A Seven Sisters Phenomenom now named “Seven Brothers”

Darrell Schramm, Editor of the HRG's The Rose Letter, invited me to visit his garden where I saw this rose and he asked me if I knew it's identity? It wasn't in bloom but the distinctive frilled stipules and light green rugose leaves looked identical to my 'Seven Sisters' rose. Sometime later he told me it bloomed small single red flowers, I was astonished!
From cuttings of his plant I grew it in my garden and indeed the first flowers were single. But within a year or two semidouble ones began to appear but so far none like the double flowers on my original 'Seven Sisters'. What was happening here? A chimera, sport or reversion? Of the many photos of 'Seven Sisters' posted at HMF, none show single or semidouble flowers, so it seems pretty rare.
In the 'Seven Sisters' references I learn the rose was also passed around by seed in the 1800's so possibly this is simply seedling variation. And among the six pages of HMF references I only find two sources mentioning single to semidouble flowers, August Jäger's Rosenlexikon [1936] and Robert Buist's The Rose Manual (1844). So, I shall keep you posted whether my plant eventually produces the typical double flowers but in the meantime I'll continue to enjoy my phenomenal “Seven Brothers”.

There were/are two distinct varieties traveling under the same name. The first was double with flowers that varied widely in color upon opening..

The second was a smaller, weaker (or creeping) plant with single white flowers. It was also listed as Rosa Roxburghii, R. Roxburghiana or Roxburgh's Single White Multiflora.

Laffay thought the latter was the "type" of the Multiflora roses (according to Mrs Gore, 1838.)

Roxburgh's Rosa diffusa, "is readily known by its weak, diffuse and procumbent, very long, almost simple branches, which often rest on the ground; it is supposed to be a native of China, as it was brought from Canton to the Botanic garden at Calcutta."