In Eurasia, this species of dodder would often attach itself to the Conehead thyme (Thymus capitatus), taking on the plant's pungency.

It has thin (0.25–0.40 mm) hairless filiform (thread-like) stems that are pink, red, yellow or purple.

[3] As a native species C.epithymum occurs from Macaronesia in the west throughout most of Europe to as far east as Xinjiang in Northwest China.

[3] C.epithymum has been unintentionally introduced into North and South America, Southern Africa, Australia, New Zealand and Primorsky Krai (southeastern Russia).

The commonest (>20% affected) host plants are Achillea millefolium (Yarrow), Galium verum (Lady's bedstraw), Arrhenatherum elatius (False oat grass), Plantago lanceolata (Ribwort plantain), Lotus corniculatus (Bird's foot trefoil), Sanguisorba minor (Salad burnet), Festuca rupicola (Furrowed fescue), Teucrium chamaedrys (Wall germander), Daucus carota (Wild carrot) and Convolvulus arvensis (Field bindweed).

The seeds have evidence of both physiological and physical dormancy, allowing them to survive in the soil for several years.

It then tightens and sends out haustoria that penetrate through the epidermis into the underlying xylem, allowing the parasite to draw both water and nutrients from the host.

On some perennial hosts it forms small galls, where parasitic tissue can survive the winter, from which new shoots can grow the following spring.

[12] Due to the wide range of hosts, its ability of its seeds to lie dormant for long periods and the damage caused to the host plants, C.epithymum is of major economic concern in agriculture, both within its native range and in many places where it has been introduced.