Noun mustard tree has 2 senses
- tree tobacco, mustard tree, Nicotiana glauca - evergreen South American shrub naturalized in United States; occasionally responsible for poisoning livestock
--1 is a kind of tobacco
- toothbrush tree, mustard tree, Salvadora persica - glabrous or pubescent evergreen shrub or tree of the genus Salvadora; twigs are fibrous and in some parts of the world are bound together in clusters and used as a toothbrush; shoots are used as camel fodder; plant ash provides salt
--2 is a kind of fruit tree
--2 is a member of Salvadora, genus Salvadora
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