Keith Hammett: The art of plant breeding
Hammett is not a rose breeder. Nevertheless, he raises some issues that are worth discussing.

“A concept conceived with one genus can be extrapolated to another.”

No doubt about it. If doubling occurs in the flowers of one genus, it is likely to occur in another (and does). A reverse bicolor sweetpea led Hammett to work towards reverse bicolor collerette dahlias. We already have reverse bicolor roses, but they could surely be improved.

The other point worth noting is that when we work towards a new trait (whether a color pattern, growth habit or disease resistance) we may not get all we need from a single species.

Hammett started his work on the reverse bicolor sweetpea using various strains of Lathyrus odoratus. He made significant progress. But then, while working with the (then) newly discovered L. belinensis in an effort to raise a yellow sweetpea, Hammett identified "modifier genes from L. belinensis [that] have enabled a much greater contrast between wing and standard colour, as demonstrated in the recently released cultivar ‘Erewhon’.

Similarly, we may not find perfect blackspot resistance as a unit character anywhere in the genus. But there is certainly the possibility of breeding towards resistance by selecting within the various classes of garden roses, then outcrossing to various species to recover useful bits of partial resistance.

Great post Karl. I have long been a fan of what kind of bloom development has occurred in dahlias. Art Nouveau seems to be waiting for this same type of attention.

Thanks for directing us to ‘Art Nouveau’. It is indeed an exciting development worthy of further attention. Frankly, I am surprised that the ‘Roger Lambelin’ pattern could be stabilized at all. How about ‘Baron Girod de l’Ain’?

A couple of other possibilities that should be explored are:

The crisped petals of ‘Permanent Wave’

The reverse bicolors of ‘Jonkheer J. L. Mock’

and ‘Rev. F. Page Roberts’

Just imagine a bicolor or reverse bicolor with both sides visible in the crisped edges.

Regarding the Art Nouveau discussion. Mixing weirdness and weirdness to hopefully get compounded weirdness.

I put 11Z1 pollen on Art Nouveau yesterday, because it has one of the most interesting and/or distinct blossoms in my stable and has above average hardiness. Earlier I put the pollen of a lightly-stippled R. arkansana (hybrid?) that came from David Z. I have an R. arkansana seedling that has a single darker line through the middle of each petal, which is another possiblity.

By the way, I love the crisped edges on Permanent Wave. As you mentioned, Karl, combining that with an contrasting reverse could create striking blossoms.

Selfs of Art Nouveau express very deformed petals with some showing almost no petal tissue at all. Most are very variable combinations of yellow and red, though a few have been solid yellow or red. Crossing it with April Mooncrest, Pretty Lady and Lynnie has produced some extremely resistant and attractive foliage with flowers mainly in red shades.

I recently encountered another example of compounded weirdness.

Griffith Buck got the stippled ball rolling with ‘Applejack’ and some descendants:

Applejack [Goldbusch x (Josef Rothmund x R. laxa Retz.)]
Freckle Face [(Vera Dalton x Dornröschen) x ({World’s Fair x Floradora} x Applejack)]
Grace Note [(Tiki x Marigold) x Freckle Face]
Sevilliana (sibling of Freckle Face) freckled in cool weather

Then Meilland compounded the stippling of ‘Applejack’ with the hand-painting of Sam McGredy IV’s ‘Picasso’.

The Imposter [(Carefree Beauty x Picasso) x (Pink Meidiland x Applejack)]

Brent Dickerson raised a couple of seedlings from ‘Marbrée’. One with pale polka dots was named ‘Papa Vibert’. The other, ‘Jane Welsh Carlyle’, had the edges of its petals distinctly lighter than the bases. This was not due to fading. The petals opened like that.

So, what might happen if such a pale-edged variety were crossed with a hand-painted type? Would dark “brush strokes” be enhanced by the pale back-ground?

At the very least, we now know that ‘Marbrée’ has some hereditary tricks to share.