Persicaria odorata (Lour.) Soják - syn.Polygonum odoratum Lour. - Polygonaceae
Vietnamese coriander, Vietnamesischer Koriander
Perennial herb, up to 30cm high, native from Vietnam to Malyasia; stems red; leaves dark green with brown markings; flowers inconspicuous, white to pale yellow.
„Above all, the leaf is identified with Vietnamese cuisine, where it is commonly eaten fresh in salads (including chicken salad) and in raw summer rolls (gỏi cuốn), as well as in some soups such as canh chua and bún thang, and stews, such as fish kho tộ.“
„The herb has a coriander-like smell with a clear lemony note. Pungency, which dominates in the closely related water pepper, is hardly present.“ http://gernot-katzers-spice-pages.com/engl/Pers_odo.html
The steam-distilled essential oil (0.52% yield) from the leaves and stems of Polygonum odoratum Lour. contained dodecanal (44.0%), decanal (27.7%), and decanol (10.8%) as main constituents.
[Composition of Polygonum odoratum Lour. from southern Australia., Hunter, M.V., Brophy, J.J., Ralph, B.J., Bienvenu, F.E., Journal of Essential Oil Research, 9(5), 1997, 603-604]
„Polygonum odoratum Lour. has been reclassified as Persicaria odorata (Lour.) Soják [Wilson, K. L. Polygonum sensu lato (Polygonaceae) in Australia. Telopea 1988, 3, 177−182]; other synonyms currently used are Vietnamese mint or Vietnamese coriander and, in Malaysia, Daun Laksa or Laksa plant. The aerial parts of Laksa plant are highly aromatic, and they contain many organic compounds such as (Z)-3-hexenal, (Z)-3-hexenol, decanal, undecanal, and dodecanal that are typical for green, citrus, orange peel, and coriander odors. In addition to these aldehydes, 3-sulfanyl-hexanal and 3-sulfanyl-hexan-1-ol were discovered for the first time in this herb. The fresh leaves are pungent when they are chewed, although the active compound has never been identified. The pungency of Persicaria hydropiper (L.) Spach (formerly Polygonum hydropiper L., synonym water pepper) is produced by polygodial, a 1,4-dialdehyde derived from drimane terpenoids. We also identified polygodial as the active pungent compound in P. odorata (Lour.) Soják.“
[Comparison of volatile constituents of Persicaria odorata (Lour.) Sojak (Polygonum odoratum Lour.) and Persicaria hydropiper L. Spach (Polygonum hydropiper L.)., Starkenmann, C., Luca, L., Niclass, Y., Praz, E., Roguet, D., Journal of agricultural and food chemistry, Vol.54(8), 2006, 3067-3071]