Rhododendron thomsonii subsp. thomsonii
Common name: 
Thomson Rhododendron
ro-do-DEN-dron tom-SON-ee-i
Rhododendron thomsonii
Native to (or naturalized in) Oregon: 
  • Broadleaf evergreen upright, open shrub or small tree, 5 ft (1.5 m) in 10 years, finally to 14 ft (4.3 m) high with a greater spread, red peeling bark.  Leaves alternate, simple, 5-10 cm long, about 2/3rds as wide, orbicular or oval or elliptic, rounded at the tip, but may have a short, abrupt tip, rounded or cordate (heart-shaped) at the base, dark green above, bluish-white or glaucous green below.  Flowers about 6 cm long and wide, bell-shaped, crimson to a deep wine red, 6-12 in loose, terminal clusters; calyx conspicuous, 12-19 mm deep; 10 glabrous stamens.
  • 5°F, early-mid, 3/2-4/3-4.  [flower / plant & foliage / performance; scale 1 (poor) - 5 (best)]  Native to the Himalaya --- Nepal, India (Sikkim, Arunachal Pradesh), southern Tibet,and Bhutan.
  • thomsonii: after Thomas Thomson (1817-1878), Scottish physician and superintendent of the Calcutta Botanic Garden.
  • Federal Way, Washington: Rhododendron Species and Botanical Garden.
Click image to enlarge
  • plant habit, flowering

    plant habit, flowering

  • flower cluster

    flower cluster

  • flower clustser, top view

    flower clustser, top view

  • leaf and flower calyx

    leaf and flower calyx