Biology:Constrictolumina
Constrictolumina is a genus of lichen-forming fungi in the family Trypetheliaceae.[1] These tropical lichens form crusty growths that lack a protective outer layer and merge directly with their growing surface. They produce cone-shaped fruiting bodies that push up through the crust and release spores through a tiny opening at the tip. The genus gets its name from the distinctive spores, which have internal walls that fold inward and create narrowed, constricted spaces inside each spore.
Taxonomy
The genus was circumscribed in 2016 by Robert Lücking, Matthew Nelsen, and André Aptroot, with Constrictolumina cinchonae assigned as the type species. The genus contains tropical species, formerly placed in genus Arthopyrenia, with a unique hamathecium.[2]
Description
Constrictolumina has a thallus that lacks a differentiated outer "skin" (non-corticate). In practice this means the crust has no distinct protective [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and merges more directly with the substrate. The sexual fruiting bodies (apothecia) are produced singly and are roughly conical, pushing up through the thallus ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) so that they sit partly to fully exposed; neighbouring fruit bodies may fuse sideways but they do not form larger compound structures (no [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]). Each fruit body has a tiny pore at the top (an apical ostiole) through which the ascospores are released.[2]
Internally, the fruit body contains a clear, colourless tissue ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) made of straight filaments that are thicker at the base and slimmer towards the top; these filaments do not fuse with one another. The spore sacs (asci) are club-shaped. The spores are colourless (hyaline) and usually divided by one to three cross-walls (1–3-septate), only rarely showing additional, partial longitudinal divisions ([[Glossary of lichen terms#{{biology:{1}}}|submuriform]]). A diagnostic feature is the irregular thickening of the inner spore wall ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]): one or two cells within a spore often develop inward wall "folds" that look like incomplete septa ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]), giving the internal cavities a narrowed, constricted appearance—hence the genus name. Spore surfaces may be smooth or ornamented; they often develop a fine, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] ornamentation and only very rarely turn slightly brown with age. Small asexual structures (pycnidia) may also be present.[2]
Species
Five species are accepted in Constrictolumina:[1]
- Constrictolumina cinchonae (Ach.) Lücking, M.P.Nelsen & Aptroot (2016)
- Constrictolumina esenbeckiana (Fée) Lücking, M.P.Nelsen & Aptroot (2016)
- Constrictolumina leucostoma (Müll.Arg.) Lücking, M.P.Nelsen & Aptroot (2016)
- Constrictolumina planorbis (Ach.) Lücking, M.P.Nelsen & Aptroot (2016)
- Constrictolumina porospora (Vain.) Lücking, M.P.Nelsen & Aptroot (2016)
Some species placed in Constrictolumina have since been transferred to the genus Macroconstrictolumina, newly circumscribed in 2020.[3]
References
- ↑ 1.0 1.1 "Constrictolumina". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/3THN.
- ↑ 2.0 2.1 2.2 Lücking, Robert; Nelson, Matthew P.; Aptroot, André; Barillas de Klee, Roselvira; Bawingan, Paulina A.; Benatti, Michel N.; Binh, Nguyen Quoc; Bungartz, Frank et al. (2016). "A phylogenetic framework for reassessing generic concepts and species delimitation in the lichenized family Trypetheliaceae (Ascomycota: Dothideomycetes)". The Lichenologist 48 (6): 739–762. doi:10.1017/S0024282916000505.
- ↑ Hongsanan, Sinang; Hyde, Kevin D.; Phookamsak, Rungtiwa; Wanasinghe, Dhanushka N.; McKenzie, Eric H.C.; Sarma, V. Venkateswara et al. (2020). "Refined families of Dothideomycetes: orders and families incertae sedis in Dothideomycetes". Fungal Diversity 105 (1): 17–318. doi:10.1007/s13225-020-00462-6.
Wikidata ☰ Q105492698 entry
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