Lathraea squamaria

Lathraea squamaria, the common toothwort, is a species of flowering plant in the family Orobanchaceae. It is widely distributed in Europe and also occurs in Turkey. It is parasitic on the roots of hazel and alder, and occasionally other trees, and represents the second occasion on which a member of the family Orobanchaceae lost the ability to photosynthesize and became parasitic. It occurs in shady places such as deciduous woodland and hedge sides. The plant consists of a branched whitish underground stem closely covered with thick, fleshy, colourless leaves, which are bent over so as to hide under the surface. The only portions that appear above ground in April to May are the short flower-bearing shoots, which bear a spike of two-lipped dull purple flowers, but is also able to produce cleistogamic underground flowers which fertilise themselves. It is also able to regenerate from broken fragments of the underground stem....read more on Wikipedia.