# Collema

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Genus of lichens

Collema Collema flaccidum Scientific classification Kingdom: Fungi Division: Ascomycota Class: Lecanoromycetes Order: Peltigerales Family: Collemataceae Genus: Collema Weber ex F.H.Wigg. (1780) Type species Collema lactuca (Weber) Weber ex F.H.Wigg. (1780) Synonyms[1] List Chiastosporum Dughi (1956) Collema P.Browne (1756) Collema sect. Collemodiopsis Vain. (1890) Collema sect. Eucollema Tuck. (1872) Collema subgen. Lathagrium Ach. (1810) Collematomyces E.A.Thomas ex Cif. & Tomas. (1953) Collemis Clem. (1931) Collemodiopsis (Vain.) B.de Lesd. (1910) Dicollema Clem. (1909) Eucollema (Tuck.) Horw. (1912) Kolman Adans. (1763) Synechoblastus Trevis. (1853) Tichodea Körb. (1848)

***Collema*** (**jelly lichen**) is a [genus](/source/Genus) of [lichens](/source/Lichen) in the [family](/source/Family_(taxonomy)) [Collemataceae](/source/Collemataceae).[2] The [photobiont](/source/Photobiont) is the [cyanobacterium](/source/Cyanobacterium) genus *[Nostoc](/source/Nostoc)*.[3] Species in this genus typically grow on nutrient-rich bark or somewhat siliceous or calcareous rocks in humid environments.[4]

## Description

Collema lichens are characterized by their medium to large size, with a diameter of 3 to 20 cm (1 to 8 in). They have a [leaf-like](/source/Foliose_lichen), membranous structure that does not swell noticeably when wet. The upper surface of the [thallus](/source/Thallus) is dark olive-green to brown-black and is not hairy. The [lobes](/source/Glossary_of_lichen_terms#lobes) are 2 to 15 mm broad, rounded, and usually flat or partially raised, with smooth or [pustulate](/source/Glossary_of_lichen_terms#pustulate) surfaces adorned with elongated ridges or folds.[4]

Both upper and lower [cortex](/source/Glossary_of_lichen_terms#cortex) are absent in *Collema*, and the photobiont *[Nostoc](/source/Nostoc)* forms chains of cells throughout the thallus without creating a separate [layer](/source/Glossary_of_lichen_terms#photobiont_layer). [Isidia](/source/Isidia) can be present or absent, while [soredia](/source/Soredia) are not found in this genus. The reproductive structures, known as [apothecia](/source/Apothecia), have a pale brown to red-brown [disc](/source/Glossary_of_lichen_terms#disc) that can be flat or convex. The [thalline margin](/source/Glossary_of_lichen_terms#thalline_margin) is whole and sometimes displays isidia.[4]

The [true exciple](/source/Glossary_of_lichen_terms#true_exciple) consists of cells that can be either uniformly sized or elongated. The [epithecium](/source/Glossary_of_lichen_terms#epithecium) is indistinct and can be colourless or pigmented, while the [hymenium](/source/Hymenium) is colorless and turns blue when treated with [iodine](/source/Iodine). A more or less colourless [hypothecium](/source/Glossary_of_lichen_terms#hypothecium) is also present. The [hamathecium](/source/Glossary_of_lichen_terms#hamathecium) comprises paraphyses that separate in a solution of [potassium hydroxide](/source/Potassium_hydroxide) and may be unbranched or branched, often connecting near their tips, which can be club-shaped or round and exhibit a yellowish to reddish-brown hue.[4]

The [asci](/source/Ascus) are club-shaped (clavate) with a strongly thickened apex, and both the [apical dome](/source/Glossary_of_lichen_terms#apical_dome) and the downwardly projecting annulus and apical cap react blue to iodine. Each ascus produces eight spores that are narrowly [ellipsoidal](/source/Ellipsoid) to spindle-shaped or nearly cylindrical with transverse [septa](/source/Septum). [Conidiomata](/source/Glossary_of_lichen_terms#conidiomata), or [pycnidia](/source/Glossary_of_lichen_terms#pycnidia), are immersed within the thallus and can be located on the margins or lamina with a pale [ostiole](/source/Ostiole). The [conidia](/source/Glossary_of_lichen_terms#conidia) are rod-shaped with a slightly enlarged apex. No [lichen products](/source/Lichen_product) have been detected in *Collema* using [thin-layer chromatography](/source/Thin-layer_chromatography).[4]

## Species

As of April 2023[\[update\]](https://en.wikipedia.org/w/index.php?title=Collema&action=edit), [Species Fungorum](/source/Species_Fungorum) (in the [Catalogue of Life](/source/Catalogue_of_Life)) accepts 24 species of *Collema*.[2]

