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.
Description
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 peduncles (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]
Muehlenbeckia is placed in the tribe Polygoneae of the subfamily Polygonoideae. Within the tribe, it is most closely related to the genera Reynoutria and Fallopias.s., forming the so-called "RMF clade".[6]
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]
References
^ abcdef"Muehlenbeckia Meisn". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-03-06.
^Freeman, Craig C. "Muehlenbeckia". In Flora of North America Editorial Committee (ed.). Flora of North America (online). eFloras.org. Retrieved 2019-03-16.
^Meisner, C.F. (1841). "Mühlenbeckia". Plantarum Vascularium Genera. Vol. 2. pp. 227–228. Retrieved 2019-03-17.
^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. Vol. 3 (Lh–O) (2nd ed.). Utrecht: Bohn, Scheltema & Holkema. p. 614. ISBN90-313-0444-1. Retrieved 2019-03-17.
^ abcSchuster, 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.
^"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 links
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