Over the land freckled with snow half-thawed
The speculating rooks at their nests cawed
And saw from elm-tops, delicate as flower of grass,
What we below could not see, Winter pass.
Edna Longley (editor), Edward Thomas: The Annotated Collected Poems (Bloodaxe Books 2008).
In her comment to the poem, Edna Longley notes that the phrase "delicate as flower of grass" was also used by Thomas in a prose piece titled "Flowers of Frost": "The beeches that were yesterday a brood of giantesses are now insubstantial and as delicate as flowers of grass." Ibid, page 285.
As I have noted before, Michael Longley is an admirer of Edward Thomas's poetry. Thus, it may not be merely a coincidence that he has also written a four-line poem titled "Thaw."
Snow curls into the coalhouse, flecks the coal.
We burn the snow as well in bad weather
As though to spring-clean that darkening hole.
The thaw's a blackbird with one white feather.
Michael Longley, The Echo Gate (1979).
Longley's poem is an excellent companion piece to Thomas's poem: his poem looks inward; Thomas's poem looks outward. And "freckled" becomes "flecks." And the "rooks" turn into "a blackbird." But the same territory -- be it inward or be it outward -- is explored by both poets.