trifid bur marigold

NOUN
19 LETTERS · STARTS WITH T

trifid bur marigold is a valid 19-letter word worth 27 points in Scrabble and 32 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1R1I1F4I1D2B3U1R1M3A1R1I1G2O1L1D2
1 + 1 + 1 + 4 + 1 + 2 + 0 + 3 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 2 + 1 + 1 + 2 =27 PTS
DOUBLE WORD → 54TRIPLE WORD → 81
MEANING

What does trifid bur marigold mean?