An ornamental pear in bloom (Images: John Chau)

This week we welcome new CHS contributor John Chau to join Brendan McGarry in bringing you Pikes/Pines, our semi-regular look into the nature of Capitol Hill.

Spring has bloomed. With the mild winter this year, the gardens, parks, and parking strips around Capitol Hill have been filled with life and color again for several weeks already by plants in full flower.

Among the most spectacular and noticeable of these early spring bloomers are the trees. The most common and showy ones are generally either magnolias, which have large flowers with many petals, or members of the rose family. The rose family is a large and important one that can be easy to recognize if you remember that their flowers typically have five petals and many stamens. Three popular trees in this family in bloom now are the ornamental pears, flowering plums, and flowering cherries.

Ornamental pears
Ornamental pears, seen above, are among the first to flower. They generally have white flowers and green leaves that appear when the flowers start to fade. Most ornamental pears belong to one species, Pyrus calleryana, which is originally from Asia. They are commonly called Callery or Bradford pears.

Although well-loved for the beauty of their flowers, they are also notorious for the somewhat unpleasant smell they produce. Ornamental pears are of course closely related to the edible pears we enjoy in the summer and fall (European pear, including ‘Bartlett’, ‘Bosc’, ‘d’Anjou’ – Pyrus communis; Asian pear – Pyrus pyrifolia), but they are also cousins to apples, quinces, and loquats. This whole group within the rose family is distinguished by a unique type of fruit they produce, called a pome, in which the ovary, the structure that produces the seeds, is embedded within additional floral tissue. The result in the mature fruit is a boundary between the outer floral tissue and the inner ovary tissue with the seeds.

A plum flowering plum (Images: John Chau)

Flowering plums
Flowering plums are also very early to bloom, and many trees in the neighborhood are already dropping their petals. There are several kinds of flowering plums, which have white or pink flowers and are all members of the genus Prunus. One of the most common is the cherry plum (Prunus cerasifera), which have a number of cultivars with purple leaves. Although they produce edible fruit, they are generally smaller than those of the common plum (Prunus domestica). Unlike pears, plums and all members of the genus Prunus have ovaries that are held apart from the floral tissue. Their fruits also have a special name, the drupe, in which there is a single seed surrounded by a hard, stony layer (the “pit”).

Flowering cherries
Cherries are probably the most well-known and well-loved of the spring flowering trees. They belong to several species, again all in the genus Prunus. In fact, the genus Prunus contains many plants that we enjoy for their flowers and fruits, including cherries, plums, peaches, nectarines, apricots, and almonds. Flowering cherries typically have white or pink flowers that are produced in clusters on the branch, unlike flowering plums which usually have only one or two flowers at each point along the stem.

Flowering cherry (Images: John Chau)

Cherries also often have trunks with bark marked by a pattern of horizontal lines. These lines, called lenticels, are actually openings in the bark that allow for gas exchange between the inner tissue and the atmosphere. One of the most common flowering cherry species is the Japanese cherry (Prunus serrulata). Flowering cherries have long held cultural importance in Japan. The blooms have come to symbolize the transience of beauty and life, and thousands of people visit parks in spring to participate in the annual flower-viewing tradition, or hanami. With its long history of cultivation, many different varieties have been developed by growers. Of special note are those with what are called double flowers, in which the number of petals has been increased from five to many, creating more of a pom-pom appearance.

With the abundant greenery in the many beautiful parks and residential streets around Capitol Hill, it is easy to have your own “flower-viewing” celebration and enjoy the signs of spring’s return.

To the left a flowering plum, with a flowering cherry on the right (Image: John Chau)