This weed is driving me nuts. Don't have a picture but I think I can describe it fully. The leaves are arrowhead shaped, chartruese in color with a darker brown arrowhead patch in the center. As it gets older the leaves turn darker and in the late summer they send up a tall shoot with little white seeds all along the shoot. They get about 24" tall. Right now the plants are small, I pulled one of them and they have a dark brown bulb on the end and have more little leaf shoots coming from it. Once it gets older it's hard to pull. I thought I got them all cut down last fall by apparently I missed some shoots as now I have little tiny green plants growing in my garden bed. Does anyone know what these things are?