Patellifolia

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Ordo: Caryophyllales

Familia: Amaranthaceae s.l.
Cladus: Chenopodiaceae s.str.
Subfamilia: Betoideae
Tribus: Hablitzieae
Genus: Patellifolia

Species: P. patellaris – P. procumbens – P. webbiana

genus formerly often included in Beta (still in Hassler 2018). Deep genetic differentiation revealed by Kadereit et al. (2006) and Romeiras et al. (2016).
Thulin et al. (2010) proposed to treat all members of Patellifolia as a single variable species, Patellifolia procumbens s.l.
Romeiras et al. (2016) give reasons for 3 distinct species.

Name

Patellifolia A.J.Scott, Ford-Lloyd & J.T. Williams, Taxon 26(2–3): 284. (1977)

Type: Patellifolia webbiana (Moq.) A.J.Scott, Ford-Lloyd & J.T. Williams

Synonyms

Patellaria J.T. Williams, A.J.Scott & Ford-Lloyd, Feddes Repert. 87(5): 289. (1976), nom. illeg., (later homonym, non Patellaria Hoffmann 1789, Lichenes), replaced by Patellifolia
Type: Patellaria webbiana (Moq.) J.T. Williams, A.J.Scott & Ford-Lloyd
Beta sect. Procumbentes Ulbr., Nat. Pflanzenfam., ed. 2 [Engler & Prantl] 16c: 455. (1934)
Type: Beta procumbens C.Sm.
Beta "Patellares" Transhel (1927), informal group, unranked
Type: Beta patellaris Moq.

References
Primary references

Scott, A.J., Ford-Lloyd, B.V. & Williams, J.T. 1977. Patellifolia, nomen novum (Chenopodiaceae). Taxon 26(2–3): 284. Reference page.
Williams, J.T., Scott, A.J. & Ford-Lloyd, B.V. 1976. Patellaria: A new genus in the Chenopodiaceae. Feddes Repertorium 87: 289–292. DOI: 10.1002/fedr.19760870502 Reference page. : 289
Ulbrich, O.E. 1934. Chenopodiaceae, in: Engler, A. & Prantl, K.A.E. (eds.): Die natürlichen Pflanzenfamilien, ed.2. 16c, Engelmann, Leipzig: 379–584. Reference page. : 455.
Transhel, W.A. 1927. Obzor vida roda Beta. Trudy po Prikladnoj Botanike, Genetike i Selekcii. 17: 203–223. Reference page.

Additional references

Kadereit, G., Hohmann, S. & Kadereit, J.W. 2006. A synopsis of Chenopodiaceae subfam. Betoideae and notes on the taxonomy of Beta. Willdenowia 36: 9–19. DOI: 10.3372/wi.36.36101. Reference page.
Romeiras, M.M., Vieira, A., Silva, D.N., Moura, M., Santos-Guerra, A., Batista, D., Duarte, M.C., & Paulo, O.S. 2016. Evolutionary and Biogeographic Insights on the Macaronesian Beta-Patellifolia Species (Amaranthaceae) from a Time-Scaled Molecular Phylogeny. PLoS One. 2016; 11(3): e0152456. DOI: 10.1371/journal.pone.0152456 Reference page.
Thulin, M., Rydberg, A., & Thiede, J. 2010. Identity of Tetragonia pentandra and taxonomy and distribution of Patellifolia (Chenopodiaceae). Willdenowia 40(1): 5–11. DOI: 10.3372/wi.40.40101 Reference page.

Links

Hassler, M. 2018. Patellifolia. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2018. Species 2000 & ITIS Catalogue of Life. Published on the internet. Accessed: 2018 May 29. Reference page.
International Plant Names Index. 2016. Patellifolia. Published online. Accessed: August 16 2016.
The Plant List 2013. Patellifolia in The Plant List Version 1.1. Published on the internet. Accessed: 2016 August 16.
Tropicos.org 2016. Patellifolia. Missouri Botanical Garden. Published on the internet. Accessed: 16 August 2016.
Global Biodiversity Information Facility. 2019. GBIF Backbone Taxonomy. Checklist dataset. Taxon: Patellifolia. .

Patellifolia is a genus of flowering plants in the subfamily Betoideae of the family Amaranthaceae. These are mostly procumbent herbs occurring in the Western Mediterranean region and Macaronesia, with some isolated occurrences in North Africa and at the Horn of Africa. They are interesting as crop wild relatives of sugar beet.

Description
Inflorescence of Patellifolia procumbens
Fruit of Patellifolia patellaris

Patellifolia are annual or perennial herbs, growing erect or often procumbent. The alternate leaves have a petiole, their leaf blade is heart-shaped or hastate.[2]

The spike-like inflorescences consist of glomerules of one to three flowers sitting in the axils of leaf-like bracts. The free flowers are hermaphrodite. The perianth consists of five herbaceous, slightly keeled tepal lobes which are connate at base. There are five stamens opposite to the tepals, their filaments are fused at base forming a disc. The ovary is semi-inferior with 2 stigmas.[2]

In fruit, the ovary is partly immersed in the enlarged base of the perianth. The tepal lobes are not modified and appressed to the fruit.[1] The solitary fruits are nearly globular capsules, they fall down when ripe and open with a circumscissile lid. The vertical seed contains an annular embryo and copious perisperm (feeding tissue).[2]
Distribution and habitat

Patellifolia is mainly distributed in the Western Mediterranean region (Spain, Morocco), Macaronesia and Cape Verde Islands. There are also some isolated occurrences in North Africa (Hoggar Mountains and Tassili n'Ajjer, Libya), and in the Horn of Africa region (Socotra, Somalia).[3]

