As this is a parasitic species, all flower visits will be for nectar only.
Westrich (1989) lists the following as nectar sources: Taraxacum officinale, Cirsium, Carduus, Onopordum, Centaurea (Asteraceae) and Scabiosa (Dipsacaceae).
Celary (1989) lists the following nectar sources in Poland: Salix sp. (Salicaceae); Chamaenerion angustifolium (Onagraceae); Calluna vulgaris (Ericaceae); Lamium purpureum (Lamiaceae); Knautia arvensis (Dipsacaceae); Carlina vulgaris (Ericaceae); Carduus sp., Cirsium oleraceum, Centaurea scabiosa, Centaurea rhenana, Leontodon autumnalis, Taraxacum officinale (Asteraceae).
Pawlikowski & Kruszynski (1997) list Taraxacum officinale (Asteraceae); Scabiosa canescens (Dipsacaceae) and Thymus serpyllum (Lamiaceae) as nectar sources in Poland.
In Spain, Ornosa & Ortiz-Sánchez (2004) list the following plant families as providing nectar: Asteraceae and Lamiaceae.