polygonum Known as rau ram in Vietnam, pak chi wietnam in Thailand, Vietnamese coriander in North America, and Vietnamese mint in Australia, this delightful strong-tasting herb can be replaced by fresh basil or mint, but the tastes are not the same. It can often be found fresh in Southeast Asian grocery stores and can also be grown in summer gardens in North America and indoors through the winter; it is a perennial. The leaves are soft, smooth, and dark green (sometimes with a darker blotch), up to one inch long, and sharply pointed, on fleshy stems.