M. flavescens may refer to:
Macrothemis flavescens, a carnivorous insect Magellania flavescens, a marine animal Malouetia flavescens, a flowering plant Maro flavescens, a sheet weaver Marsdenia flavescens, synonym of Leichhardtia flavescens, an eastern Australian vine Melese flavescens, an Argentinian moth Memecylon flavescens, a plant endemic to India Mesolestes flavescens, a ground beetle Mesoprion flavescens, a subtropical fish Metareva flavescens, an Argentinian moth Microbacterium flavescens, a Gram-positive bacterium Miltonia flavescens, a South American orchid Mitra flavescens, a sea snail Monema flavescens, an Asian moth Monocerotesa flavescens, a geometer moth Mycena flavescens, a fungus with an edible mushroom Mycobacterium flavescens, a Gram-positive bacterium Mytilaspis flavescens, a scale insect