buttonweed noun8 •Any of numerous species of plants with button-like flowers. •Any of several plants of the genera Diodia and Hexasepalum (syn. Diodella), of the madder family. •False buttonweed (Spermacoce spp.). •Velvetleaf, Indian mallow (Abutilon theophrasti). •Certain knapweeds (Centaurea spp.). •Clustered bluet (Oldenlandia uniflora). •Dwarf mallow, common mallow (Malva neglecta). •Water buttons (Cotula spp.). formsbuttonweeds
