But the Rhododendron has species which grow as large trees of height 30 m ( 90 ft ) tall, in forests at altitudes of between 2,500 and 3,000 m or more.
When trekking in Nepal in Dec 2009, I encountered them when trekking through forests on the Ghandruk-Poon Hill trek ( about 3000-3400 m) , where they densely grow as the sole tree species. Their gnarled tree trunks and surface roots speak of their longevity, having witnessed years of snow-fall, frost and countless trekkers who passed through.
At other times, they may dominate the understorey beneath a canopy of taller trees as we traversed in the shady slopes of gorges with rushing rock-bed rivers.
Their size came about in the wild due to the abundant moisture available during the monsoon season, as well as the water from melting snow during spring time in February and March.
Many will take quite a few years to reach flowering. At least fifty years is needed for a tree rhododendron to reach its optimum form. During spring, charming 'candlesticks' are formed by the erect young leaves.
Rhododendron trees blooms in Mar-April in Nepal, so I did not get to see the spectacular sight of their blooming.
The red Rhododendron or Rhododendron arboreum which is called 'Lali Gurans' in Nepali, is the national flower of Nepal.
Rhododendron leaves are light green when young, darker when older.