tumbleweed

(noun) any plant that breaks away from its roots in autumn and is driven by the wind as a light rolling mass.

(noun) prickly bushy Eurasian plant; a troublesome weed in central and western United States. Synonyms: Russian thistle, Russian tumbleweed, Russian cactus, Salsola kali tenuifolia.

(noun) bushy annual weed of central North America having greenish flowers and winged seeds. Synonyms: winged pigweed, Cycloloma atriplicifolium.

(noun) bushy plant of western United States. Synonyms: Amaranthus albus, Amaranthus graecizans.