Hi. This weed gets white flowers off the stem right where the leaves come out. The flower cluster forms a little marble or smaller sized ball. It gets about a foot tall where I've let it grow because my Queen Butterfly nectared from it. There are large photos of it on this page: http://butterflies.heuristron.net/plants/whiteball.html I'd really like to know what it's called, but it's hard to look up plants without at least a common name, and I have no idea what this one is. Thanks!