A Nomenclatural Note
Donald H. Voss
Dr. David F. Chamberlain of the Royal Botanic Garden Edinburgh has informed me (personal communication) of a minor error that appears in several entries in The Genus Rhododendron (1996) . Similar entries appear in The Rhododendron Handbook - 1998 (1997). These entries contain the diminutive variant of the correct epithet for a minor varietas or forma in Rhododendron periclymenoides. In 1900, Porter published Azalea nudiflora var. glandifera and Rehder (1921) made the new combination Rhododendron nudiflorum var. glandiferum. (Under the rules of the Botanical Code, the Linnaean specific epithet nudiflora was illegitimate, and Michaux's periclymenoides must be substituted.)
Porter (1900) described the principal difference of this variety from the type as follows: "Instead of having its peduncles and corolla-tubes clothed with a dense coat of long-acuminate glandless hairs of unequal length, they are sparsely supplied with a single set of gland-tipped hairs of nearly equal length."
In The Genus Rhododendron (pp. 4, 45, 48, 88, and 89) and The Rhododendron Handbook - 1998 (pp. 38, 60, 61, and 62), the diminutive form "glandulifer" was used erroneously in listing certain infraspecific epithets for Azalea nudiflora, Rhododendron nudiflorum, and Rhododendron periclymenoides. In each such instance, glandifera (for Porter's variety in Azalea nudiflora) or glandiferum (for combinations in Rhododendron) should be substituted. Current practice (as shown in The Genus Rhododendron and The Rhododendron Handbook - 1998) does not recognize many of the varieties or forms of yesteryear, and the present name of the glandular Pinxterbloom Azalea named by Porter in 1900 is simply Rhododendron periclymenoides (Michx.) Shinners.
Argent, George, et al. 1997. The Rhododendron Handbook - 1998: Rhododendron Species in Cultivation. London: The Royal Horticultural Society.
Chamberlain, David F., et al. 1996. The Genus Rhododendron: Its classification and synonymy. Edinburgh: Royal Botanic Garden Edinburgh.
Porter, T.C. 1900. Bull. Torrey Bot. Club 27:508.
Rehder, Alfred. 1921. The Azaleas of North America. (In Wilson, Ernest Henry and Alfred Rehder, A Monograph of Azaleas, Publications of the Arnold Arboretum, No. 9, 1921.) Harvard University Press.
Don Voss is a member of the Potomac Valley Chapter and ARS District 9 Director.