Native Azalea Identification Scheme
Using Various Flower and Plant Characteristics

Inspired by Bob Stelloh     Internet version by Donald Hyatt

The following scheme for identifying native azaleas was developed by Bob Stelloh using the information provided by Dr. Kathleen A. Kron in her paper published in the Ediniburgh Journal of Botany, Volume 50, Number 3. In Tables 2 and 3 that appear in Dr. Kron's thesis on pages 254-256, she has identified 26 different charactistics of species in the Pentanthera Subsection of the genus Rhododendron, the deciduous azalea species that have five stamens. which includes most of the native azaleas found in the Eastern United States. Using elements from this key, it is possible to clearly differentiate among the various forms. This application currently uses just 12 of those characteristics, the ones identified by Bob Stelloh in his scheme for identifying native azaleas which is presented here in an interactive web application.

When identifying azalea species, the characteristic relating to the Time of Bloom is probably the most important for distinguishing among the various forms, followed next by Corolla Color and Blotch characteristics considered together as a group. Many of the other characteristics are quite subtle, often requiring the use of a magnifying glass or hand lens to observe such things as tiny hairs on the flowers, stems, or bud scales. To help you make your decision, you may click on the Help Page Link button to bring up graphics of representative species having the trait. If you are unable to make a decision, just choose the option "Not Sure" rather than guessing.

After you have made as many selections as possible from the pull down menus, then press the Submit button at the bottom of the page. The application will then give you probabilities (in percent) of deciduous azalea species matching the characteristics that you have identified. The higher to 100%, the more likely the match. There is also a link provided to each of the azalea species with additional information and graphics for your consideration.

Time of Bloom
Do the flowers bloom before or with the new growth as is it expaanding, or do the flowers bloom after the new growth ahas fully expanded?

Corolla, or Flower Color
Is the color of the corolla (the main part of the flower) shades of yellow to ogange or red or shades of pink to white?
Presence of a Blotch
Is there a yellow or gold blotch present on the upper lobe of the flower or is the blotch absent.?
Floral Tube Flare
Does the flower have a long floral tube and then flare gradually or is the tube relatvely short, opening abruptly?
Flower Petal Margin
Are the margins of the petals wavy or are they flat?
Type of Flower Hairs
If the flowers have hairs, are the hairs glandular with sticky glands on the ends or are they eglandular, pointed and fuzzy without glands, or are there both kinds of hairs?
Flower Fragrance
Does the flower have a sweet fragrance?
Sepal Margin
Are the margins of the sepals fringed with fine hairs along the edge or are they bristly with strong stiff hairs?
Help Page Link
Pedicel Hairs
Do the pedicels (stems that connect the flowers to the truss) have sticky glandular hairs or are they eglandular (without glands)?
Help Page Link
Are the stems of the new growth smooth without any hairs or may have some hairs but without glands, or are they noticeably hairy with often sticky glands on the hairs?
Help Page Link
Bud Scale Margins Are the bud scale margins ciliate (or fringed with fine hairs), or are they glandular with bumby edges that are often brownish and look like "shark's teeth"?
Help Page Link
Bud Scale Surface
Is the surface of the bud scales smooth without hairs, sparsely hairy, or are the the bud scale definitely hairy?
Help Page Link

Azalea Species Probability
The Higher the Score, the More Likely the Match

    alabamense     canescens     occidentale
    arborescens     cumberlandense     periclymenoides
    atlanticum     flammeum     prinophyllum
    austrinum     luteum     prunifolium
    calendulaceum     molle     viscosum

Donald W. Hyatt 2002-09-24