Sweet potato flowering

[bikermike]

A rather fetching purple-blue. Does it matter if they do

[ameno]

It doesn't affect the crop, at least as long as you don't let them set seed (I don't think they can pollinate without a different variety, anyway).
They do look pretty, as you'd expect, seeing as they are the same genus as morning glory. Also, not all varieties will flower. The variety I grew last year had none at all. The one the year before had plentiful flowers from mid-July until October.