September Color Appears at the Washington Park Arboretum
(Part II)

October 3rd, 2011 by Pat Chinn-Sloan

Species of Sorbus are commonly known as whitebeam, rowan, service tree, and mountain ash. All these cuttings are from the Brian Mulligan Sorbus Collection, located to the east of Arboretum Drive across from the Magnolia Collection.

Selected cuttings from the Washington Park Arboretum for September 19-October 3, 2011

Selected cuttings from the Washington Park Arboretum (September 19 – October 3, 2011)

1) Sorbus aucuparia (European Rowan)

  • Sorbus aucuparia is native to most of Europe except for the far south, and northern Asia.
  • It is listed as a ‘Weed of Concern’ by the King County Noxious Weed Board because of its propensity to spread seeds far and wide via birds.
  • This specimen was collected from the last remaining Sorbus aucuparia, which fell over during the past weekend.

2) Sorbus commixta (Japanese Rowan)

  • Sorbus commixta is a species of rowan native to Japan, the far east of Russia on Sakhalin, and in Korea on the island of Ulleungdo.
  • Performs very well in the Pacific Northwest, producing large crops of berries.
  • While unappetizing to humans, birds (especially robins) can denude a tree of berries in a day.

3) Sorbus prattii

  • Sorbus prattii is a Chinese rowan bearing small corymbs of white flowers in late spring followed by green berries that ripen to white.

4) Sorbus tamamschjanae

  • A little known red-berried, simple-leafed Rowan from Armenia.

5) Sorbus vestita (Himalayan Whitebeam)

  • Broad and conical tree with sharply toothed leaves, that has corymbs of white flowers that bloom in late spring followed by yellowish-green berries with brown freckles.