(Scaldweed). Dodder is a parasitic herbaceous vine with yellow to orange smooth stems. The flowers are 5-parted, white, about 1/8" long that appear in a dense cluster along the stem. The flowers are stalkless and the petals have rounded tips and appear to be wax-like. Leaves usually do not exist. There are a number of species of the genus, all parasitic. Seeds germinate on the ground and the slender thread-like stems begin to climb up adjoining plants. The stems then put out small vesicles that attach to the host plant. As soon as there are a sufficient number of attachments for Dodder to draw nourishment from the host plant, the root withers away and the parasite lives completely off the host. If a host is not found within a few days of germination the plant dies.

There are a large number of Dodder species, some restricted to quite local areas such as C. odontolepis, the Santa Rita Mountain dodder. Dodders are somewhat specific as to which host plants serve it best and some important scientific work has been done to support the claim that dodder is sensitive to certain plant odors, or pheromones, and that the plant responds to favorite odors. Entomologist Consuelo De Moraes at Pennsylvania State has shown the C. pentagona will move quickly to a tomato plant but avoid a wheat plant. Daniel Chamovitz, director of the Manna Center for Plant Biosciences at Tel Aviv University has published much on this including What a Plant Knows: A Field Guide to the Senses. Nevertheless, a single Dodder can attach itself to a number of plants in a given area, thereby causing great harm to specific plant communities. Previous botanical classifications put this plant in the Morning Glory family - the Convolvulaceae and some references such as the Comprehensively Annotated Checklist of the Flora of Minnesota still keep it there.