Get Growing Blog

Teaming Up to Find the Pinxterbloom Azalea

May 29, 2024


While our coworkers celebrated spring at the arboretum, May 1st found Connor and I, as well as Greg Payton Kady Wilson of the Dawes Arboretum, in Shawnee State Forest in Southern Ohio. We had come not only to try and find a pure Rhododendron periclymenoides, the Pinxterbloom Azalea, but to verify and identify the population data given to us by the Ohio DNR that listed R. periclymenoides as threatened in the state. What made all these goals tricky was that R. periclymenoides loves hybridizing with R. prinophyllum, the Northern Roseshell Azalea, and the differences between the two are quite minuscule. Besides the seed heads, the only way we knew to tell the difference was the tiny hairs upon the collora tubes. Northern Roseshell has corolla hairs with tiny club-shaped glands while Pinxterbloom hairs have none. With our herbarium presses at hand, we piled into the van and headed into the woods.

Our stops in Shawnee found us scratching our heads. While there were plenty of pink azaleas at hand, it was difficult to guess which species they belonged to, but most seemed to be hybrids or pure Northern Roseshell. We peered through our hand lenses at tiny hairs and sniffed open flowers until we wished for coffee beans to clear our sinuses. I was overjoyed at the number of pink and yellow lady slipper orchids we found growing near the azaleas; both acid-loving and shade dwelling plants. Eastern Tiger and Spicebush Swallowtails flitted throughout the understory. After collecting several specimens, it was time to head to our next destination: Wayne National Forest.

The golden rays of pre-dawn lit our way as we hiked along the rocky trail. Our first stop within a steep ravine seemed destined to yield no azaleas, either Pinxterbloom or Roseshell. Yet we continued until we came to a small stream, and there we found it. A pure Rhododendron periclymenoides. The pale-pink, star-shaped flowers and sweet fragrance were so different from all the hybrids and pure rosehsells we had found that it could only be the one we had been seeking. Opening our presses once more, we detailed the shrub and its surrounding vegetation before wearily making our way back to the van.

This is just the first of more trips we plan to make in the coming months and years as we determine the full extent of each species in the state. This summer we plan to journey to populations within Northeast Ohio and back to Southern Ohio to collect seed for our conservation and research purposes.

Kara Grady

Kara Grady

Conservation Horticulture Assistant, NOWCorps

Here’s more to explore

View all

What can we help you find?

Return to site

Debug info for popularity tracking: Disable within popularity-tracking.php file once ready.

Time: 1719273600 / Saved: 1719273600

Views (7 day(s) ago): 5

Views (6 day(s) ago): 9

Views (5 day(s) ago): 1

Views (4 day(s) ago): 3

Views (3 day(s) ago): 0

Views (2 day(s) ago): 3

Views (1 day(s) ago): 5

Views (Today): 1