Beauty and Beauty's son and rosemary -
Venus and Love, her son, to speak plainly -
born of the sea supposedly,
at Christmas each, in company,
braids a garland of festivity.
Not always rosemary -

since the flight to Egypt, blooming indifferently.
With lancelike leaf, green but silver underneath,
its flowers - white originally -
turned blue. The herb of memory,
imitating the blue robe of Mary,
is not too legendary

to flower both as symbol and as pungency.
Springing from stones beside the sea,
the height of Christ when he was thirty-three,
it feeds on dew and to the bee
"hath a dumb language"; is in reality
a kind of Christmas tree.

Marianne Moore

http://www.poemhunter.com/poem/rosemary/