Polygonaceae: Knotweed Family — Rumex (Dock)
Flowers in this family do not have separate petals and sepals. For plants like this, the term “perianth” is used to describe the flower (i.e. the calyx and the corolla together) and “perianth parts” to describe the individual elements, whether or not they are distinguishable. Docks are identified not by their inconspicuous flowers but by their leaves, their growth habit, and by what used to be described as “valves” but are now called “perianth lobes”. There are 6 perianth lobes, the outer 3 very small, the inner 3 larger and clearly visible. Callosities (small white lumps) may be present on one or more of these inner perianth lobes; their number and size are important diagnostic features. In some cases, it is impossible for the non-expert to identify species, without seeing the mature perianth and its callosities.