Notes on Rhododendron coryi
Dr. Sigmund L. Solymosy
Professor of Horticulture, University of Southwestern Louisiana
Rhododendron coryi was named by Lloyd Shinners after its collector V. L. Cory who discovered and collected the first specimen on April 18, 1950 (Cory 57145) in Tyler county, Texas. This was followed by two more collections on April 19, 1950 (Cory 57191) and (Cory 07207) in Hardoin and Newton counties respectively. My first encounter with this plant took place in 1951. Without looking specifically for it, I found it east of the Menard Creek bridge off FMR 943 in Hardin county. I identified it tentatively and hastily as a dwarf clone of Rhododendron oblongifolium. At that time, the literature on Rhododendron in Texas and Louisiana was vague and incomplete. Even today, 20-25 years later, opinions differ considerably concerning the Texas-Louisiana Rhododendrons: R. coryi, R. oblongifolium, R. viscosum, R. viscosum v. glaucum and R. serrulatum. The only generally accepted feature is that they all flower after the leaves have fully developed. During my studies of Rhododendron from the Herbarium of the Louisiana State University I noticed a R. coryi specimen collected in Washington parish. In the mid-sixties, I attempted to disengage and untangle the overlapping and inconstant characteristics of the "whites." I have to admit that this venture turned out to be an almost hopeless venture right at the beginning. Very slowly, after repeated critical studies a few characteristics began to crystallize, only to be obscured by newly appearing common denominators. With this, the hope of constructing a foolproof key for the "whites" faded away and put me in the distinguished group of noted colleagues who tried but never succeeded to construct a foolproof key - for the taxa of the subgenus Anthodendron, Series Luteum.
I visited Dr. Shinners in 1965 at the Southern Methodist University Herbarium in Dallas. Texas. The question of the status of R. coryi was discussed extensively and at length. Dr. Shinners asked my opinion about the status of that new addition to the "whites". I mentioned to him that I was working - through the elimination of characteristic features - on a "negative" key according to which the "whites", including R. coryi might be separated without being able to classify it properly.
R. coryi is not: R. oblongifolium because, the latter is not stoloniferous and has conspicuous oblong leaves on the current year's sterile growth. (Similar to R. canescens)
R. coryi is not: R. serrulatum, because R. serrulatum has a typical, white, underground creeping stem system.
R. coryi is not: R. atlanticum, because this latter does not occur in Texas and Louisiana. (Plants for this area were reported erroneously.)
R. coryi is not: R. viscosum var. glaucum, because this taxon has glaucous leaves
This leaves us with R. viscosum; the efflorescence coincides with that of R. coryi, both are stoloniferous; the leaves differ only in size: R. coryi has smaller leaves. The flowers of both are either lemon scented or have a musky odor.
Some pink setae occur sporadically on R. coryi, and on R. viscosum. The difference between the two is only the smaller size and the smaller plant parts. I came to the conclusion related to Dr. Shinners that R. coryi does not deserve a specific rank. It may be a variety of the rather abundant R. viscosum, The occurrence of R. coryi may be compared to the "Dwarf Oconee, of Georgia. a small stoloniferous clone of R. speciosum.