Picture of my twin two year old girls, Ayla (right) and Ellen (left), standing next to a self-sown Amaranthus cannabinus (tidalmarsh amaranth). This plant is about 18 feet tall and amazingly over 13 feet across. I can't get over how wide this plant is growing. This plant may have crossed with an Amaranthus australis (giant amaranth). I grew the tidalmarsh amaranth in that location the previous year, but they were overshadowed by the giant amaranth; so they didn't do much. However, they did flower at the same time; so they may have crossed. The tidalmarsh amaranth is very similar to the giant amaranth, but the leaves are thinner, as well as the stalk and branches. The base of this plant, last I looked several weeks ago, was about 15 inches in circumference