*Collema subconveniens*

*Collema subflaccidum*

- *[Collema actinoptychum](https://en.wikipedia.org/w/index.php?title=Collema_actinoptychum&action=edit&redlink=1)* Nyl. (1868)[5]

- *[Collema coniophilum](/source/Collema_coniophilum)* Goward (2009)[6] – Canada

- *[Collema flaccidum](/source/Collema_flaccidum)* (Ach.) Ach. (1810)

- *[Collema furfuraceum](https://en.wikipedia.org/w/index.php?title=Collema_furfuraceum&action=edit&redlink=1)* (Schaer.) Du Rietz (1929)

- *[Collema glaucophthalmum](https://en.wikipedia.org/w/index.php?title=Collema_glaucophthalmum&action=edit&redlink=1)* Nyl. (1858)[7]

- *[Collema glebulentum](https://en.wikipedia.org/w/index.php?title=Collema_glebulentum&action=edit&redlink=1)* (Nyl. ex Cromb.) Degel. (1952)

- *[Collema implicatum](https://en.wikipedia.org/w/index.php?title=Collema_implicatum&action=edit&redlink=1)* Nyl. (1863)[8]

- *[Collema insulare](https://en.wikipedia.org/w/index.php?title=Collema_insulare&action=edit&redlink=1)* Degel. (1974)

- *[Collema japonicum](https://en.wikipedia.org/w/index.php?title=Collema_japonicum&action=edit&redlink=1)* (Müll.Arg.) Hue (1898)

- *[Collema laeve](https://en.wikipedia.org/w/index.php?title=Collema_laeve&action=edit&redlink=1)* Hook.f. & Taylor (1844)

- *[Collema leptaleum](https://en.wikipedia.org/w/index.php?title=Collema_leptaleum&action=edit&redlink=1)* Tuck. (1866)[9]

- *[Collema leucocarpum](https://en.wikipedia.org/w/index.php?title=Collema_leucocarpum&action=edit&redlink=1)* Hook.f. & Taylor (1844)

- *[Collema marginale](https://en.wikipedia.org/w/index.php?title=Collema_marginale&action=edit&redlink=1)* (Huds.) Hoffm. (1794)

- *[Collema nigrescens](/source/Collema_nigrescens)* (Huds.) DC. (1805)

- *[Collema pulcellum](https://en.wikipedia.org/w/index.php?title=Collema_pulcellum&action=edit&redlink=1)* Ach. (1814)

- *[Collema pustulatum](https://en.wikipedia.org/w/index.php?title=Collema_pustulatum&action=edit&redlink=1)* Ach. (1814)

- *[Collema rugosum](https://en.wikipedia.org/w/index.php?title=Collema_rugosum&action=edit&redlink=1)* Kremp. (1870)

- *[Collema ryssoleum](https://en.wikipedia.org/w/index.php?title=Collema_ryssoleum&action=edit&redlink=1)* (Tuck.) A.Schneid. (1872)

- *[Collema sichuanense](https://en.wikipedia.org/w/index.php?title=Collema_sichuanense&action=edit&redlink=1)* H.J.Liu & J.C.Wei (2003))[10] – China

- *[Collema subconveniens](/source/Collema_subconveniens)* Nyl. (1888)

- *[Collema subflaccidum](https://en.wikipedia.org/w/index.php?title=Collema_subflaccidum&action=edit&redlink=1)* Degel. (1974)[11]

- *[Collema subnigrescens](https://en.wikipedia.org/w/index.php?title=Collema_subnigrescens&action=edit&redlink=1)* Degel. (1954)[12]

- *[Collema substipitatum](https://en.wikipedia.org/w/index.php?title=Collema_substipitatum&action=edit&redlink=1)* Zahlbr. (1930)

## References

1. **[^](#cite_ref-Species_Fungorum_synonymy_1-0)** ["Synonymy: *Collema* Weber ex F.H. Wigg., Prim. fl. holsat. (Kiliae): 89 (1780)"](http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=1175). [Species Fungorum](/source/Species_Fungorum). Retrieved 2 April 2021.

1. ^ [***a***](#cite_ref-CoL_2-0) [***b***](#cite_ref-CoL_2-1) ["*Collema*"](https://www.catalogueoflife.org/data/taxon/3SBC). *[Catalogue of Life](/source/Catalogue_of_Life)*. [Species 2000](/source/Species_2000): Leiden, the Netherlands. Retrieved 19 April 2023.

