Not to be semantically confused with :
Toothed Medick [a plant with similar name belonging to a different Family]
Some similarities to : Common Broomrape and other Broomrapes which are also parasitic but those possess differently-shaped flowers.
Slight resemblance to : Yellow Bird's-Nest but that stoops all the way over like an umbrella handle and is yellowish.
It is in the same genus as: Purple Toothwort (Lathraea clandestina) but that is purple and is far shorter and lacks a central stem from which the flowers erupt.
The Toothworts lack chlorophyll so are completely unable to photosynthesize and must obtain their nutrients by parasitizing the roots of a host plant. The hosts of Toothwort itself are
Hazel and Alder, but is Saprophytic on
Beech tree roots.
Other species it is suspected of parasitizing (because it was found to be growing within 1m of - but it might not be because the plants were not uprooted to trace where any haustorial connections between the two actually went) are, in order of probability:
Poplar Trees, plus some plants which are not trees: Ivy, Lesser Celandine, Lords-and-Ladies, Wood Anemone, Ramsons, Bluebell, Dandelion and
Brambles. Other plants were also noted in the survey by John Faulkner but your Author here (i.e. me, Roger) has not included those of less frequent occurrences (but some may indeed also be hosts of Toothwort).
It occupies shady places like hedges. Toothwort might also be a borderline carnivorous plant, meaning that it can physically trap insects but only might be capable of digesting them and absorbing the nutrients, or partially absorbing them. Obviously, the more ways it has at its disposal for obtaining nutrients the better, and maybe carnivory is just supplementary until it can parasitize a nearby plant for a more reliable supply of nutrients. But it might not be protocarnivorous at all.