Persicaria odorata Persicaria odorata Persicaria odorata, known as rau răm or Vietnamese coriander, is an herb whose leaves are used in Southeast Asian cooking. Other names for this herb include Vietnamese mint, Vietnamese cilantro, Cambodian mint, hot mint, laksa leaf, and praew leaf. Vietnamese coriander is not related to the mints, nor is it in the mint family Lamiaceae, but its general appearance and fragrance are reminiscent of them. "Persicaria" is in the family Polygonaceae, collectively known as "smartweeds" or "pinkweeds". Above all, the leaf is identified with Vietnamese cuisine, where it is commonly eaten fresh in salads (including chicken salad) and
Leaf power powers for bounded values of have bounded clique-width, but this is not true of leaf powers with unbounded exponents. A graph is a 2-leaf power if and only if it is the disjoint union of cliques (i.e., a cluster graph). A graph is a 3-leaf power if and only if it is a (bull,dart,gem)-free chordal graph. Based on this characterization and similar ones, 3-leaf powers can be recognized in linear time. Characterizations of 4-leaf powers are given by and , which also enable linear time recognition. For "k" ≥ 5 the recognition problem of "k"-leaf powers is open, and likewise