Family: Polygonaceae
Scientific Name: Rumex crispus 
Common Name: Curly Dock, Yellow Dock, Sour Dock
Description:
An alien plant that has spread throughout most of the USA. A common weed of pastures and fields.
plant type:
Weeds
Hardiness zone:
Sunlight:
full
Moisture:
average to wet
Soil & Site:
average to wet
Media:
Temperature:
Flowers:
The green flowers are on a loose inflorescence drying to a brown inflorescence of seeds. The fruit is a 3-valved or 3-winged triangular brown achene.
Foliage:
The stems are jointed having a sheath at the base of the leaf. The name is derived from the crisped or wavy margins of the leaves. The leaves develop a purple ting with age.
Dimensions:
I have seen it at least 3 feet tall reported to reach 5'.
Maintenance:
Propagation:
spreads by seeds
Origin & History:
Eurasia
Notes & Reference:
Growing up we called this plant "Indian Tobacco". Which is probably wrong, since I can’t find any reference to this common name in books? Chippewa Indians found some medicinal use for this plant. (References: #19-Common Weeds, #12-How Indians Used Wild Plants for Food, Medicine and Crafts)
Photos: