Water-pepper
Encyclopedia
Water-pepper or Water pepper (Persicaria hydropiper, syn. Polygonum hydropiper) is a plant of the family Polygonaceae
. It grows in damp places and shallow water. It is a cosmopolitan plant, found in Australia, New Zealand, temperate Asia, Europe, and North America. It has some use as a spice because of its pungent flavour.
s. Two bicyclic sesquiterpenoids are present, polygodial
(tadeonal, an unsaturated
dialdehyde
with a drimane backbone) and waburganal, which has been found responsible for the pungent taste (hence its edibility). The plant also contains rutin
, a source of the bitter taste impression.
The plant contains an essential oil
(0.5%) which consists of monoterpenoids and sesquiterpenoids: α-pinene
, β-pinene
, 1,4-cineol, fenchone
, α-humulene, β-caryophyllene, trans-β-bergamotene. Carboxylic acid
s (cinnamic
, valeric
and caproic acid) and their ester
s were present in traces. The composition depends strongly on genetic factors.
this plant's leaves
are used as a vegetable
- these are from the cultivar
, not the wild type
which has a far more pungent taste. Wild waterpepper produces oils that cause skin irritation, and the many acids in its tissues, including formic acid
, make the plant unpalatable to livestock.
The seeds of the water-pepper may be added to wasabi
.
Polygonaceae
Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...
. It grows in damp places and shallow water. It is a cosmopolitan plant, found in Australia, New Zealand, temperate Asia, Europe, and North America. It has some use as a spice because of its pungent flavour.
Active ingredients
The water-pepper has several active ingredientActive ingredient
An active ingredient is the substance of a pharmaceutical drug or a pharmaceutical ingredient and bulk active in medicine; in pesticide formulations active substance may be used. Some medications and pesticide products may contain more than one active ingredient...
s. Two bicyclic sesquiterpenoids are present, polygodial
Polygodial
Polygodial is an active constituent of Dorrigo Pepper, Mountain Pepper, Horopito, Canelo, Paracress and Water-pepper.Chemically it is a drimane-type sesquiterpene dialdehyde of formula C15H22O2.It elicits a warm and pungent flavour....
(tadeonal, an unsaturated
Saturation (chemistry)
In chemistry, saturation has six different meanings, all based on reaching a maximum capacity...
dialdehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
with a drimane backbone) and waburganal, which has been found responsible for the pungent taste (hence its edibility). The plant also contains rutin
Rutin
Rutin, also called rutoside, quercetin-3-O-rutinoside and sophorin, is a citrus flavonoid glycoside found in buckwheat, the leaves and petioles of Rheum species, and asparagus...
, a source of the bitter taste impression.
The plant contains an essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
(0.5%) which consists of monoterpenoids and sesquiterpenoids: α-pinene
Alpha-Pinene
α-Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. It is also found in the essential oil of rosemary...
, β-pinene
Beta-Pinene
beta-Pinene is a colorless liquid, soluble in alcohol, but not water. It has a woody-green pine-like smell. It occurs naturally in rosemary, parsley, dill, basil, yarrow, and rose. It is also a major constituent of hop aroma and flavor....
, 1,4-cineol, fenchone
Fenchone
Fenchone is a natural organic compound classified as a monoterpene and a ketone. It is a colorless oily liquid. It has a structure and an odor similar to camphor.Fenchone is a constituent of absinthe and the essential oil of fennel....
, α-humulene, β-caryophyllene, trans-β-bergamotene. Carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
s (cinnamic
Cinnamic acid
Cinnamic acid is a white crystalline organic acid, which is slightly soluble in water.It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter and is the best indication of its environmental history and post-extraction conditions...
, valeric
Valeric acid
Valeric acid, or pentanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula C5H10O2. Like other low-molecular-weight carboxylic acids, it has a very unpleasant odor. It is found naturally in the perennial flowering plant valerian , from which it gets its name. Its...
and caproic acid) and their ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s were present in traces. The composition depends strongly on genetic factors.
Edibility
In JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
this plant's leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are used as a vegetable
Vegetable
The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....
- these are from the cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
, not the wild type
Wild type
Wild type refers to the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard, "normal" allele at a locus, in contrast to that produced by a non-standard, "mutant" allele...
which has a far more pungent taste. Wild waterpepper produces oils that cause skin irritation, and the many acids in its tissues, including formic acid
Formic acid
Formic acid is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant, formica, referring to its early...
, make the plant unpalatable to livestock.
The seeds of the water-pepper may be added to wasabi
Wasabi
, also known as Japanese horseradish, is a member of the Brassicaceae family, which includes cabbages, horseradish, and mustard. Its root is used as a condiment and has an extremely strong flavor. Its hotness is more akin to that of a hot mustard rather than the capsaicin in a chili pepper,...
.
External links
- Jepson Manual Treatment
- Australian Plant Name Index (APNI), Australian National Botanic Gardens, Australian National Herbarium: Persicaria hydropiper (L.) Delarbre http://www.anbg.gov.au/cgi-bin/apni?taxon_id=287693