Speedtree trees each have a little white ball that is undeletable (!)

hi, using the free speedtrees, conifer and broadleaf.
how do i get rid of the little white balls from the speedtrees?
i put the speedtrees in last autumn and each tree generated a little white sphere, like a white balloon or cancerous grown on its trunk, growing on the trunk of each tree. so when i delete the trees, the little white sphere stays and even shows up onscreen during gameplay, the white balls won’t go away! i updated to the newer version of free speedtrees and this problem still persists with both old and new versions. how do i get rid of the little white balls from the speedtrees?
i am using unty 5.4. 0.f1 with an nvidia card. system seems fine, is this a speedtree issue maybe???

thanks!

-benb