Cuscuta epithymum (L.) L.

In Great Britain and/or Ireland:
Foodplant / gall
Cuscuta epithymum causes gall of Ulex
Other: major host/prey

Foodplant / gall
Cuscuta epithymum causes gall of Calluna vulgaris

Foodplant / parasite
haustorium of Cuscuta epithymum parasitises stem of Eu-dicots

Foodplant / gall
larva of Smicronyx coecus causes gall of stem of Cuscuta epithymum

Foodplant / gall
larva of Smicronyx jungermanniae causes gall of stem of Cuscuta epithymum

Host: Convolvulus spinouts.

This species is close to Cuscuta europaea, from which it is differentiated by having purple stems, sessile stamens and sepal lobes with reticulate venation and style 2.5-3 mm long. Different forms of this species described by Yuncker are not recognized here both because only a limited number of collections are available, and the characters used by Yuncker for the separation of different forms intergrade.

Stem thin, purple, not interlaced, making a few spirals around the host stem. Leaves fleshy, oblong, acute-obtuse, slightly purple to brown, inflexed, c. 1 x c. 0.4 mm. Flowers in clusters of 4-5, sessile or subsessile, 22-25 mm. Bracts leaf-like. Calyx lobes 4, 1.8-2 x 1-1.5 mm, glossy, fleshy, elliptical to spathulate, with a prominent reticulate pattern, mostly obtuse or acute-obtuse, tips glandular, tube 1-12 mm long. Petals 1.8-2 x 1-12 mm, 4, broadly elliptical, membranous, with reticulate pattern, acute-obtuse or obtuse; tube c. 1 mm long; scales very thin, membranous, hard to see, fringed, c. 0.3 mm long. Stamens 4, sessile, free filaments obsolete, fused filaments prominent in the petals; anther oblong-elliptical, basifixed, light-brown, to dark-brown, c. 0.3 x c. 0.4 mm. Ovary globular, not depressed, fleshy, brown, with thick base, 2.5-3 x c. 0.4 mm, style linear, narrowing towards the apex, brown, 2.5-3 mm long; stigma linear, dark brown, c. 0.2 mm long; ovules 4, orbicular, light brown to yellow, c. 0.2 mm in diameter. Fruit not seen.

Distribution: Throughout the range of the genus.

Cuscuta epithymum (dodder, lesser dodder, hellweed, strangle-tare) is a parasitic plant assigned to the family Cuscutaceae or Convolvulaceae, depending on the taxonomy. It is red-pigmented, not being photosynthetically active. It has a filiform habit, like a group of yarns. Its leaves are very small, like flakes. Its flowers, disposed in little glomerules, have a white corolla, with the androecium welded to the corolla.

In Eurasia, this species of dodder would often attach itself to the Conehead thyme (Thymus capitatus), taking on the plant's pungency and from whence it also derived its host's Arabic name, al-ṣaʿitrah. During medieval times, dodder was often used as a medicinal cure in treating depression, but causes thirst and dryness of the mouth when consumed.