100-gram Dried River Leaf Creeper (Aganonerion polymorphum) River Leaf Vine, Vietnamese La Giang Herbal Tea | Sour Leaf Creeper, Sour-Soup Creeper La Lom. is a bushy shrub that grows to tall heights on trellis and poles. The foliage on this plant has a tart flavor, is a common ingredient in many Vietnamese recipes and traditional remedies. traditional Vietnamese soups (Canh Chua). Aganonerion polymorphum, also known as Aganonerion polymorphum, Aganonerion polymorphum, is a species of tree in the Apocynaceae family. Giang leaf is a wild-growing tree, vine family, vines 1.5-4m long, smooth, with white pus. Single-leafed, opposite-growing. The leaves have thin slabs, lanceolate oval-shaped, sharply pointed, heart-shaped or imprisoned base at the base, the upper side. Leaf giang is a species of vine plant, belonging to the oleander family, also known by other names such as conical leaves, rubber bands, cords. This plant is mainly distributed in China, Japan, Malaysia, Indonesia, Vietnam