The stem of a plant entwined with dodder, Cuscuta americana. This is a parasitic non-green plant of the family Convolvulaceae. The seed of the dodder germinates sending a little root into the ground while the shoot elongates rapidly, growing in ever- widening circles. If it meets a suitable host plant it twines around the stem and produces suckers or haustoria which penetrate the tissues of the host. The xylem and phloem of these organs make contact with those of the host, and thus the parasite obtains organic substances as well as water and salts. Meanwhile the root of the dodder dies. Once established it produces leaves and flowers and grows vigorously.