Rhododendron

The name Rhododendron comes from the greek words "rodon" which means "rose" and "dendron" which means "tree", hence Rose Tree. Rhododendron flowers are usually produced in trusses. The family Ericacea, into which the genus Rhododendron falls, also includes heathers, mountain laurels, blueberries and cranberries as well as manzanita, trailing arbutus, madrone, huckleberry, kalmiopsis, sourwood, blueberries and a number of other genus. Rhododendrons are referred to as the King of Shrubs since they are regarded by many as the best flowering evergreen plants for the temperate landscape.

Kingdom

Plantae

Sub Kingdom

Tracheobionta

Super Division

Spermatophyta

Division

Magnoliophyta

Class

Magnoliopsida

Sub Class

Dilleniidae

Order

Ericales

Family

Ericaceae

Genus

Rhododendron L.

Facts About Rhododendron

• Most people know rhododendrons as big leathery leafed shrubs with round clusters of white, pink, red, or purple blooms.
• Rhododendron was discovered by The 16th century Flemish botanist, Charles l'Ecluse.
• Rhododendron was introduced to Britain in 1656 from the European Alps, and so the name Alpine Rose for Rhododendron histrum.
• Exploration in America came as a result of a partnership between English Quaker Peter Collinson and botanist/farmer John Bartram of Pennsylvania. This led to the importation to England of the American natives, Rhododendron canescens, Rhododendron nudiflorum, and Rhododendron viscosum in 1734, and Rhododendron maximum in 1736.
• Rhododendron ferrugineum, another species from the European Alps also known as the Alpine Rose, came along in 1752.
• The Washington State Senate confirmed that the Coast Rhododendron / Pacific Rhododendron (Rhododendron macrophyllum) would be the floral emblem for Washington state.
• Rhododendron is also the national flower of Nepal, and the state flower of Sikkim in India.
• All the parts of Rhododendrons are dangerous, especially leaves, showing symptoms of Stomach irritation, abdominal pain, abnormal heart rate and rhythm, convulsions, coma, death. Honey made from the nectar of Rhododendron flowers is also toxic and should not be consumed.

What is the difference between Rhododendrons and Azaleas?

• The genus Rhododendron includes both Rhododendrons and Azaleas. In this genus, both Rhododendron and Azalea are used as common names. The distinctions that follow are made by gardeners. The Rhododendron plants are usually evergreen and those labeled Azalea plants are deciduous, although there are a few evergreen Azaleas like those in the florist or nursery trade. To the typical gardener, azaleas are conspicuous because they don't have trusses. The exception to this is the Homebush type azaleas which have a very tight ball shaped truss but this type of azalea is deciduous. It should be mentioned that the tropical Vireya rhododendrons don't have a truss either and look more like azaleas but are in general treated as a special class, different from most other rhododendrons and azaleas.
• Rhododendrons have ten or more stamens, while Azaleas have five.
• Rhododendrons have large, paddle-shaped leaves and large, bell- or funnel-shaped flowers borne in terminal trusses. Azaleas have small, elliptical leaves and trumpet- or tubular-shaped flowers at the ends of the shoots. Still some rhododendrons, called lepidoes have small leaves and small flowers and some rhododendrons are naturally miniature have miniscule leaves and flowers. It is true that all azaleas have small leaves compared to the large leaved rhododendrons, the elepidotes.
• Rhododendrons are erect, growing up to 80 feet high, while Azaleas are more twiggy, spreading bushes, usually reaching a height of no more than 8 feet.
• Both Rhododendrons and Azaleas provide fragrant blossoms in an array of colors - from pure white and light pastels to brilliant orange and gold to purple and red. Some blossoms change color over time or are marked with contrasting colors.