genus of plants from North Am,erica grown for their showy red white pink or purple spring blooms

[tikkit]

this is the last clue in my crossword, the letters I have are :
- H - O -

[chairobyx16]

Probably Phlox

[tikkit]

Thanks Chairobyx, I'd have never got that by guessing!
I can send it off now,prize is a days cooking course with Hugh Fearnley=Whittingstall!