本文发表在 rolia.net 枫下论坛Rhododendron is a family of flowering shrubs that includes both rhododendron and azalea varieties. All azaleas are rhododendrons but not all rhododendrons are azaleas. The two species within the genus differ in plant traits.
Classification
According to the new classification updates of the Balfourian System, besides being classified as a Rhododendron, azalea has been grouped under the subgenus Pentanthera (to indicate its deciduous nature) and subgenus Tsutsusi (to indicate its evergreen foliage).
Leaves
Azaleas have typical features in the form of small hair-like structures. These hairs are found growing parallel to the leaf’s surface. This feature can be clearly seen on the midrib of the leaf, i.e. along its underside. The evergreen variety of azaleas has a visible hair growth pattern. However, rhododendrons don’t have hair-like growth but they do have small, scaly dots, found underneath the leaf. Some rhododendrons may have oblong spots that may be confused with sticky, thick hair-like projections but an azalea leaf will never be dotted or have scales. The commonest varieties of azaleas are deciduous, i.e. they shed their leaves in the winter season. Except R. dauricum and R. mucronulatum, all rhododendrons are evergreen.
Flowers
The flower size and flowering patterns of these shrubs is very different. Azaleas have slightly smaller and slender, funnel-shaped flowers. The flowers of true rhododendrons are bell-shaped and much bigger. Azaleas tend to have just one flower per stem, known as terminal blooming. Most garden rhododendrons have their flowers in small batches, in a clustered formation. Azaleas are more seasonal in nature, in terms of flowering, i.e. their flowers have a particular time for blooming. Garden azaleas tend to have the best foliage during the onset of the spring season. Except a few varieties, rhododendrons tend to maintain some degree of flowering throughout the year with some periods of dense flower sprouting.
Toxicity
Some azalea plants are known to be toxic to herding animals due to a peculiar kind of toxin. None of the rhododendrons are known to be toxic.
Stamen Structure
Most azaleas will have just one stamen on each of the flower lobe. Since they have five lobes in total, these shrubs characteristically have five stamens. However, rhododendrons tend to have two or more stamens per lobe. Thus, their total stamen count is 10 or more.更多精彩文章及讨论，请光临枫下论坛 rolia.net
Classification
According to the new classification updates of the Balfourian System, besides being classified as a Rhododendron, azalea has been grouped under the subgenus Pentanthera (to indicate its deciduous nature) and subgenus Tsutsusi (to indicate its evergreen foliage).
Leaves
Azaleas have typical features in the form of small hair-like structures. These hairs are found growing parallel to the leaf’s surface. This feature can be clearly seen on the midrib of the leaf, i.e. along its underside. The evergreen variety of azaleas has a visible hair growth pattern. However, rhododendrons don’t have hair-like growth but they do have small, scaly dots, found underneath the leaf. Some rhododendrons may have oblong spots that may be confused with sticky, thick hair-like projections but an azalea leaf will never be dotted or have scales. The commonest varieties of azaleas are deciduous, i.e. they shed their leaves in the winter season. Except R. dauricum and R. mucronulatum, all rhododendrons are evergreen.
Flowers
The flower size and flowering patterns of these shrubs is very different. Azaleas have slightly smaller and slender, funnel-shaped flowers. The flowers of true rhododendrons are bell-shaped and much bigger. Azaleas tend to have just one flower per stem, known as terminal blooming. Most garden rhododendrons have their flowers in small batches, in a clustered formation. Azaleas are more seasonal in nature, in terms of flowering, i.e. their flowers have a particular time for blooming. Garden azaleas tend to have the best foliage during the onset of the spring season. Except a few varieties, rhododendrons tend to maintain some degree of flowering throughout the year with some periods of dense flower sprouting.
Toxicity
Some azalea plants are known to be toxic to herding animals due to a peculiar kind of toxin. None of the rhododendrons are known to be toxic.
Stamen Structure
Most azaleas will have just one stamen on each of the flower lobe. Since they have five lobes in total, these shrubs characteristically have five stamens. However, rhododendrons tend to have two or more stamens per lobe. Thus, their total stamen count is 10 or more.更多精彩文章及讨论，请光临枫下论坛 rolia.net