Noun tarweed has 2 senses
- tarweed - any of various resinous glandular plants of the genus Madia; of western North and South America
--1 is a kind of herb, herbaceous plant
--1 is a member of Madia, genus Madia
--1 has particulars: melosa, Chile tarweed, madia oil plant, Madia sativa
- gumweed, gum plant, tarweed, rosinweed - any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock
--2 is a kind of herb, herbaceous plant
--2 is a member of Grindelia, genus Grindelia
--2 has particulars: Grindelia robusta; curlycup gumweed, Grindelia squarrosa
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