These are the fruits of the Viburnum tinus.
This common evergreen shrub is often seen in commercial landscapes because of its durability and long season of interest. The plant in the photo was a hedge. ‘Spring Bouquet’ is a popular cultivar that grows 4 to 6 feet tall. It has small, dark green leaves and white flowers that bloom in winter and early spring. The new growth is reddish, and the fruits are metallic blue. Viburnums are a very diverse group of shrubs.
It is also called laurustine or laurustina, often spelled with one less “u”, Laurestinus or Laurestine; or in French “Le Laurier tin.” It is also known as the Guelder Rose. Laurus signifies the leaves’ similarities to bay laurel; tinus means “tenth born”.. Laurus refers to the leaf having the appearance of bay laurel, & tinus means “tenth born” inferring “late arrival,” an ancient name for an uncertain plant named in old literature, which may well have been Laurustinus named for blooming so late in the year.
A relative of honeysuckle, it is originally from the Mediterranean region of Europe and Africa and Macaronesia. , but has been cultivated in England a very long time & is well adapted to chillier temperate zones that approach zero degrees Fahrenheit in winter. When Shakespeare took a stroll in a pleasant London garden, this very viburnum is one of the plants he was apt to have seen.”
Robert Browning wrote about this plant:
This, that was a book in its time, / Printed on paper & bound in leather Last month in the white of a matin-prime / Just when the birds sang all together. / Into the garden I brought it to read, / And under the arbute & laurustine / Read it, so help me grace in my need, / From title-page to closing line. - Robert Browning Source: Phagat's Gardening