Phaeographis striata
{{Short description|Species of lichen}}
{{Use dmy dates|date=March 2023}}
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| taxon = Phaeographis striata
| authority = Bungartz (2010)
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Phaeographis striata is a species of script lichen in the family Graphidaceae, endemic to the Galápagos Islands. It is characterized by its inconspicuous thallus and striate (grooved) {{lichengloss|thalline margins}} of the {{lichengloss|lirellae}}. The species is found in the lower transition zone, growing on columnar cacti and other plants native to the region.
Taxonomy
Phaeographis striata was first described by Frank Bungartz in 2007, who designated a holotype collected from San Cristóbal Island, Cerro Partido in the Galápagos Islands. The species is similar to Fissurina columbina but has apical carbonized {{lichengloss|excipules}} and brown {{lichengloss|ascospores}}. The name Phaeographis striata refers to the striate (furrowed) thalline margins of the {{lichengloss|lirellae}}.
Description
The thallus of Phaeographis striata is thin, inconspicuous, and almost entirely embedded in the {{lichengloss|substrate}}. Its surface is smooth, not {{lichengloss|pruinose}}, and of the same color as the substrate or slightly darker and more yellowish-orange. The {{lichengloss|apothecia}} are immersed, lirellate, and initially {{lichengloss|fissurine}}, with thin, elongate, and moderately to sparsely branched lirellae. The labia are thin and narrow, surrounded by a striate thalline margin composed of several papery thallus layers. The {{lichengloss|disc}} is initially fissurine but soon expands, becoming immersed, flattened, blackened, and covered by {{lichengloss|farinose}} whitish pruina. The {{lichengloss|exciple}} is thin, with apical {{lichengloss|carbonisation}} and an aeruginose pigment that fades laterally and is unpigmented basally. The hymenium is translucent, with pale gray ascospores that soon turn brown, measuring 17–23 by 7–9 μm and usually containing 4–6 cells.
Habitat and distribution
Phaeographis striata is currently known only from the Galápagos Islands, specifically from the Alcedo Volcano on Isabela Island and San Cristóbal Island. It is considered endemic to the region and grows in the lower transition zone (an ecological region where vegetation and habitats transition between the arid lowlands and the humid highlands), on the columnar cactus Jasminocereus thouarsii and the tree Bursera graveolens.
References
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{{Catalogue of Life |id=76W4T |title=Phaeographis striata Bungartz |access-date=30 March 2023}}
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Category:Lichens described in 2010