These innocent looking little beauties are, in reality, sinister little
creeps. They are alien, in the same family, Convolvulaceae, as sweet
potatoes (Ipomoea batatas). They are now in bloom at lower elevations,
and are leafing out up here.
My recommendation for these is to control the surface expression, as you
cannot control its deep roots. Just pull them as you find them, and
don't make yourself nuts.