Menyanthes trifoliata Menyanthes trifoliata seeds with a mm ruler on top. Menyanthes trifoliata with immature fruits. Menyanthes trifoliata seedlings with seed leaves (left; cotyledons) and true leaves (right). Menyanthes trifoliata growing in a 4-inch container at the Berry Seed Bank research nursery located in Portland, Oregon. Menyanthes trifoliata in an aquatic environment for sale at a nursery near Snohomish, WA. Menyanthes trifoliata in a wetland near Laevenworth, WA. Menyanthes trifoliata flowering in a bog at Fish Lake, WA. Menyanthes trifoliata flower.