Conifer

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Conifer
Crassula helmsii.jpg

Coniferous herb ( Crassula helmsii )

Systematics
Nuclear eudicotyledons
Order : Saxifragales (Saxifragales)
Family : Thick-leaf family (Crassulaceae)
Subfamily : Crassuloideae
Genre : Thick leaf ( Crassula )
Type : Conifer
Scientific name
Crassula helmsii
( Kirk ) Cockayne

The coniferous herb ( Crassula helmsii ) is a species of plant from the genus thick leaf ( Crassula ) in the family of thick leaf plants (Crassulaceae).

description

The conifer is an annual to weakly persistent , strongly branched plant whose shoots crawl with erect ends and reach heights of up to 12 centimeters. Floating shoots grow up to 25 centimeters long. The rather flat and slightly fleshy, green to brown leaves are oblong lanceolate to oblong elliptical. They are 3 to 8 millimeters (rarely up to 12 millimeters) long and 1 to 2 millimeters (rarely 0.8 to 8 millimeters) wide.

The four-fold flowers appear individually in the leaf axils . Your flower stalk is 4 to 7 millimeters long at the time of fruiting. The triangular sepals are 0.6 to 0.8 millimeters (rarely up to 1 millimeter) long. The cup-like corolla is white. Your lanceolate, pointed petals are spread out to slightly bent back and have a length of 1.6 to 2 millimeters. The oblong, wedge-shaped, clipped nectar flakes are white.

The seeds are smooth or have fine, often incomplete longitudinal ribs.

Occurrence

The coniferous herb also called Australian needle herb is common in New Zealand , in the southeast of Australia including Tasmania . In Western Europe (including England and Scotland ) it has been introduced and feral as a weed in many places. In the United Kingdom, the sale of the plant (known there as the Australian swamp stonecrop ) was therefore banned with effect from April 2014.

The species has been recorded in Germany since 1981, where it was first found in the Palatinate Forest and later in Lower Saxony, Bremen, Hamburg and Hesse. Since it can displace native freshwater organisms, it was placed on the black list of invasive species (early warning list) in Germany in 2013 . In Switzerland it was added to the black list of invasive neophytes and made subject to the release ordinance.

She is naturalized in societies of the Potamogetonion pectinati or the Littorellion.

Systematics

The first description as Tillaea helmsii by Thomas Kirk was published in 1899. Leonard C. Cockayne placed the species in the genus Crassula .

proof

literature

Individual evidence

  1. ↑ Rolf Wisskirchen, Henning Haeupler: Standard list of fern and flowering plants in Germany. With chromosome atlas . Ed .: Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 1 ). Eugen Ulmer, Stuttgart (Hohenheim) 1998, ISBN 3-8001-3360-1 , p. 157 .
  2. ^ Mark Kinver: UK bans sale of five invasive non-native aquatic plants. BBC News, January 29, 2013, accessed January 29, 2013 .
  3. ↑ Gießen regional council, https://rp-giessen.hessen.de/pressemitteilungen/amphibienteiche-im-naturschutzgebiet-hu%C3%9Fgeweid-im-am%C3%B6neburger-becken-von
  4. ↑ Birgit Seitz, Stefan Nehring, Andreas Hussner: Nature Conservation Invasiveness Assessment Crassula helmsii - needle herb ; created June 30, 2013. - Federal Agency for Nature Conservation, Bonn: 2 pp.
  5. ^ Federal Office for the Environment FOEN: Invasive Alien Species . ( admin.ch [accessed on August 6, 2019]).
  6. ↑ S. Buholzer, M. Nobis, N. Schoenenberger, S. Rometsch: List of the alien invasive plants of Switzerland . Ed .: Infoflora. ( infoflora.ch [accessed on August 6, 2019]).
  7. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 480.
  8. ↑ Thomas Kirk: The Student's Flora of New Zealand . 1899, p. 142 ( online ).
  9. ^ Transactions and Proceedings of the New Zealand Institute . Volume 39, 1907, p. 349 ( online ).

Web links

Commons : Needlewort ( Crassula helmsii )  - Collection of pictures, videos and audio files