The epidermis of petals also form a variation of trichomes called conical cells. These cells all develop from the pavement cells, which make up the majority of the plants surface cells. In short, cellular differentiation of the epidermal cells is controlled by two major factors: genetics and environmental conditions.
Azaleas and rhododendrons thrive in acidic soil. Azaleas and rhododendrons thrive in the acidic soil that is common under pine trees. Both plants are classified under the genus Rhododendron; the main difference is the smaller, funnel-shaped flowers on the azalea.ake soil samples from the area under the trees where you want to plant the azaleas or rhododendrons. Mix the samples in a bucket and test with a soil pH test kit.
One popular type of deciduous shrub rhododendron, the snow azalea (Rhododendron mucronulatum), is hardy in USDA plant hardiness zones 5 to 9. It has pink or purple flowers and can grow up to 10 feet tall.It often has leggy growth, however, and remains around 5 feet tall.hey stay between 6 inches and 3 feet tall and have purple blooms. Cloudland rhododendrons are hardy in USDA plant hardiness zones 4 to 7. Another type of rhododendron that grows well indoors is Rhododendron (subgenus Azalea) 'Brazil.' It is an azalea with orange flowers, hardy in USDA zones 5 to 8.