The violet in the wood, that's sweet to-day,
Is longer sweet than roses of red June;
Set me sweet violets along my way,
And bid the red rose flower, but not too soon.
Ah violet, ah rose, why not the two?
Why bloom not all fair flowers the whole year through?
Why not the two, young violet, ripe rose?
Why dies one sweetness when another blows?

Augusta Davies Webster

http://www.poemhunter.com/poem/the-violet-and-the-rose/