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Muehlenbeckia or maidenhair is a genus of flowering plants in the family Polygonaceae. It is native to the borders of the Pacific, including South and North America, Papua New Guinea and Australasia. It has been introduced elsewhere, including Europe.[1] Species vary in their growth habits, many being vines or shrubs. In some environments, rampant species can become weedy and difficult to eradicate.

Muehlenbeckia
Muehlenbeckia adpressa - Curtis.jpg
Muehlenbeckia adpressa
Scientific classification e
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Polygonaceae
Subfamily: Polygonoideae
Genus: Muehlenbeckia
Meisn.[1]
Synonyms[1]
  • Calacinum Raf
  • Homalocladium (F. Muell.) L. H. Bailey

Contents

DescriptionEdit

Species of Muehlenbeckia vary considerably in their growth habits; they may be perennials, vinelike, or shrubs. All have rhizomatous roots. Their leaves are arranged alternately on the stem, usually with stalks (petioles), but sometimes stalkless (sessile). The brownish ocrea is short and tubular, soon disintegrating. The inflorescences may be terminal or axillary, and are in the form of spikes or clusters, with at most very short peduncules (flowering stems). Individual flowers have pedicels (stalks). The flowers may be bisexual or unisexual, with sometimes a mixture of staminate, pistillate and bisexual flowers on the same plant. There are five white to greenish white tepals, joined at the base. Staminate flowers have 8 (sometimes 9) stamens and a rudimentary pistil. Pistillate flowers have rudimentary stamens and three spreading styles. The fruit is in the form of a black or dark brown unwinged achene, three-sided to more or less globe-shaped, at least partly enclosed by the persistent tepals.[2][3]

TaxonomyEdit

The genus was erected by Carl Meissner in 1841,[1] initially for two species that he distinguished from Coccoloba and Polygonum.[4] The generic name honours Alsatian bryologist Heinrich Gustav Mühlenbeck (1798–1845).[5]

Muehlenbeckia is placed in the tribe Polygoneae of the subfamily Polygonoideae. Within the tribe, it is most closely related to the genera Reynoutria and Fallopia s.s., forming the so-called "RMF clade".[6]

Polygoneae

Knorringia

Polygonum ciliinode (syn. Fallopia ciliinodis)

DAP clade

Duma

Atraphaxis

Polygonum

RMF clade

Reynoutria

Muehlenbeckia

Fallopia s.s.

SpeciesEdit

As of March 2019, Plants of the World Online recognized 24 species (see note below):[1]

Some sources, including Plants of the World Online, regard M. adpressa as a synonym of M. australis.[1] Others treat them as separate species.[7]

Three species have been transferred to the genus Duma:[8]

DistributionEdit

InvasivenessEdit

All members of the RMF clade appear to have the potential to become invasive, in some cases via vigorous hybrids. The highly invasive Japanese knotweed (Reynoutria japonica) hybridizes with Muehlenbeckia australis.[6] The related Muehlenbeckia complexa has established populations in southern parts of Britain and in the Channel Islands,[6] and is a problematic invasive species in the San Francisco area.[9][10]

ReferencesEdit

  1. ^ a b c d e f "Muehlenbeckia Meisn.". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-03-06.
  2. ^ Freeman, Craig C. "Muehlenbeckia". In Flora of North America Editorial Committee (ed.). Flora of North America (online). eFloras.org. Retrieved 2019-03-16.
  3. ^ National Herbarium of New South Wales. "Genus Muehlenbeckia". New South Wales FloraOnline. Royal Botanic Garden, Sydney. Retrieved 2008-05-03.
  4. ^ Meisner, C.F. (1841). "Mühlenbeckia". Plantarum Vascularium Genera. 2. pp. 227–228. Retrieved 2019-03-17.
  5. ^ Stafleu, Frans A. & Cowan, Richard S. (1981). "Muehlenbeck, Heinrich Gustav". Taxonomic Literature: a Selective Guide to Botanical Publications and Collections with Dates, Commentaries and Types. 3 (Lh–O) (2nd ed.). Utrecht: Bohn, Scheltema & Holkema. p. 614. ISBN 90-313-0444-1. Retrieved 2019-03-17.
  6. ^ a b c Schuster, Tanja M.; Reveal, James L.; Bayly, Michael J. & Kron, Kathleen A. (2015). "An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia". Taxon. 64 (6): 1188–1208. doi:10.12705/646.5.
  7. ^ "Vascular Plants: Muehlenbeckia adpressa". Australian Plant Name Index (APNI). Retrieved 2019-03-06.
  8. ^ "Duma T.M.Schust.". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-03-04.
  9. ^ Obscure Weeds Discussion Group. "2006 Cal-IPC Symposium" (PDF). Archived from the original (PDF) on 2016-10-26.
  10. ^ "Mattress Wire Weed Control Study, The Presidio Trust of San Francisco". Habitat Restoration Projects. May and Associates Inc. Archived from the original on 2005-04-22.

External linksEdit