Hour flower
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Hour flower |
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The hour flower ( Hibiscus trionum ), also known as the hour rose , annual or hour rose , is a type of plant from the genus Hibiscus ( Hibiscus ) within the mallow family (Malvaceae). It is widespread in the Old World and is a neophyte in many areas of the world .
description
Appearance and leaf
The hour flower grows as an annual, rarely as a biennial herbaceous plant and usually reaches heights of about 20 to 50 cm, sometimes up to 80 centimeters. The stem is somewhat bristly haired. The alternate leaves are arranged in a petiole and a leaf blade. The petiole is 2 to 4 inches long. The 3 to 6 cm large leaf blade has two different shapes: simply ovoid or three to five lobed. The thread-like stipules are about 7 mm long.
Flower, fruit and seeds
Each flower only opens for one day during the main flowering period from June to September and then only for a few hours (hence the name). The flowers are solitary in the leaf axils. The flower stalk is about 2.5 cm long and extends to about 4 cm when the fruit is ripe. The hermaphroditic flowers are up to 8 centimeters in diameter, radial symmetry and five-fold. The secondary calyx consists of twelve thread-like lobes about 8 mm in size that are only fused at their base. Particularly noticeable is the inflated calyx, which consists of five greenish, 1.5 to 2 cm long sepals that are fused together over half their length . The five mostly white to pale yellowish petals have a dark purple-purple-black base ( juice mark ). In the subfamily Malvoideae , the stamens of the many stamens have grown together to form a tube surrounding the pistil , the so-called columna . The top 3 mm of the stamens are free. The anthers are yellow. There are five styluses.
The five-fold capsule fruit has a diameter of about 1 cm. The seeds are black.
Chromosome number
The number of chromosomes is 2n = 28 or 56.
ecology
There is insect pollination and self-pollination .
It spreads mainly through self-sowing.
Occurrence
Hibiscus trionum is widespread from the eastern Mediterranean to southern Africa and Madagascar and from western Asia to central Asia and Pakistan to China and Australia. It is a neophyte almost worldwide in warm, climate-favored areas . It is, for example, naturalized in the entire Mediterranean region up to the foot of the Alps or. It is very rare in western Central Europe and inconsistently overgrown in climate-favored areas. As the only hibiscus species in Europe, more precisely in southeastern Europe , the hour flower occurs only inconsistently in Germany . In the southeastern European distribution area it is an eragrostion association character.
In Austria the hibiscus is at home in Vienna , Lower Austria , Burgenland and Styria . In Upper Austria , Carinthia , Salzburg and Vorarlberg it occurs only inconsistently. The earlier inconsistent occurrences in Tyrol have died out. The species occurs seldom in Austria and especially in the Pannonian flora province in the colline altitude range in warm, dry to moderately moist ruderal fields, root crop fields, vineyards and ruderally influenced lawns. The hibiscus is considered endangered in Austria.
The sun- loving hour flower is frost hardy and, in Central Europe, is widespread as an inconsistent " weed " on root crop fields, on fallow land and along roadsides. The hour flower thrives best on loose, stony or gritty-sandy loam soils , which should contain a little nitrogen and can be quite dry at times.
Taxonomy
Hibiscus trionum was first published in 1753 by Carl von Linné in Species Plantarum , 2, p. 697. Synonyms for Hibiscus trionum L. are: Hibiscus africanus Mill. , Hibiscus trionum var. Cordifolius DC. , Hibiscus vesicarius Cav. , Ketmia trionum (L.) Scop. , Trionum annuum med. , Trionum trionum (L.) Wooton & Standl. The specific epithet trionum means "the northernmost" and refers to the fact that it is the most northern species of the mainly tropical genus Hibiscus .
use
It is used as an ornamental plant.
literature
- Ya Tang, Michael G. Gilbert, Laurence J. Dorr: Malvaceae. : Hibiscus trionum , p. 264 - the same text online as the printed work , In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Ed.): Flora of China. Volume 12: Hippocastanaceae through Theaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2007. ISBN 978-1-930723-64-1
Individual evidence
- ↑ a b Hour rose marshmallow. In: FloraWeb.de.
- ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 657.
- ↑ a b c Dietmar Aichele, Heinz-Werner Schwegler: The flowering plants of Central Europe. Volume 3: Evening primrose plants to reddish plants. Franckh-Kosmos, Stuttgart 1995, ISBN 3-440-06193-0 .
- ^ Manfred A. Fischer, Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol . 3rd, improved edition. Province of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 618 .
Web links
- Hour flower. In: FloraWeb.de.
- Distribution map for Germany. In: Floraweb .
- Hibiscus trionum L. In: Info Flora , the national data and information center for Swiss flora . Retrieved December 8, 2015.
- Thomas Meyer: Data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )
- Data sheet with photos.
- Data sheet with photos.