Gnaphalium uliginosum
Marsh Cudweed ( Gnaphalium uliginosum ).
The bottom -Ruhr herb ( Gnaphalium uliginosum ) is a flowering plant in the sunflower family ( Asteraceae). It is distributed throughout the temperate and cool regions of the northern hemisphere.
- 4.1 Notes and references
- 4.2 Literature
Description
Appearance and leaf
In the swamp -Ruhr herb is an annual, herbaceous plant that reaches the plant height usually about 10 to 15 centimeters ( 3-25 inches ). However, often also occur unbranched Kümmerformen. One finds the plants almost exclusively in summer. The upright, usually from the bottom of protruding branches to spread stems are densely hairy to loose woolly.
The sessile, white to gray tomentose hairy leaves are usually at a length of 2-3 ( 1-5 ) cm and a width of 1 to 4 mm linear to oblong- spatulate or upside - lanceolate. The upper leaves are curled at the edges slightly.
Inflorescence, flower and fruit
The flowering period extends into central Europe from July to August. In terminal and lateral, more or less dense, knäueligen total inflorescences sit three to ten basket- shaped part inflorescences together. The flower heads are far overshadowed by forced standing together, foliage leaf -like bracts surround the. At a length of 5 to 15 millimeters and a width of 1 to 2 millimeters linear, inverted - lanceolate or obovate The flower heads are cylindrical with a height of 2 to 4 millimeters. The bracts are brownish woolly hairs in the area under and membranous; the inner are narrow - triangular, whitish, acute upper ends.
The flowers are whitish- yellowish. There are about three rows of available thread-like ray florets; they are only slightly longer than the florets. There are a few tubular flowers available.
The approximately 0.5 millimeters long, only 0.07 mg weight The bare or papillary and weakly hairy achenes are slightly compressed. The sparse, short, annular Pappus is 1.5 millimeters long.
Set of chromosomes
The basic chromosome number is x = 7; it lies in front of diploidy, ie a chromosome number of 2n = 14
Ecology
The Sunpf -Ruhr herb is a ( sommerannueller ) Therophyt, which reaches a root depth 7-25 cm.
Ecologically flowers are inconspicuous "basket flower "; the thread-like ray flowers are female. Pollinators are bees.
When wet exit from the achenes of sticky Viscinfäden that allow it to spread as Klebhafter and water Hafter. The seeds are long (over 50 years) capable of germination. Fruit ripening begins in August.
Occurrence
The bottom -Ruhr herb is widespread throughout the temperate and cool regions of the northern hemisphere. ( In Europe, from the Mediterranean to the Arctic Circle ). It is widespread in Central Europe. Whether the kind in North America was at home, or were introduced by humans, is not safe.
It originally grew mainly on open shelves at the waters edge. You can now find it much more common as a weed in fields, in gardens or along roadsides. Here, it often indicates a highly compacted soil on which waterlogging can form out, although it can grow with adequate soil moisture on loose soil.