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.
Rhododendron. RHODODENDRON. Throughout June and July the colorful flowers and shining foliage of the rhododendron beautify the mountain slopes of North America. The flowers are pink, rose, lilac, or purple. The species usually found in the East is the American, or great, rhododendron. The Carolina, or Catawba, rhododendron grows in the high Appalachians. A species called coast rhododendron is found on the Pacific coast (for picture in color, see Flowers, Wild Flowers).