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From: Plano, TX
Region: Southwest
Topic: Propagation
Title: Prosopsis velutina (velvet mesquite), Larrea tridentata (creosote bush), rain smell
Answered by: Nan Hampton
In addition to the volatile oils from plants, a big contributor to the distinctive smell that comes after rain is soil bacteria. You should certainly still be able to experience this smell in Plano.
Mr. Smarty Plants has been assuming that you are talking about the distinctive smell that follows a rain, but people also report a unique smell that comes right before a rain. The smell BEFORE the rain has been attributed to a chemical called Petrichor, or in chemical terms—2-decanone. The chemicals that are constantly being volatilized and released from trees and other plants can be absorbed by rocks. The increase in humidity right before a rain has the effect of releasing these chemicals from the rock and creating the smell. Velvet mesquite and/or creosote bush must have this chemical in their makeup if they are contributing to the before-rain smell.
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