1. **[^](#cite_ref-dobson_3-0)** Dobson, F.S. (2000) Lichens, an illustrated guide to the British and Irish species. 4th edition. Richmond publishing Co., Slough, England.

1. ^ [***a***](#cite_ref-Cannon_et_al._2020_4-0) [***b***](#cite_ref-Cannon_et_al._2020_4-1) [***c***](#cite_ref-Cannon_et_al._2020_4-2) [***d***](#cite_ref-Cannon_et_al._2020_4-3) [***e***](#cite_ref-Cannon_et_al._2020_4-4) Cannon, Paul; Otálora, Mónica A.G.; Košuthová, Alica; Wedin, Mats; Aptroot, André; Coppins, Brian; Simkin, Janet (2020). "Peltigerales: Collemataceae, including the genera *Blennothallia*, *Callome*, *Collema*, *Enchylium*, *Epiphloea*, *Lathagrium*, *Leptogium*, *Pseudoleptogium*, *Rostania* and *Scytinium*". *Revisions of British and Irish Lichens*. **2**: 1–38 [12]. [doi](/source/Doi_(identifier)):[10.34885/174](https://doi.org/10.34885%2F174).

1. **[^](#cite_ref-Nylander_1868_5-0)** Nylander, W. (1867). ["Synopsis lichenum Novae Caledoniae"](https://www.biodiversitylibrary.org/page/9711876). *Bulletin de la Société Linnéenne de Normandie*. 2 (in Latin) (2): 39–140 [43].

1. **[^](#cite_ref-Spribille_et_al._2009_6-0)** Spribille, Toby; Björk, Curtis R.; Ekman, Stefan; Elix, John A.; Goward, Trevor; Printzen, Christian; Tønsberg, Tor; Wheeler, Tim (2009). "Contributions to an epiphytic lichen flora of northwest North America: I. Eight new species from British Columbia inland rain forests". *The Bryologist*. **112** (1): 109–137. [doi](/source/Doi_(identifier)):[10.1639/0007-2745-112.1.109](https://doi.org/10.1639%2F0007-2745-112.1.109). [S2CID](/source/S2CID_(identifier)) [84225966](https://api.semanticscholar.org/CorpusID:84225966).

1. **[^](#cite_ref-Nylander_1858_7-0)** Nylander, W. (1858). ["Lichenes collecti in Mexico a Fr. Müller"](https://www.biodiversitylibrary.org/page/51418). *Flora (Regensburg)* (in Latin). **41**: 377–386.

1. **[^](#cite_ref-Nylander_1863_8-0)** Nylander, W. (1863). ["Lichenographia Novogranatensis prodromus"](https://www.biodiversitylibrary.org/page/13599173). *Acta Societatis Scientiarum Fennicae* (in Latin). **7** (2): 415–504.

1. **[^](#cite_ref-Tuckerman_1864_9-0)** Tuckerman, E. (1864). ["Observations on North American and other lichens"](https://www.biodiversitylibrary.org/page/3097429). *Proceedings of the American Academy of Arts and Sciences*. **6**: 263–287.

1. **[^](#cite_ref-Liu_&_Wei_2003_10-0)** Liu, H.J.; Wei, J.C. (2003). "Two new taxa of the lichen genus *Collema* from China". *Mycosystema*. **22** (4): 531–533.

1. **[^](#cite_ref-Degelius_1974_11-0)** [Degelius, G.](/source/Gunnar_Degelius) (1974). *The lichen genus*Collema*with special reference to the extra-European species*. Symbolae Botanicae Upsalienses. Vol. 20. p. 140.

1. **[^](#cite_ref-Degelius_1954_12-0)** Degelius, G. (1954). *The lichen genus*Collema*in Europe*. Symbolae Botanicae Upsalienses. Vol. 13. p. 413.

Taxon identifiers Collema Wikidata: Q150980 Wikispecies: Collema APNI: 129770 AusFungi: 60015965 AusLichen: 30017297 CoL: 3SBC EoL: 16598 EPPO: 1CLEMG FloraBase: 27451 GBIF: 7237642 iNaturalist: 117962 IndexFungorum: 1175 ITIS: 191331 MycoBank: 1175 NBN: BMSSYS0000043973 NCBI: 203431 NZOR: ecb9b02c-d577-44dd-88ff-6470ca5cc0b3 Open Tree of Life: 633250 PLANTS: COLLE2 SpeciesFungorum: 1175

Authority control databases National Israel Other Yale LUX

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Adapted from the Wikipedia article [Collema](https://en.wikipedia.org/wiki/Collema) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Collema?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.