They are called parasitic plants because they feed off of tree-nourished soil fungi. One of them is called Candystick, Allotropa. Peter Baye recently found one growing in his forest, the first he has seen in 15 years.
These plants are only found in mature, old forest soils. Any disturbance of the soil is a threat to these flowers. Keep part of your land wild for the sake of native plants and wildlife!
Thanks to Peter for allowing me to share his photos with you here.