Or search: dipnoi, ceratodus
2 Syllables: SU
bunches, cometh, frontage, lunches, monkish, plunges, punches, punish, sponges, tonnage, umbrage
3 Syllables: USU
consumptive, presumptive, unpunished

Found 14 words across 2 groupings. Skipped 1 excess word of a similar stem.