Kusamono (literally "grass thing") and shitakusa (literally "undergrass") are a potted collection of plants designed to either be viewed in accompaniment with bonsai, or alone.

Normally the term kusamono is used when the planting is displayed as the center of attention, while the term shitakusa is used for plantings that accompany bonsai displays. Kusamono and shitakusa are displayed separately in special pots, driftwood, or even stones.

While traditionally in Japan, plants gathered from mountains contributed to the bulk of companion plantings, modern use has extended to more creative and artistic design.