A: I am glad you brought me a photo of this plant. The grasses and grass-like plants are very difficult to identify but this one is fairly easy since you showed me a seed head and it was about 12 feet tall. I believe is it Giant reed, Arundo donax, which is a very large plant often found growing as a dense stand in water, topped by very large, feathery, plume-like inflorescences or seed heads. Giant reed is a source of reeds for musical instruments and industrial cellulose. Giant reed is a non-native large grass and is classified as a noxious weed in 46 states, according to the USDA. The rhizomes are hard and thick; the stems are cane-like, tall, erect or leaning reaching heights up to 20 ft. tall. The cane-like stems are what made you think it was bamboo. Controlling this plant is going to be difficult because of the rhizomes. Applying a concentration of glyphosate (Round-up) on cut stems will be necessary to control it. It will most likely take more than one application to work. Removing the seed heads will also be beneficial. When removing the seed heads, be sure to bag them immediately and throw them away.