Syringa can be deciduous shrubs or trees, with simple, entire or rarely pinnate leaves and conical panicles of small, very fragrant, 4-lobed tubular flowers in late spring or early summer
'Katherine Havemeyer' is an upright medium-sized deciduous shrub becoming spreading with age, with mid-green, heart-shaped leaves and compact panicles of fragrant, double, lavender-purple flowers which fade to lilac-pink