Flowers preach to us if we will hear:—
The rose saith in the dewy morn:
I am most fair;
Yet all my loveliness is born
Upon a thorn.
The poppy saith amid the corn:
Let but my scarlet head appear
And I am held in scorn;
Yet juice of subtle virtue lies
Within my cup of curious dyes.
The lilies say: Behold how we
Preach without words of purity.
The violets whisper from the shade
Which their own leaves have made:
Men scent our fragrance on the air,
Yet take no heed
Of humble lessons we would read.
But not alone the fairest flowers:
The merest grass
Along the roadside where we pass,
Lichen and moss and sturdy weed,
Tell of His love who sends the dew,
The rain and sunshine too,
To nourish one small seed.

Christina Georgina Rossetti

http://www.poemhunter.com/poem/consider-the-lilies-of-the-field/