The plants grow in more or less coastal habitats from sea level up to 200 m, in Macaronesia and the Western Mediterranean region, and also in Socotra. But in the North African mountains they were found at higher altitudes up to 2000 m, and also in Somalia at 1150 m.[3]
Systematics
Patellifolia patellaris
Patellifolia procumbens
Patellifolia webbiana

The genus Patellifolia was published in 1977 by A J Scott, Brian V. Ford-Lloyd and J. Trevor Williams, with the type species Patellifolia webbiana.[4] The same authors had described this taxon already in 1976 as Patellaria J.T. Williams, A.J.Scott & Ford-Lloyd, but that was an illegitimate name, (because the lichen genus Patellaria Hoffmann was published earlier in 1789).[5]

These plants were first grouped together in 1927 by Vladimir Andreevich Tranzschel as an informal unranked taxon Patellares in the genus Beta. In 1934, Oskar Eberhard Ulbrich placed them in a new section Beta sect. Procumbentes.[6] Until 2006, Patellifolia was often not accepted as a separate genus. But recent molecular genetic studies by Kadereit et al. (2006) and Romeiras et al. (2016) revealed a deep genetic differentiation between Beta and Patellifolia and confirmed the status as own genus.[1][7]

Patellifolia comprises one to three species:

Patellifolia patellaris (Moq.) A.J. Scott & al. (Syn. Beta patellaris Moq.), in dry coastal sites or on rocks, widely distributed in Macaronesia (Canary Islands, Madeira, Cape Verde) and in the western Mediterranean (Spain, Balearic islands, Sicily, Morocco), North Africa,[7] to the Horn of Africa.[3]
Patellifolia procumbens (Chr. Sm.) A.J. Scott & al. (Syn. Beta procumbens Chr. Sm.), in dry coastal sites in Macaronesia (Canary Islands, Madeira, Cape Verde).[7]
Patellifolia webbiana (Moq.) A.J. Scott & al. (Syn. Beta webbiana Moq.), endemic on Gran Canaria, in ruderal nitrophilous sites,[7] Critically Endangered.[8]

It was suggested that Patellifolia procumbens and Patellifolia webbiana might not be different species.[8] The identification of the three species is difficult, and some distinguishing characters were found to be unreliable. Therefore, Thulin et al. (2010) proposed to treat all members of Patellifolia as a single variable species, Patellifoia procumbens.[3] This proposal was followed in the Euro+Med Plant Base.[9]

But Patellifolia patellaris could not be hybridised with the other two species, supporting the rank of an own species.[1] The island species evolved recently, and because of their isolation they developed only small genetic differentiation. As a result, they show only weak genetic barriers to hybridization.[7]
Evolution

Patellifolia is a rather old genus;[1] the divergence from its sister genus Beta probably occurred early in the Late Oligocene.[7] Its subtaxa are relatively young, diversifying in the late Pliocene or early Quaternary.[1][7] The present distribution area suggests that it was previously a widespread taxon, but later the area fragmented and extensive extinctions occurred.[3]
Crop wild relatives

Patellifolia is related to the economically important cultivated beets (Beta vulgaris subsp. vulgaris, with sugar beet, beetroot, chard and fodder beet). Therefore, Patellifolia is of great interest as Crop wild relative and potential gene donor.[7] They seem to be resistant to some of the most serious diseases of sugar beets, to leaf spot disease caused by Cercospora beticola, curly top virus, rhizomania, and powdery mildew (Erysiphe polygoni).[7] All three species proved to be highly resistant to the Beet cyst eelworm (Heterodera schachtii). The three species differ in their resistance level, whereas Patellifolia patellaris is not completely immune, but eelworms never develop to maturity in the other two species.[1]
References

Kadereit, G., Hohmann, S. & Kadereit, J.W. (2006). "A synopsis of Chenopodiaceae subfam. Betoideae and notes on the taxonomy of Beta". - Willdenowia 36, p. 9-19.
Bolibar, S.C.: Patellifolia in Flora Iberica p.482-484., accessed 20 August 2016.
Thulin, M.; Rydberg, A.; Thiede, H. (2010). "Identity of Tetragonia pentandra and taxonomy and distribution of Patellifolia (Chenopodiaceae)". Willdenowia 40(1): 5-11. doi:10.3372/wi.40.40101
Scott, A.J., Ford-Lloyd, B.V. & Williams, J.T. (1977). "Patellifolia, nomen novum (Chenopodiaceae)". Taxon 26(2–3): 284. doi:10.2307/1220567
"Patellaria J.T. Williams & Ford-Lloyd ex J.T. Williams, A.J. Scott & Ford-Lloyd Synonym". Tropicos. Missouri Botanical Garden.
Ulbrich, O.E. (1934). "Chenopodiaceae", in: Engler, A. & Prantl, K.A.E. (eds.): "Die natürlichen Pflanzenfamilien", ed.2 16c, Engelmann, Leipzig: 455.
Romeiras, M.M., Vieira, A., Silva, D.N., Moura, M., Santos-Guerra, A., Batista, D., Duarte, M.C., & Paulo, O.S. (2016). "Evolutionary and Biogeographic Insights on the Macaronesian Beta-Patellifolia Species (Amaranthaceae) from a Time-Scaled Molecular Phylogeny." PLoS One. 2016; 11(3): e0152456. doi:10.1371/journal.pone.0152456
Santos-Guerra, A.; Frese, L. (2011). Patellifolia webbiana. The IUCN Red List of Threatened Species 2011: e.T172260A6859581. doi:10.2305/IUCN.UK.2011-1.RLTS.T172260A6859581.en. Accessed 19 August 2016.
Uotila, P. (2011): Patellifolia. In: "Chenopodiaceae (pro parte majore)." In: Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity.