Or search: alga, chlorella, chlorophyte, cryptomonad
1 Syllable: S
Halle
2 Syllables: SU
alley, dally, galley, palsied, rallied, rallies, rally, sallied, sallies, sally, tallies, tally, valley
3 Syllables: USU
finale, verbally

Found 16 words across 3 groupings. Skipped 3 excess words of a similar stem.