Pelargonium 'citrosum' (often sold by the invalid binomial namePelargonium citrosum[1]) is a perennial subshrub with fragrant leaves that are reminiscent of citronella.[2]
Pelargonium 'citrosum'
P. 'citrosum' is marketed as "mosquito plant" or "citrosa geranium" in stores in the United States and Canada, even though research from the University of Guelph indicates the plant is ineffective against Aedes aegypti mosquitos.[3] "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."[1]
It is claimed that P. 'citrosum' may be a genetic bonding of the African geranium with genes from Cymbopogon grass, but that claim has also been proven false.[4] The plant appears to be a cultivar of Pelargonium graveolens.
The citronella geranium is not to be confused with others that are also called "mosquito plant", nor with the group of plants also known as citronella grass, or with Citronella mucronata (Chilean Citronella).
Pelargonium 'citrosum' is hardy to USDA Zone 10–11.[5]
^Matsuda, Brent M.; Surgeoner, Gordon A.; Heal, James D.; Tucker, Arthur O.; Maciarello, and Michael J., Essential oil analysis and field evaluation of the citrosa plant "Pelargonium citrosum" as a repellent against populations of Aedes mosquitoes. Department of Environmental Biology, University of Guelph, Guelph, ON, Can. Journal of the American Mosquito Control Association (1996), 12(1), 69-74. Publisher: American Mosquito Control Association, CODEN: JAMAET ISSN8756-971X. Journal written in English.
