Guest potato variety

[Plot70]

Last year a guest potato sprouted up and produced a modest crop of purple skinned tubas.
All tomatoes and peppers outside and inside got blight but this plant appeared to be resistant. I am going to save some tubas for next year.
I would like to find out what variety they are so that I can plant and harvest them at the correct times.
The flowers are purple and the stems have streaks of purple on them.
The tubas are purple when damp and volcanic grey when dry. The flesh of the tubas is copier paper white right up to the skin with no shaded margin.

[Nicos]

What have you grown in recent years? Or, what have your plot neighbours grown ( if relocated by rats etc)

My guess would be Desiree

I checked this out….
https://www.europotato.org/varieties/view/Desiree-E

[Mr Bones]

Could they be Sarpo Blue Danube
https://www.google.co.uk/search?q=sa...ih=852&dpr=1.1

[ameno]

Could they be Sarpo Blue Danube
https://www.google.co.uk/search?q=sa...ih=852&dpr=1.1

Wait, Blue Danube is white on the inside?
Damn, that's very disappointing. I was thinking of getting some next year thinking it was blue/purple all the way through. Well, at least I know not to get any now.

[Plot70]

The flowers and stalk colour look right for sarpo blue danube.
The disease resistance claims match what I have seen on the plot.
I have had the plot since winter 2019 and there have been a few spuds sprouting up each season.
It was an odd one that came up in a place where I left it to crop.
I left another roasting variety that had huge tubas that turned out to be hollow and full up with slugs... Useless.
What I have has clearly been growing through weeds during a period of neglect before I took on the plot.