Period of warmer climate that separates two glacial periods. Mid-latitude interglacials show a characteristic sequence of vegetation change. Pollen of heathy tundra is replaced in the pollen record by abundant herbaceous pollen, which in turn is replaced by that of boreal and subsequently deciduous forest, including pollen of thermophilous (warmth-loving) species, e.g. Tilia (lime). From this peak the sequence reverses as the trend to colder conditions predominates.