The bright yellow flowers of Cornus mas, or Cornelian Cherry Dogwood, have opened on the Boulevard. Its blooms, on leafless branches, are smaller than witchhazel. Noted for attracting wildlife, its nectar is gathered by bees, and ovoid red fruits will be enjoyed by birds when ripe in June. There’s one large, old shrub near Laurel Avenue, and two new small ones farther toward Swan point. They have also been spotted at Upton and Mount Avenues.