Pyxine subcinerea

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Pyxine subcinerea
Pyxine subcinerea Stirton 420916.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Caliciales
Family: Caliciaceae
Genus: Pyxine
Species:
P. subcinerea
Binomial name
Pyxine subcinerea
Stirt. (1898)
Synonyms [1]
  • Pyxine cocoes var. caesiopruinosa Tuck. (1869)
  • Pyxine meissneri var. sorediosa Müll.Arg. (1879)
  • Physcia melanenta C.Knight (1882)
  • Pyxine sorediata f. caesiopruinosa(Tuck.) Hue (1900)
  • Pyxine chrysanthoides Vain. (1915)
  • Pyxine caesiopruinosa(Tuck.) Imshaug (1957)

Pyxine subcinerea is a species of foliose lichen in the family Caliciaceae. It has a pantropical distribution, and typically grows on bark, but less commonly on rocks. The lichen is characterised by its yellow medulla, soralia on the margins on the lobes that make up the thallus, and the presence of the chemical lichexanthone in the cortex.

Contents

Taxonomy

The lichen was first formally described by the Scottish scientist James Stirton from specimens collected in Queensland, Australia. He noted that its thallus was similar to that of Pyxine sorediata , but Stirton distinguished it from that species by the "internal organization of both the thallus and the apothecia", as well as the negative K reaction of the thallus, compared to the yellow reaction of P.  sorediata. [2]

Synonyms of Pyxine subcinerea include: [1] Physcia melanenta, described by Charles Knight in 1882; [3] Pyxine chrysanthoides, described by Edvard August Vainio in 1915 from material collected in the Antilles; [4] Pyxine meissneri var. sorediosa, described by Johannes Müller Argoviensis in 1879; [5] and Pyxine cocoes var. caesiopruinosa, described by Edward Tuckerman in 1869 [6] (and later promoted to distinct species status as Pyxine caesiopruinosa by Henry Andrew Imshaug in 1957). [7]

Description

Closeup of lobes; the scale bar is 0.5 mm. Pyxine subcinerea - Flickr - pellaea.jpg
Closeup of lobes; the scale bar is 0.5 mm.

The thallus of Pyxine subcinerea is 3–8 cm (1.2–3.1 in) wide, with an upper surface ranging in colour from yellowish grey to grey to brownish grey or olive-grey. The lobes that comprise the thallus are 0.3–1.5 mm (0.01–0.06 in) wide, somewhat tightly apressed to the substrate and are more or less flat but often somewhat concave near the tips. The lobe surface are pruinose, with the pruina resembling dense points near the lobe tips. [8] These pruina contain weddellite, a mineral form of calcium oxalate. [9] There are distinct pseudocyphellae at the margins of the lobes. The soralia are near the lobe margins. The medulla is quite thin and yellow above. The lower surface is black in the centre, but becomes paler towards the margin. Rhizines are more or less dense, and divided into branches. [8] The upper cortex is paraplectenchymatous (a cell arrangement where the hyphae are oriented in all directions), while the lower cortex is prosoplectenchymatous (a cell arrangement where the hyphae are all oriented in one direction). [10] Apothecia (reproductive structures) are common in tropical and subtropical specimens; they measure 0.3–1.5 mm (0.01–0.06 in) wide and have an indistinct internal stipe. [8] In contrast, apothecia are not typically associated with European material. [10] Ascospores measure 13–22 by 6–9  μm. The conidia are bacilliform, and measure 3–4 μm by about 1 μm. [8]

The secondary chemical in Pyxine subcinerea is lichexanthone. [8] The presence of this compound results in a golden-yellow colour when illuminated with UV light. [11] All lichen spot tests are negative. [10]

Pyxine subcinerea in 365 nm ultraviolet light Pyxine subcinerea Missouri Ultraviolet.jpg
Pyxine subcinerea in 365 nm ultraviolet light

Habitat and distribution

Pyxine subcinerea has a mostly pantropical distribution. Although it is generally found growing on bark, it has also been found growing on rock, [10] and, in one instance, on mortar. [11] In Europe, it has been reported from the Azores and Italy. [10] It has been reported from Africa (Ethiopia, Uganda, Kenya, Tanzania, the Seychelles, Rwanda and Angola), [12] throughout Asia (including China), [13] Australia, [8] New Zealand, [14] In the eastern United States, its geographical range covers subtropical to more temperate regions, including the states of New York, Illinois, and Ohio to Florida, Louisiana, and Texas. Pyxine subcinerea has been recorded growing on hornbeam, hickory, hibiscus, juniper, sweetgum, magnolia, oak, locust, elm, and the genus Prunus . It tends to prefer low elevations, and occurs hardwood-pine forests as well as more open areas including farms, glades, and gardens. [11]

Pyxine subcinerea is relatively resistant to air pollution, and has been investigated for use as a candidate for biomonitoring. It bioaccumulates toxic heavy metals that it acquires from the air and retains the pollutants in the thallus, which can then be sampled and assayed to determine their concentration. [15] [16]

Related Research Articles

<i>Pyxine</i> Genus of lichens

Pyxine is a genus of foliose lichens in the family Caliciaceae. The genus has a widespread distribution in tropical regions.

