QBARS - v26n4 Distribution of Catawba Rhododendrons at Low Elevations - Part II

Distribution of Catawba Rhododendrons
At Low Elevations - Part II
Robert L. Schwind, Atlanta, Georgia

In an article appearing in the July 1971 issue of the ARS Quarterly Bulletin, the writer considered certain forms of Catawba rhododendrons growing at low elevations in eastern Carolina which were described by Dr. W. C. Coker of the University of North Carolina at Chapel Hill and designated by him as R. catawbiense var. insularis in the October 1919 issue of the Journal of the Mitchell Society . Dr. Coker felt that the varietal name "insularis" was justified by virtue of certain of its morphological differences as well as its adaptation to hotter climatic conditions existing in the Piedmont and coastal plains of North Carolina, a claim of distinction to which some other botanists might not assent.

In mid-year of this year, as last, the writer in the company of his son and Dr. Herbert Hechenbleikner of the University of North Carolina at Charlotte visited some colonies of lower elevation Catawba rhododendrons in Stokes County, North Carolina. Like those described last year near Chapel Hill, Wilson, and Lillington, the colors of pink, lavender and magenta predominated. However, in Stokes County one white form was found from which hand-pollenated seeds and cuttings will be taken later. The shrubs were generally large and favored northern and eastern exposures, and at times were found growing with R. maximum along the banks of streams.

Following the inspection of the Stokes County colonies, the writer and his son journeyed eastward to Johnston County, where, accompanied by Bill Ragsdale of Smithfield, they inspected a colony of Catawba rhododendrons on the west bank of the Neuse River at an elevation of 150 feet above sea level. This is the lowest elevation at which this form of Catawba Rhododendron has yet been found. The members of this colony in all of their obvious characteristics of shrub size and habit, color range, and blooming time were indistinguishable from the form found near Chapel Hill and Wilson and described last year. At the appropriate time, seeds and cuttings will be taken from this colony to add to the growing gene pool of Dr. Coker's R. catawbiense var. insularis which is being distributed throughout the world as a source of heat-tolerance and root rot resistance needed so dearly in warmer, less favorable parts of the world where rhododendron culture is being tried.

While visiting Bill Ragsdale in Smithfield, the writer was astonished to learn of the variety of rhododendron hybrids, some well known and others obscure, which he is growing and propagating in the torrid coastal plains of eastern Carolina, often in full sun. It was indeed an anomaly to see rhododendron hybrids growing along side of tung trees, an oriental import grown commercially in northern Florida for its oil. Bill is intent on proving that many of our notions about rhododendron culture and adaptability in warmer parts of the country are not necessarily so.

From pollen gathered last year from the low-elevation Catawba colonies near Chapel Hill, Wilson and Lillington, the writer effected a number of crosses with good quality hybrids well suited to the South. Numerous vigorous seedlings are coming along well which will be tested for heat-tolerance and root rot resistance and also their floral qualities. More crosses were made this year for further testing in an continuing effort to overcome some of the obstacles limiting rhododendron culture in the South.