What is "rhizanthes"

Rhizanthes is a genus of 4 species of parasitic flowering plants without leaves, stems, roots, or photosynthetic tissue. They grow on roots of a few species of Tetrastigma vines. The genus is limited to the tropical forests of south and south-east Asia. The flowers of Rhizanthes vary from 14 to 43 cm in diameter. At least one species of Rhizanthes, R. lowii, is endothermic. It not only produces its own heat, but has the rare ability to regulate its own temperature.