Polygonum

but modified
1Perennial plant with woody rootstock, sometimes even like a subshrub
1'Annual plant
2Inflorescences leafy, the flowers in small axillary clusters; leaves coriaceous
2'Inflorescences spiciform, terminal, slender, not leafy; leaves not coriaceous
3Inflorescences leafy; flowers solitary, axillary, or in small axillary clusters; bracts leaf-like, longer than the flowers
3'Inflorescences not leafy, spiciform; at least the upper bracts inconspicuous and shorter than the flowers
4Perianth pink and white
4'Perianth green, sometimes with pink or white margins