H. flavescens may refer to:
Haliclona flavescens, a marine demosponge Halisidota flavescens, a North American moth Haloa flavescens, a bubble snail Halone flavescens, an Indian moth Haminoea flavescens, a bubble snail Harpalus flavescens, a ground beetle Hedychium flavescens, a perennial ginger Helcystogramma flavescens, a Russian moth Heleophis flavescens, a water snake Heliothis flavescens, an African moth Hesperilla flavescens, an Australian butterfly Heteroclinus flavescens, a Pacific clinid Heteronygmia flavescens, a tussock moth Hibana flavescens, an anyphaenid sac spiders Homoranthus flavescens, a myrtle endemic to New South Wales Hoplopheromerus flavescens, a robber fly Hygrocybe flavescens, a waxy cap Hygrophorus flavescens, a waxy cap Hyllus flavescens, a jumping spider Hylorana flavescens, a true frog Hymenopappus flavescens, a North American plant Hypocnemis flavescens, a South American antbird Hypoestes flavescens, a flowering plant Hypomyces flavescens, a parasitic fungus