Small's jointweed, Polygonella myriophylla

Maybe this should be a between-the-joint weed? Most plants in the buckwheat family have branches only at stem joints surrounded by a sheath. Polygonella also has branches between the nodes. There are numerous species in the South, and watching for that feature is a good start for identification. Small's only grows in a very limited area in central Florida, where it is endangered by development and agriculture. Next time you enjoy an orange, give thanks to Small's jointweed for giving up its habitat? Polk Co FL, 10/21/15. Buckwheat family, Polygonaceae.