[Rhododendrons and Labrador Teas of the Columbia River Gorge of Oregon and Washington]

Cascade Azalea, White Rhododendron, White-flowered Azalea

Rhododendron albiflorum

Synonyms: Azaleastrum albiflorum, Azaleastrum albiflorum ssp. warrenii, Rhododendron albiflorum var. albiflorum, Rhododendron albiflorum var. warrenii

Cascade Azalea, White Rhododendron, White-flowered Azalea: Rhododendron albiflorum (Synonyms: Azaleastrum albiflorum, Azaleastrum albiflorum ssp. warrenii, Rhododendron albiflorum var. albiflorum, Rhododendron albiflorum var. warrenii)

The photo above shows a close-up of the flower cluster and new years growth fo leaves of western azalea as seen at the summit of Potato Hill to the north of Mt. Adams........July 11, 2005.

Sideview of the calyx and corolla of Cascade Azalea, White Rhododendron, White-flowered Azalea: Rhododendron albiflorum (Synonyms: Azaleastrum albiflorum, Azaleastrum albiflorum ssp. warrenii, Rhododendron albiflorum var. albiflorum, Rhododendron albiflorum var. warrenii)The photo at right shows a close-up of the sepals and corolla of western azalea as seen at the summit of Potato Hill to the north of Mt. Adams........July 11, 2005.
Characteristics:

An attractive plant suitable for the moist woodland garden, western azalea is a branched shrub from 1-2 meters high. The stems are covered with minute hairs or longer but appressed, stiff hairs which are reddish. These hairs extend onto the young leaves, bracts, and calyx. The deciduous leaves are thin with deep green upper blades and lighter green below. The blades are elliptic-oblanceolate in shape with entire to wavy margins. They are 4-9 cm long with petioles from 5-10 mm long. The leaves are sparingly pubescent, especially with age when they may appear fairly shiny (See photos.).

The inflorescence consists of clusters of 1-5 nodding flowers in axillary clusters near the tips of the branches. The pedicels are about 1-1.5 cm long and covered with glandular hairs as well as coarse red hairs that are appressed to the pedicels. The Calyx is divided to the base into 5 leafy, oblong lobes about one-half as long as the corolla. The calyx is also covered with a mix of coarse glandular hairs and red, appressed hairs. The corolla is also 5-lobed, the divisions only to about mid corolla. The corolla is white or cream in color and about 1.5-2 cm long, with the rounded lobes spreading. The 10 stamens are shorter than the corolla and are densely haired on their lower half. The anthers are ovoid in shape. The ovary is 4-5 celled and covered with long hairs. The fruits are short, ovoid capsules from 6-8 mm long with thick walls.


Habitat:

White rhododendron may be found at higher elevations in the mountains in moist forests, especially along streams.


Range:

White rhododendron may be found from British Columbia south to Oregon and east to western Montana and Alberta. In eastern Oregon, it is found at higher elevations in the Blue Mts.


Flower of Cascade Azalea, White Rhododendron, White-flowered Azalea: Rhododendron albiflorum (Synonyms: Azaleastrum albiflorum, Azaleastrum albiflorum ssp. warrenii, Rhododendron albiflorum var. albiflorum, Rhododendron albiflorum var. warrenii)

The photo above shows a frontal view of the flower of western azalea as seen atop the summit of Potato Hill several miles to the north of Mt. Adams........July 11, 2005. Note the 10 stamens as well as the golden-yellow spots on the upper half of the inner surface of the corolla.

Cascade Azalea, White Rhododendron, White-flowered Azalea: Rhododendron albiflorum (Synonyms: Azaleastrum albiflorum, Azaleastrum albiflorum ssp. warrenii, Rhododendron albiflorum var. albiflorum, Rhododendron albiflorum var. warrenii)


Paul Slichter