Persicaria hydropiper
Smartweed ( Persicaria hydropiper ) - Illustration of 1832
Smartweed ( Persicaria hydropiper, Syn: Polygonum hydropiper ), also flea pepper, Pfefferknöterich, pepper herb or herb called Sharp, a plant is of the genus Knöteriche ( Persicaria ). The pungent-tasting leaves and seeds are sometimes used as a spice.
- 4.1 Etymology
- 5.1 Internal systematics
Description
Habit and roots
The water pepper is an annual herbaceous plant, a Therophyt. It germinates from April to May and dies of drought or at the latest at the first frost. The stem is erect, ascending or horizontal and green, often with a red ring after each node. Branches grow out from the basal leaf axils. During aging ( senescence ), the whole stalk discolored from bottom to top reddish. He is bald or slightly hairy. The plant reaches on a good location stature heights between 75 and 90 centimeters, austere locations it remains small between ten and 15 centimeters.
The root system is heterogeneous and consists of a maximum of about ten inches long, growing vertically downwards, often twisted shape taproot and lateral off of their lateral roots. If the lower part of the plant covered with substrate, grow from the nodes of adventitious roots. Mycorrhizae are not known.
The set of chromosomes water pepper twice with 2n = 20 chromosomes.
The change-constant leaves are 3-12 inches long and 0.8 to 2 inches wide. They are brown on both sides dotted usually clustered near the midrib. Their shape is lanceolate, cuneate at the base, ciliate at the edge and with a sharp tip. The leaves are hairy on both sides glabrous or slightly glandular and not. The leaf stems have a length of 1 to 8 millimeters. The Ochrea (low leaf sheaths ) is usually hairy with very fine eyelashes and sometimes glandular. As with the stem, the leaves turn reddish during senescence. The stomata ( stomata ) are found almost exclusively on the underside of leaves.
Leaves and fruits contain the pungent polygodial, called Tadeonal. Chemically, it involves a drimane sesquiterpene dialdehyde with bicyclic structure. This substance acts as a corrosion inhibitor for insects.
In addition, leaves and fruits contain essential oils of α -pinene, β -pinene, 1,4- cineole, fenchone, α -phellandrene and α - humulene, β -caryophyllene, trans- α - bergamotene. In addition, trace amounts of carboxylic acids such as valeric acid and caproic acid, and esters thereof have been found.
Inflorescences, flowers and fruits
The flowering period extends from May to October but the main flowering period is from June to September. The terminal, often hanging, large, loose, eared inflorescence is 3-8 inches long. Smaller inflorescences arise from the axil of a small supporting sheet at each node, the lower nodes are very inconspicuous and cleistogamous ( self-pollinating in closed flowers ). These bracts are always shorter than the inflorescence axes. The Ochreolae (low leaf sheath of bracts ) is fringed, hairy hairless or slightly and glandular.
The flower stems are 0.5 to 1.25 mm long. The small hermaphrodite flowers have a diameter of 1.0 to 2.0 mm. The three, four or five green, at the top of some white or reddish bracts are densely covered with yellowish to brownish glands. The usual six or four, rarely five or eight stamens have pink to red dust bag. In each flower, two or three pens.
The flowers formula is:
It formed about 2.5 to 4 millimeters long and about 2 mm wide, dull, dark brown nut fruit, the ( domed on both sides ) a bikovexe or triangular ( trigonal ) shape with a grained, matte, finely warty, rough surface. Only the fruits of the cleistogamous flowers are completely irregularly shaped. All fruits are of matt black or dark brown color. The dry perianth remains attached to the fruit.
Ecology
The water pepper is about six months old and blooms from the age of six to ten weeks. The multiplication is done almost exclusively on generative seed, the species is thus a Amphimikt. Vegetative propagation does not take place in practice, even if separated parts of the stalk, if they contain at least one node, can grow again. Each plant produces in their lives between 300 and 400 seeds. These float on water, which certainly contributes to their proliferation, they also remain in the mud on the feet of animals stick and be carried away.
In sand, however, germinate approximately 3% of seed on clay 66%, 0% in peat. The seeds can germinate only if they previously were for some time, at temperatures between 2 and 4 ° C in water. The seed is not light sensitive and germinate in five to ten days. Germination is delayed above ground ( epigeal ). First breaks the nut at the tip and the root is displayed. Then the nut is lifted from the ground and falls in the expansion of the cotyledons ( cotyledons ) from. The cotyledons are at first red, discolor on exposure to light but fast to green.
The flowers pollinate themselves insect visits are rare, but occasionally visit aphids ( Aphidoidea ) the flowers and suck on the underside of leaves or on the flower stalk on phloem. The species is food plant of larvae of Phytobius waltoni, a species of weevils ( Curculionidae ).
