Hi ! In today's Post, Here are some fresh Rhododendrons blooming on recent stamps issued by Canada. Rhododendrin is a beautiful flower found in many bright colors. India has also issued a stamp on Rhododendron in 1977. I am also showing that stamp below. I have also serched two lovely stamps issued by Poland on Rhododendron. I am very pleased to write that Rhododendrons are also found in Himachal Pradesh specially in Shimla hills. These lovely flowers can be seen on way to Shimla. I am giving more details about this flower below. This is a flowering Post for Today ! ......Till Next Post..........Have a Nice Time !
Rhododendron (from the Greek: rhodos, "rose", and dendron, "tree") is a genus of flowering plants in the family Ericaceae. It is a large genus with over 1000 species and most have showy flower displays. It includes the plants known to gardeners as azaleas. It is the national flower of Nepal.
The Rhododendron is a genus characterized by shrubs and small to (rarely) large trees, the smallest species growing to 10-100 cm tall, and the largest, R. giganteum, reported to over 30 m tall. The leaves are spirally arranged; leaf size can range from 1-2 cm to over 50 cm, exceptionally 100 cm in R. sinogrande. They may be either evergreen or deciduous. In some species the underside of the leaves is covered with scales (lepidote) or hairs (indumentum). Some of the best known species are noted for their many clusters of large flowers. There are alpine species with small flowers and small leaves, and tropical species such as section Vireya that often grow as epiphytes
Distribution
Rhododendron is a very widely distributed genus, occurring throughout most of the Northern Hemisphere except for dry areas, and extending into the Southern Hemisphere in southeastern Asia and northern Australasia. The highest species diversity is found in the Himalayan mountains from Uttarakhand, Nepal and Sikkim to Yunnan and Sichuan, with other significant areas of diversity in the mountains of Indo-China, Korea, Japan and Taiwan. In addition, there are a significant number of tropical rhododendron species from southeast Asia to northern Australia, with 55 known species in Borneo and 164 in New Guinea. [2] Relatively fewer species occur in North America and Europe. Rhododendrons have not been found in South America or Africa.
Rhododendron is a very widely distributed genus, occurring throughout most of the Northern Hemisphere except for dry areas, and extending into the Southern Hemisphere in southeastern Asia and northern Australasia. The highest species diversity is found in the Himalayan mountains from Uttarakhand, Nepal and Sikkim to Yunnan and Sichuan, with other significant areas of diversity in the mountains of Indo-China, Korea, Japan and Taiwan. In addition, there are a significant number of tropical rhododendron species from southeast Asia to northern Australia, with 55 known species in Borneo and 164 in New Guinea. [2] Relatively fewer species occur in North America and Europe. Rhododendrons have not been found in South America or Africa.
Toxicology
Some species are poisonous to grazing animals. These Rhododendrons have a toxin called grayanotoxin in their pollen and nectar. People have been known to become ill from eating honey made by bees feeding on rhododendron and azalea flowers. Xenophon described the odd behavior of Greek soldiers after having consumed honey in a village surrounded by rhododendrons. Later, it was recognized that honey resulting from these plants have a slightly hallucinogenic and laxative effect. Rhododendron is extremely toxic to horses, with some animals dying within a few hours of ingesting the plant, although most horses tend to avoid it if they have access to good forage.
Some species are poisonous to grazing animals. These Rhododendrons have a toxin called grayanotoxin in their pollen and nectar. People have been known to become ill from eating honey made by bees feeding on rhododendron and azalea flowers. Xenophon described the odd behavior of Greek soldiers after having consumed honey in a village surrounded by rhododendrons. Later, it was recognized that honey resulting from these plants have a slightly hallucinogenic and laxative effect. Rhododendron is extremely toxic to horses, with some animals dying within a few hours of ingesting the plant, although most horses tend to avoid it if they have access to good forage.
Use in landscaping
Both species and hybrid rhododendrons (including azaleas) are used extensively as ornamental plants in landscaping in many parts of the world, and many species and cultivars are grown commercially for the nursery trade. Rhododendrons are often valued in landscaping for their structure, size, flowers, and the fact that many of them are evergreen . Azaleas are frequently used around foundations and occasionally as hedges, and many larger-leafed rhododendrons lend themselves well to more informal plantings and woodland gardens, or as specimen plants.
Both species and hybrid rhododendrons (including azaleas) are used extensively as ornamental plants in landscaping in many parts of the world, and many species and cultivars are grown commercially for the nursery trade. Rhododendrons are often valued in landscaping for their structure, size, flowers, and the fact that many of them are evergreen . Azaleas are frequently used around foundations and occasionally as hedges, and many larger-leafed rhododendrons lend themselves well to more informal plantings and woodland gardens, or as specimen plants.
Commercial growing
Rhododendrons are grown commercially in many areas for sale, and are occasionally collected in the wild, a practice now rare in most areas. Larger commercial growers often ship long distances; in the United States most of them are located on the west coast (Oregon, Washington and California).
Rhododendrons are grown commercially in many areas for sale, and are occasionally collected in the wild, a practice now rare in most areas. Larger commercial growers often ship long distances; in the United States most of them are located on the west coast (Oregon, Washington and California).
Planting and care
Like other ericaceous plants, most rhododendrons prefer acid soils , some tropical Vireyas and a few other rhododendron species grow as epiphytes and require a planting mix similar to orchids. Rhododendrons have fibrous roots and prefer well-drained soils high in organic material. In areas with poorly-drained or alkaline soils, rhododendrons are often grown in raised beds using mediums such as composted pine bark. Mulching and careful watering are important, especially before the plant is established.
Like other ericaceous plants, most rhododendrons prefer acid soils , some tropical Vireyas and a few other rhododendron species grow as epiphytes and require a planting mix similar to orchids. Rhododendrons have fibrous roots and prefer well-drained soils high in organic material. In areas with poorly-drained or alkaline soils, rhododendrons are often grown in raised beds using mediums such as composted pine bark. Mulching and careful watering are important, especially before the plant is established.
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