if i understand your question ...

you have harvested 'open pollinated' seed ... off an unnamed plant ...

and you want to know the 'cultivar name' of the potential seedlings ...

is a non sequitor ... as a CULTI-VAR ... cultivate varietal's definition ... has certain meanings ....

stated another way ... not many things.. come true from seed ... and its usually the species plants.. as that is part of the definition of being a species ...

perhaps you could research if there are any white species Althea ... [ever wonder why this plant has two female names????] .. sharon and althea???? ... crikey.. Rose also.. 3 names ....lol]

anyway .. i digress ... i dont think there is an answer to your question ...

good luck with your seeds.. if you come out with some magnificent cultivar ... maybe you can name it ... try for a 4th female name ... lol

maybe in a decade or two... you can talk some wholesale grower.. to put it into production .... though i am not sure we need another self sowing ROS ....

ken

Here is a link that might be useful: link

Any member of the hibiscus family, including rose of sharon is extraordinarily easy to start from cuttings. I've a pure white one that I started from cuttings.