The flowers are occasionally attacked by Sphacelotheca hydropiperis, a very specialized type of smut fungi ( Ustilaginomycetes ). The less specialized rust fungi ( Urediniomycetes ) Ustilago cordae and Microbotryum cordae and Rußtaupilz ( Capnodiales ) Septoria polygonorum infest the kind regularly.
Mammals do not eat the pepper water, they will probably put off by the peppery taste, the food value of the type is zero. The fruits are, however, readily accepted by the House Sparrow (Passer domesticus).
Dissemination and locations
Water pepper is distributed in temperate Eurasia and North America, they probably originated in Europe or Eurasia, and has already been introduced early in North America. In Europe, the distribution area includes the British Isles, and extends north to 65 ° north latitude. A few deposits are located but also further north and even beyond the Arctic Circle. To the east, the distribution area of Japan, the People's Republic of China and Korea includes. The southern boundary of the range in Southeast Asia passes through Malaysia, on the Indian subcontinent by Sri Lanka. Stocks also exist in the Philippines, New Zealand and in Queensland and South Australia. In North America, stocks found in the United States and Canada.
In the British Isles the water pepper altitudes reached to about 500 meters, in the People's Republic of China, the species is widespread but at altitudes of 3500 meters. Locations are never far from the water. Preference is given to areas that are flooded in winter. The type can be found everywhere but where it is moist enough, for example, wet clearings, in swamps, on river, lake and canal banks, or simply wet places. The plants are rarely alone, often in large clumps of several hundred individuals.
The substrate opposite to the species is very tolerant and settled both clayey and sandy soils. From Ireland was reported that calcareous soils are preferred. However, the soil must have a high early nitrate and calcium supply, the cation exchange capacity should be moderate and the pH will be six. The species colonized grazed areas and is very shatter-proof.
Phytosociological of water pepper is a characteristic species of the class Bidentetea ( tripartitae ) ( Two tooth - mud shore company).
Botanical history and etymology
The water pepper has been first described in 1753 by Carolus Linnaeus in the first volume of his Species Plantarum under the basionym Polygonum hydropiper. Linnaeus ordered the kind that is initially the kind of Vogelknöteriche ( Polygonum ) too. The first description was in reference to a number of type specimens ( syntypes ).
Already in 1800 ordered Antoine Delarbre the kind of the kind of Knöteriche ( Persicaria ) to. This assignment was taken over in 1841 by Édouard Spach and 1852 by Philipp Maximilian Opiz. In 1994, a type specimen ( lectotype ) was subsequently determined.
Etymology
The water pepper on the one hand on the pepper -like taste of the leaves and fruit and the other hand on the wet sites of Art The scientific epithet hydropiper goes directly to the classical Greek name ὑδροπέπερι hydropeperi back, with the water pepper is referred to in the Vienna Dioscorides. The name comes from ὕδωρ hydor (= water ) and πέπερι peperi ( = pepper) together.
System
Currently, there is no cladistic study of the phylogenetic relationships of the species of the genus Persicaria. But it is clear that the genus is not monophyletic, but compared to the genus Polygonum - needs to be more defined - and possibly also against Atraphaxis, Bistorta and Koenigia.
The next engine water pepper is very likely Persicaria foliosa. Natural hybrids are virtually excluded because of self-pollination, but has been reported with this type of hybrids.
Inside systematics
The species is very variable. The reddening of the leaves, however, can be traced back to the age of the plants and the strength of the light. So copies are with full sun location in August almost completely red. The differences in the number of floral organs does not constitute any further subdivision of the Art Still are four different forms:
- P. h f hydropiper: with lanceolate leaves
- P. hf obtusifolium A.Br.: with small blunt oval - lanceolate leaves
- P. hf angustifolium ( Duval ) A.Br.: with very narrow linear - lanceolate leaves
- P. hf densiflorum A.Br.: With short cylindrical, dense inflorescences
In addition to the natural forms in Japan, there are several varieties that have been produced by plant breeding. Particularly successful are the varieties Benitade and Aotade. The cultivated forms in some cases show that a high genetic variance compared to the wild forms.
Use
During excavations in the Lea Valley very old seeds were found but could not be clearly assigned to the water pepper. Sure is a use as a spice in the Bronze Age, this was confirmed by seed finds in many excavations.
Today, the water pepper is mainly as a weed of significance.
The pungent leaves were sometimes used in modern Europe as a pepper substitute, especially in times of need. Since the end of World War II, however, water pepper no longer plays a role in Europe.
In Japanese cuisine fresh water pepper leavesヤナギタデyanagi - tade regularly serve as decoration to salads or rice dishes.