Scores toured the Arnold Arboretum's collection of fragrant flowers today for the annual Lilac Sundays celebration, and despite the damp weather it was a picture-perfect Mother's Day afternoon.

The species of carefully tended plantlife at the Harvard-run arboretum number in the tens of thousands. As spring rolls in, the collection has started to bloom.

Tours are available on the weekends or on weekdays by appointment, and the arboretum's spring calendar is  full of special events. Lilac Sundays have been a tradition at the destination for more than a century