Dodder is an annual plant that reproduces from seed and stem pieces. To survive, seedlings must attach to a suitable host soon after emergence. This relationship is parasitic, not symbiotic. Seedlings grow upright for 2 to 4 inches before attaching to host. Plants are yellow due to a limited amount of chlorophyll.
Stems appear as leafless, thread-like branching vines.
Older plants produce a mat of stems over the host and entwine and attach to the host with sucker-like organs called haustoria. Roots are non-existent or very reduced. Roots support the seedling until attached to the host. The root system is not suitable for nutrient uptake, but can absorb water. However, dodder is succulent and seldom needs water as a seedling.