In the UK the name of the flower is traditionally pronounced [name_u]DAY[/name_u]-lee-uh, which is how I say it.
[name_m]Just[/name_m] a quick note on written pronunciation, the American ‘‘doll’’ sound and British/Aussie ‘‘darl’’ sound are the equivalent of each other 
The inconsistency based on accent sometimes causes confusion so I thought I’d jump in.
I say day-lee-ah like the flower.
I say DAH-lee-uh, my mum says [name_u]DAY[/name_u]-lee-uh. We’re Brits. I have a cousin called DAH-lee-uh although I’m not actually sure of the spelling.
I’ve never actually heard this name spoken aloud and would assume Dah-lee-ah
It’s day.leah
I have always, always said DAHL-ee-uh (like doll and leah). I live in the US. Didn’t even know people pronounced it as day-lee-uh.
Me too.
I much prefer three syllables to two here. DAH-lee-uh as opposed to DAHL-ya
DAHL-yuh or DAH-lee-uh is how I would pronounce it.