<i>Physcia</i> Genus of lichens

Physcia is a genus of lichen-forming fungi in the family Physciaceae. The widely distributed genus contains about 80 species. The genus is cosmopolitan, and has been extensively studied in various regions in the past several decades, with significant biodiversity in South America identified as a central diversity hotspot. Physcia species are foliose, lobate lichens that grow with a loose to close appressed habit. Their upper surface is typically whitish, pale greenish, green-grey, or dark grey in colour. The thallus colour remains relatively unchanged when moistened. Physcia lichens typically grow on bark, on wood, or rock, although they have occasionally been recorded dwelling on man-made structures. They thrive in nutrient-rich environments and are expanding rapidly in urban areas of the United Kingdom previously affected by SO2 pollution.

<span class="mw-page-title-main">Caliciaceae</span> Family of lichen-forming fungi

The Caliciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. Although the family has had its classification changed several times throughout its taxonomic history, the use of modern molecular phylogenetic methods have helped to establish its current placement in the order Caliciales. Caliciaceae contains 39 genera and about 670 species. The largest genus is Buellia, with around 300 species; there are more than a dozen genera that contain only a single species.

Placopsis imshaugii is a species of lichen in the family Trapeliaceae. Known from Chile, it was described as new to science in 2011. It is characterised by its distinctive rust-coloured thallus and unique morphology.

Hypotrachyna vainioi is a species of foliose lichen in the family Parmeliaceae. It is found in Brazil.

<i>Pyxine sorediata</i> Species of lichen

Pyxine sorediata, commonly known as mustard lichen, is a widely distributed species of foliose lichen in the family Caliciaceae. It has a subtropical to warm temperate distribution, and grows on bark, rocks, and moss as substrates. Pyxine sorediata has been reported from regions of North America, Europe, Africa, Asia, and Australasia.

<i>Pyxine cocoes</i> Species of lichen

Pyxine cocoes, the buttoned rosette lichen, is a widely distributed species of foliose lichen in the family Caliciaceae.

<i>Ochrolechia africana</i> Species of lichen

Ochrolechia africana, commonly known as the frosty saucer lichen, is a species of crustose and corticolous (bark-dwelling) lichen in the family Ochrolechiaceae. It is a widely distributed species, found in tropical and subtropical areas of southern Africa, Asia, Australia, North America, and South America. The lichen is characterized by the presence of a white "frosty" or powdery apothecia.

Pyxine pustulata is a species of corticolous (bark-dwelling), foliose lichen in the family Caliciaceae. Found in Botucatu, Brazil, it was formally described as a new species in 2014 by lichenologists André Aptroot and Patrícia Jungbluth. The type specimen was collected by the authors from the botanical garden on the campus of Botucatu at an altitude of 850 m (2,790 ft).

Pyxine lyei is a species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a whitish thallus that is tightly appressed to its substrate. The lobes comprising the thallus are flat, and have faint pseudocyphellae as well as patches of pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light.

Pyxine katendei is a species of corticolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a whitish to pale grey thallus that is tightly appressed to its substrate. The lobes comprising the thallus are somewhat convex; they lack pseudocyphellae, and have sparse pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light.

Pyxine lilacina is a rare species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a brownish-grey to lilac-grey thallus that is tightly appressed to its substrate. The lobes comprising the thallus are flat, and have pseudocyphellae as well as patches of pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light.

Parmotrema upretii is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. Found in India, it was described as new to science in 2003 by Pradeep Divakar. The type specimen was collected near Banjar in the Kullu district of Himachal Pradesh, India at an altitude of 1,700 m (5,600 ft), where it was found growing on rock. The species epithet honours Indian lichenologist Dalip Kumar Upreti, who collected the type specimen.

Heterodermia fragmentata is a species of corticolous (bark-dwelling) foliose lichen in the family Physciaceae. It occurs in Sri Lanka.

Cratiria sorediata is a species of corticolous (bark-dwelling), crustose lichen in the family Caliciaceae. It was first described as a new species in 2009. The type specimen was collected from Aldabra in the Seychelles.

Pyxine profallax is a species of corticolous (bark-dwelling), foliose lichen in the family Caliciaceae. It is found in Australia, Papua New Guinea, and Thailand.

