SLz-axis *bulaklak
< *bujak + -CVC
'flower'
Data from Blust ACD | PWMP *bujak ‘flower’
Tagalog	bulak-lák ‘flower’
Casiguran Dumagat	buláklak ‘flower; to bloom’
Kapampangan 	bulaklák ‘flower’
Kapampangan	ma-mulaklák ‘to bloom’
Kapampangan	bulak-lák-an ‘a teen-agers game, played at wakes’
Pangasinan 	bulaklák ‘flower’
Hanunóo 	bulaklák ‘flowers in the decorative or ornamental sense’
Palawan Batak	buláklak ‘flower; hibiscus’
Note also:
Cebuano	bura-burák ‘flower’ < CVCV- + *bujak