Citronellal
Citronellal or rhodinal (C10H18O) is a monoterpenoid aldehyde, the main component in the mixture of terpenoid chemical compounds that give citronella oil its distinctive lemon scent. Citronellal is a main isolate in distilled oils from the plants Cymbopogon (excepting C. citratus, culinary lemongrass), lemon-scented gum, and lemon-scented teatree.