Caloplaca akbarica, a species of lichen saxicolous (rock-dwelling), crustose lichen described in 2002. Found in Tajikistan, it has a rosette-shaped, lobate thallus, and apothecia that are distinctly pruinose. It was formally described as a new species in 2002 by the lichenologists Imomnazar Kudratov and Oleksandr Khodosovtsev.

Hanstrassia lenae is a species of saxicolous (rock-dwelling) in the family Teloschistaceae. Described as a new species in 2007, the lichen is found in Russian Far East, Mongolia, and Siberia. It closely resembles Elenkiniana ehrenbergii but distinguished by the presence of soralia on its thallus. This species has a thick, effigurate thallus with weak marginal lobes and developed marginal, labriform (lip-shaped) soralia.

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<i>Pyxine petricola</i> Species of lichen

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References

  1. 1 2 "Synonymy: Pyxine subcinerea Stirt". Species Fungorum . Retrieved 21 February 2021.
  2. ↑ Stirton, J. (1897). "A new classification of the genus Pyxine". Transactions of the New Zealand Institute. 30: 393–398.
  3. ↑ Knight, C. (1882). "Contributions to the Lichenographia of New South Wales". Transactions of the Linnean Society of London. 2nd Series. 2: 37–51.
  4. ↑ Vainio, E.A. (1915). "Additamenta ad lichenographiam Antillarum illustrandum". Annales Academiae Scientiarum Fennicae (in Latin). 6 (7): 71.
  5. ↑ Müller, J. (1879). "Lichenologische Beiträge IX". Flora (Regensburg) (in Latin). 62 (19): 289–298.
  6. ↑ Nylander, W. (1869). Synopsis Methodica Lichenum Omnium hucusque Cognitorum, Praemissa Introductione Lingua Gallica (in Latin). Vol. 2. p. 2.
  7. ↑ Imshaug, H.A. (1957). "The lichen genus Pyxine in North and Middle America". Transactions of the American Microscopical Society. 76 (3): 246–269. doi:10.2307/3223889. JSTOR   3223889.
  8. 1 2 3 4 5 6 Elix, John Alan (2009). "Physciaceae". Flora of Australia. Vol. 57. Canberra & Melbourne: CSIRO Publishing. p. 532. ISBN   978-0-643-09664-6.
  9. ↑ Modenesi, P.; Bombardi, V.; Giordani, P.; Brunialti, G.; Corallo, A. (2007). "Dissolution of weddellite, calcium oxalate dihydrate, in Pyxine subcinerea". The Lichenologist. 33 (3): 261–266. doi:10.1006/lich.2001.0321. S2CID   83716323.
  10. 1 2 3 4 5 Moberg, R. (1983). "Studies on Physciaceae (Lichens) II. The genus Pyxine in Europe". The Lichenologist. 15 (2): 161–167. doi:10.1017/S0024282983000250.
  11. 1 2 3 Amtoft, Anja (2002). "Pyxine subcinerea in the Eastern United States" (PDF). The Bryologist. 105 (2): 270–272. doi:10.1639/0007-2745(2002)105[0270:PSITEU]2.0.CO;2.
  12. ↑ Bock, Christina; Hauck, Markus; Fischer, Eberhard (2007). "The lichen flora of Rwanda: an annotated checklist". Willdenowia. 37 (2): 563–575. doi: 10.3372/wi.37.37216 . S2CID   84822147.
  13. ↑ Yang, Mei-Xia; Wang, Xin-Yu; Liu, Dong; Zhang, Yan-Yun; Li, Li-Juan; Yin, An-Cheng; Scheidegger, Christoph; Wang, Li-Song (2019). "New species and records of Pyxine (Caliciaceae) in China". MycoKeys. 45 (45): 93–109. doi: 10.3897/mycokeys.45.29374 . PMC   6363720 . PMID   30733639.
  14. ↑ Hayward, Bruce W.; Hayward, Glenys C. (1990). "Lichens of Whale (Motuhora) and Rurima Islands, Bay of Plenty, New Zealand" (PDF). Tane. 32: 61–71.
  15. ↑ Shukla, Vertika; Upreti, Dalip K. (2007). "Effect of metallic pollutants on the physiology of lichen, Pyxine subcinerea Stirton in Garhwal Himalayas". Environmental Monitoring and Assessment. 141 (1–3): 237–243. doi:10.1007/s10661-007-9891-z. PMID   17879139. S2CID   1325600.
  16. ↑ Shukla, Vertika; Upreti, Dalip K. (2010). "Changing lichen diversity in and around urban settlements of Garhwal Himalayas due to increasing anthropogenic activities". Environmental Monitoring and Assessment. 174 (1–4): 439–444. doi:10.1007/s10661-010-1468-6. PMID   20440642. S2CID   33101795.
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