Biology:Stegobolus
Stegobolus is a genus of lichen-forming fungi in the family Graphidaceae.[1] Established in 1845 by the French botanist Camille Montagne, the genus contains 16 species distinguished by their unique fruiting structures that initially appear drum-shaped and closed, later bursting open by shedding their roof-like covering. These bark-dwelling lichens are found in humid tropical and warm temperate forests worldwide, where they serve as indicators of undisturbed woodland habitats due to their sensitivity to canopy opening and drought.
Taxonomy
The genus Stegobolus was circumscribed in 1845 by the French botanist Camille Montagne, who assigned Stegobolus berkeleyanus as the type species. In his original description, Montagne characterised the genus by its crustaceous thallus and bursting apothecia that are initially drum-shaped and closed by a lens-like [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], which later splits around its circumference and opens widely when the epithecium falls away. He noted that the interior features a membranaceous [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] that tears open to reveal a gelatinous nucleus. Montagne observed that while the genus resembles Thelotrema in having a closed epithecium, it differs fundamentally in its mode of opening. He derived the genus name from the Greek words στεγος ('roof') and βάλλω ('to throw'), referring to the characteristic shedding of the epithecium. Montagne noted the strong morphological similarity between Stegobolus and Elastogia, and also drew comparisons to Craterio, though he noted that the orders are very different and not all features can be compared. The type specimen was collected by the Miles Joseph Berkeley from the Philippines, and Montagne dedicated this single species to Berkeley in recognition of his sharing of his Philippine cryptogam collection.[2]
Description
Stegobolus forms a smooth, pale grey-green to yellow-olive crust (thallus) that embeds directly in the bark and lacks a true [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]. Its [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] are short to elongate (0.5–3 mm), initially covered by a thin thalline veil that soon splits to expose a narrow, often faintly white-[[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] slit. The walls are entirely [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], creating sharp black outlines, while a colourless [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] borders the interior. The clear hymenium is non-[[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and traversed by smooth paraphyses; eight hyaline (colourless and translucent) ascospores mature in each Graphis-type ascus. These spores become distinctly [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]—divided by numerous transverse and a few longitudinal septa—measure roughly 25–60 × 8–14 μm, and remain negative to staining with iodine (I–). Most species are chemically poor or produce only trace amounts of stictic acid-series depsidones, a contrast to the anthraquinone-rich script lichens of some allied genera.[3]
The co-existence of fully carbonised lirellae, a non-inspersed hymenium and large, I– muriform spores distinguishes Stegobolus from superficially similar genera. Redingeria has an inspersed hymenium; Hemithecium and Acanthothecis possess spinulose [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]; Kalbographa is set apart by its vivid orange [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]; and the plate-forming Platygramme and Platythecium develop broader shields rather than narrow slits.[3]
Ecology
Stegobolus is pantropical to warm-temperate in distribution, recorded from lowland Amazonian rainforest, West-Central African evergreen stands, Indo-Malayan dipterocarp forest and moist sclerophyll woodlands in Queensland. All known species are corticolous, occupying shaded boles and large branches where high humidity and limited direct sunlight prevail; they decline rapidly after canopy opening or prolonged desiccation, so their presence is a practical indicator of long-standing, moisture-rich woodland habitat.[3]
Species
As of June 2025[update], Species Fungorum (in the Catalogue of Life) accepts 16 species of Stegobolus:[1]
- Stegobolus actinotus (Tuck.) Frisch & Kalb (2006)
- Stegobolus amazonus M.Cáceres, Aptroot & Lücking (2014)[4]
- Stegobolus anamorphoides (Nyl.) Lücking (2012)
- Stegobolus anamorphus (Nyl. ex Vain.) Frisch & Kalb (2006)
- Stegobolus auberianus (Mont.) Frisch & Kalb (2006)
- Stegobolus carneopustulatus Frisch & Kalb (2006)[5]
- Stegobolus croceoporus (Hale) Frisch (2006)
- Stegobolus fissus (Müll.Arg.) Frisch (2006)
- Stegobolus metaphoricus (Nyl.) Frisch (2006)
- Stegobolus percolumellatus (Sipman) Frisch (2006)
- Stegobolus polillensis (Vain.) Frisch (2006)
- Stegobolus pruinatus (Nagarkar & Hale) Frisch (2006)
- Stegobolus radians (Müll.Arg.) Frisch (2006)
- Stegobolus schizostomus (Tuck.) Frisch & Kalb (2006)
- Stegobolus subwrightii (Hale) Rivas Plata, Lücking & Lumbsch (2012)[6]
- Stegobolus wrightii (Tuck.) Frisch (2006)
References
- ↑ 1.0 1.1 "Stegobolus". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/7M6P.
- ↑ Montagne, J.P.F.C. (1845). "Plantae Cellulares quas in insulis Philippinensibus a cl. Cuming collectae recensuit, observationibus non nullis descriptionibusque illustravit". London Journal of Botany 4: 3–11. https://www.biodiversitylibrary.org/page/773157.
- ↑ 3.0 3.1 3.2 Lücking, Robert; Rivas Plata, Eimy (2008). "Clave y guía ilustrada para géneros de Graphidaceae" (in es). GLALIA 1 (1): 1–39. https://archive.org/details/2008_Glalia_1_1.
- ↑ Cáceres, Marcela E.S.; Aptroot, André; Parnmen, Sittiporn; Lücking, Robert (2014). "Remarkable diversity of the lichen family Graphidaceae in the Amazon rain forest of Rondônia, Brazil". Phytotaxa 189 (1): 87–136. doi:10.11646/phytotaxa.189.1.8. Bibcode: 2014Phytx.189...87C. https://www.researchgate.net/publication/287460701.
- ↑ Frisch, A.; Kalb, K. (2006). "A monograph of Thelotremataceae with a complex structure of the columella". Bibliotheca Lichenologica 92: 446.
- ↑ Rivas Plata, Eimy; Lücking, Robert; Lumbsch, H. Thorsten (2012). "Molecular phylogeny and systematics of the Ocellularia clade (Ascomycota: Ostropales: Graphidaceae)". Taxon 61 (6): 1161–1179 [1176]. doi:10.1002/tax.616001. Bibcode: 2012Taxon..61.1161R. https://www.researchgate.net/publication/286583636.
Wikidata ☰ Q7606700 entry
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