They have white flesh.
The taste is not particularly good, but the plant delivers high yields.
These are waxy potatoes.
History Notes
Lumper Potatoes were introduced into Munster, Ireland about 1810, then spread to Connacht and parts of Leinster, Ireland.
They were the most prevalent potato variety until they were almost wiped out by blight in 1845. In fact, 70 to 90% of potatoes being grown at the time of the potato blight in Ireland were Lumpers. Though their taste was inferior to other potatoes, the yield was very high. Other potatoes were less susceptible to the blight and were fine, but unfortunately it was Lumpers that were both vulnerable and the ones that the population relied on.
Most samples today of Lumper Potatoes actually come from those that survived in Scotland.
They were brought to America around 1994 by a man named Tom Stones, who cleared them for U.S. customs quarantine.