Alternanthera philoxeroides

Alligator weed ( Alternanthera philoxeroides )

The alligator weed ( Alternanthera philoxeroides ) is a flowering plant in the family Amaranthaceae ( Amaranthaceae ). These aquatic and marsh plant is native to South America. It applies in many areas of the world as an invasive plant.

• 4.1 Notes and references

Description

Appearance and leaf

The Alligator weed grows as a perennial herbaceous plant. They thrive as water and marsh plants aquatic to semi- terrestrial and form up to 5 meters long, creeping stolons and forms so often mats. The hollow stems are 55-120 cm long and branched. Young stems and the leaf axils are hairy white and older stems are bare.

The constantly against the stem arranged leaves are petiolate or sessile. When a petiole is present then it is 3 to 10 mm long and hairy hairless or slightly. The herbaceous, simple leaf blade is at a length of 2.5 to 7 cm and a width of 0.5 to 2 cm more or less narrowly elliptic, lanceolate wrong, oblong, oblong- obovate or ovate - lanceolate with verschmälertem Spreitengrund as well as acute or obtuse upper end which is mucronate. The Spreitenrand is smooth. The leaf surface is glabrous or ciliate and the leaf surface is hairy bristly.

Inflorescences and flowers

The alligator weed blooms in the warm season, for example, in China from May to October. Most laterally or terminally on Blütenstandsschäften are rarely spherical inflorescences with a diameter from 0.8 to 1.7 cm. The membranous and durable support and cover sheets are white and have a pointed upper end. The bracts are ovate with a length of 2 to 2.5 mm less than half as long as the bloom as well. The cover sheets are lanceolate with a length of about 2 mm.

The hermaphrodite flowers are radial symmetry. The same five, white, shiny, membranous bracts are lanceolate or oblong bald with a pointed upper end at a length of 5 to 6 mm. There are five stamens present. The 2.5 to 3 mm long stamens are fused cup-shaped at their base. The oblong- lineal or tongue-shaped Pseudostaminodien are about as long as the stamens. The Short-stalked ovary is ovoid and flattened.

Propagation

Fruits and seeds were not observed on samples outside the area of origin; one suspects that they, at least exclusively vegetatively propagate the neophytic stocks.

Chromosome number

The chromosome number is 2n = 100

Occurrence

The wide original South American distribution area of Alternanthera philoxeroides includes French Guiana, Guyana, Suriname, Venezuela, Brazil, Bolivia, Peru, northern Argentina, Paraguay and Uruguay. The Alligator weed has spread to many parts of the world as a neophyte and applies in Australia, China, Taiwan, New Zealand, Thailand, the Caribbean islands and the United States as an invasive plant.

The Alligator weed is grown in central China, Java, Kalimantan and Louisiana.

Taxonomy

This species was in 1825 under the name ( basionym ) Bucholzia philoxeroides by Carl Friedrich Philipp von Martius in Novorum Actorum Academiae Caesareae Leopoldinae - Carolinae Naturae Curiosorum, Volume 13 (1 ), pp. 107 firstdescribed. August Grisebach she put 1879 in Proceedings of the Royal Society of Sciences in Göttingen, Volume 24, page 36 in the genus Alternanthera. Other synonyms for Alternanthera philoxeroides ( Mart. ) Griseb. are: Achyranthes philoxeroides ( Mart. ) Standlschmaus, Alternanthera philoxeroides fo. . angustifolia Suess. , Alternanthera philoxeroides var acutifolia ( Mart. ) Hicken, Alternanthera philoxeroides var lancifolia Chodat, Alternanthera philoxeroides var luxurians Suess. , Alternanthera philoxeroides var obtusifolia ( Mart. ) Hicken, Bucholzia philoxeroides var acutifolia Mart. , Bucholzia philoxeroides var obtusifolia Mart. , Telanthera philoxeroides ( Mart. ) Moq. , Telanthera philoxeroides var acutifolia ( Mart. ) Moq. , Telanthera philoxeroides var denticulata Seub. in C.Martius, Telanthera philoxeroides var linearifolia Chodat, Telanthera philoxeroides var obtusifolia ( Mart. ) Moq. , Telanthera philoxeroides var obtusifolia Moq. , Telanthera philoxeroides var phyllantha Seub. in C.Martius. The specific epithet philoxeroides is derived from the Greek words from phil ( o), " plex " for dry and " oid " for " the shape as " a possible interpretation is about this kind of " looks like a plant from country ".

Swell

• Bojian Bao, Thomas Borsch & Steven E. Clemants: Amaranthaceae: Alternanthera philoxeroides, S. 426 - the same text online as well as printed work, in: Wu Zhengyi, Peter H. Raven & Deyuan Hong (eds.): Flora of China, Volume 5 - Ulmaceae through Basellaceae, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, December 19, 2003, ISBN 1-930723 X -27. ( Description section )
• Steven E. Clemants: Alternanthera in the Flora of North America, Volume 4: Alternanthera philoxeroides, pp. 454 - text the same online as printed work, In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico, Volume 4 - Magnoliophyta: Caryophyllidae, part 1, Oxford University Press, New York and Oxford, 2003, ISBN 0-19-517389-9. ( Description section )