'Epoch' is a tetraploid R. carolinianum, which Augie created by treating the seed with colchicine to double the number of chromosomes. He says "Tetraploids in general have much larger flowers than diploids. In addition, the flower texture is thicker, and hence, the lasting quality of the flower is improved." 'Epoch' is a popular parent for further hybridization. The plant pictured here is the same cross as 'Kehr's White Ruffles' described below.
'Kehr's White Ruffles'(ARS 974): Lepidote rhododendron. ('Epoch' x white-flrd mucronulatum). H(1977), G(1979), N(1997), and REG(1997): August E Kehr, Hendersonville NC. Fls 2-3/flat truss, openly funnel-shaped, c1.75" long x 2.5" wide, 5-lobed with frilled margins; white in bud, opening white inside and out, with greenish dorsal blotch. Truss x3" high x c3.5" wide. Lvs held 3 years, elliptic, flat, cuneate base, acuminate tip, 5" x 1.75"; deep green and sime-glossy above, with scales below. Shrub 4' tall x 7.5' wide in 10 years, dense growth habit. Plant hardy to at least -15°F; buds -10°F. Early.