Pelargonium 'citrosum' (often sold by the invalid binomial name Pelargonium citrosum) is a perennial subshrub with fragrant leaves that are reminiscent of citronella. Pelargonium 'citrosum' is marketed as "mosquito plant" or "citrosa geranium" in stores in the United States and Canada, even though research indicates the plant is ineffective against Aedes aegypti mosquitos. "Not only was the plant ineffective at protecting humans against Aedes mosquito bites, the mosquitoes were seen landing and resting on the citrosa plant on a regular basis."