Biology:Placolecis sublaevis
| Placolecis sublaevis | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Catillariaceae |
| Genus: | Placolecis |
| Species: | P. sublaevis
|
| Binomial name | |
| Placolecis sublaevis A.C.Yin & Li S.Wang (2019)
| |
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| Holotype site: Lijiang City (Yunnan, China)[1] | |
Placolecis sublaevis is a species of saxicolous (rock-dwelling), crustose lichen in the family Catillariaceae.[2] It is found in Yunnan and Sichuan, China. The crust-like, radiating body of the lichen forms irregular patches or clumps and includes numerous false [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], a type of asexual reproductive structure, within its thallus. Its [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], dark brown and slightly flattened at the top, form larger groups at the edges and contain an upper layer composed of loosely interwoven cells and a lower inner tissue that varies from reddish-orange to white.
Taxonomy
The lichen was formally described as a new species in 2019 by An-Cheng Yin and Li-Song Wang. The type specimen was collected by Wang and colleagues on the way from Lijiang to Ninglang (Lijiang City, Yunnan province) at an elevation of 1,902 m (6,240 ft). This specimen was found growing on limestone. The species name sublaevis alludes to the somewhat flattened shape of the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] at their tips.[1]
Description
Placolecis sublaevis has a crustose (crust-like) to [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (radiating) thallus. In the centre, it has an [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]-[[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (divided into small, scale-like sections) structure, forming irregular patches or clumps. The thallus incorporates numerous [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (false [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], a type of asexual reproductive structure) that are immersed within it. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] of this lichen distinctively form larger aggregations at the margins, measuring 2–3 (occasionally up to 4) mm long and 0.1–0.3 mm wide in the middle, slightly widening towards the tips to 0.15–0.4 mm. These lobes are dark brown and slightly flattened at the apex, often with secondary [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] branching from the main lobes and reaching 1–2 mm in length.[1]
The lichen's upper surface is dark brownish with an uneven texture. Its upper [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], the outermost layer, is 12.5–20 µm thick with a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (loosely interwoven) structure. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is diffuse, spanning 25–40 µm in thickness, with Trebouxia-like [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (symbiotic green algae) cells measuring 6–12 µm in diameter. The medulla (the inner tissue of the thallus) varies in thickness from 60 to 140 µm and shows a reddish-orange colouration in the upper portion, transitioning to white in the lower portion. This species does not have a lower cortex, nor does it have apothecia (fruiting bodies).[1]
Reproductive structures, known as [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], are numerous and immersed within the thallus. They measure 75–95 by 40–60 µm, are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (jug-shaped), and have a black ostiole (opening). The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (asexual spores) of this species are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (rod-shaped) and measure 5–6 µm.[1]
In terms of reactions to standard chemical spot test, the medulla of Placolecis sublaevis is K+ (violet) in its upper yellow part, as well as P− and C−. Chemical analysis using thin-layer chromatography shows the presence of fragilin, solorinic acid, and anthraquinones.[1]
Habitat and distribution
This species is found in the high mountain regions of Yunnan and Sichuan in southeast China, specifically on exposed steep slopes adorned with limestone boulders near streams.[1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Yin, An Cheng; Wang, Xin Yu; Liu, Dong; Zhang, Yan Yun; Yang, Mei Xia; Li, Li Juan; Wang, Li Song (2019). "Two new species of Placolecis (lichenized Ascomycota) from China". Mycobiology 47 (4): 401–407. doi:10.1080/12298093.2019.1672984. PMID 32010461.
- ↑ "Placolecis sublaevis A.C. Yin & Li S. Wang". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/9ZDND.
Wikidata ☰ Q108241939 entry
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