbiotic relationship with a green alga. First described in 2011 from a specimen collected on Desolación Island, it grows in moorland habitats and is known from only a few locations.
It was described as a new species in 2011 by the lichenologist Alan Fryday. The type specimen was collected on Desolación Island in Chile, along the southern side of Caleta San José in BahÃÂa Tuesday. It was found in a moorland habitat on a hill and was gathered on 4 October 1969 by Henry Imshaug and Karl Ohlsson (collection number 44725). The holotype is preserved at the Michigan State University Herbarium (MSC).
Calvitimela austrochilenis is a crustose lichen with a creamy-white to yellow thallus that spreads widely and has a distinct margin. The thallus is relatively thick, measuring 0.5âÂÂ1.5 mm, and features a thin bluish-grey at its edges. Its surface is cracked into small, flat that are smooth and measure 0.3âÂÂ0.5 mm across. Unlike some lichens, it lacks a protective outer but contains pale brown pigmentation in its surface cells. The medulla, or inner fungal layer, contains large, insoluble crystals measuring 15âÂÂ35 üm in diameter. The lichen's photosynthetic partner is a green alga, with individual cells measuring 12âÂÂ15 üm in diameter.
The apothecia (fruiting bodies) are embedded within the thallus and appear as small, blue-black that are typically round but may have slight irregularities. They range from 0.2 to 0.4 mm in diameter and have a concave surface. A narrow crack usually separates the apothecium from the surrounding thallus, though in some cases, remnants of the thallus adhere to it, forming a . The of the apothecium is usually indistinct, but when visible, it appears as a thin, slightly raised edge. The blue-black pigment within the apothecia sometimes extends patchily into the surrounding thallus.
Microscopically, the hymenium, the layer where spores develop, is 80âÂÂ90 üm tall and contains scattered . The paraphysesâÂÂthin, thread-like structures that support the developing sporesâÂÂare septate, occasionally branching and reconnecting, with a gelatinous sheath around 3 üm thick. Their tips are swollen to 5âÂÂ8 üm in diameter. The , the uppermost layer of the hymenium, is blue-black and reacts with chemical tests (H+ blue, N+ red) to produce a colouration. The , the tissue beneath the hymenium, is thick (approximately 300 üm), and though it is inherently colourless, it appears pale brown due to the presence of minute crystals that dissolve in potassium hydroxide solution (K).
The lichen produces cylindrical, Lecanora-type asci measuring 60âÂÂ70 by 15âÂÂ17 üm, each containing , colourless ascospores. These spores typically lack internal divisions but occasionally develop a thin septum and measure 10âÂÂ13 by 5âÂÂ7 üm. The exciple, a rim of protective tissue surrounding the apothecium, is sometimes visible as a band of golden-brown cells, but the is absent. No asexual reproductive structures (conidiomata) have been observed in this species.
Chemical analysis of C. austrochilenis reveals the presence of atranorin and additional unidentified substances, as detected by thin-layer chromatography.
In addition to the type locality, Calvitimela austrochilensis is known from only a few locations in southwest Chile, and from a single collection in Marion Island. This latter collection may represent a distinct species, as it has a less massively developed brownish hypothecium compared to the Chilean collections. Other lichens found close to C. austrochilensis include Lithographa olivacea and Pertusaria stellata.