classic waka stream

麓まで尾の上の桜散り来ずは
たなびく雲と見てや過ぎまし
Roma-ji

Fumoto made onoe no sakura chirikozu wa tanabiku kumo to mite ya sugimashi

English Translation
If the summit's bloom
did not come falling this far
down to the foothills
I would take them for trailing
cloud, and pass them by unseen
Meaning
If the cherry from the ridge had not come drifting down as far as the foot of the hill, I should have taken it for trailing cloud and gone on past.
Commentary
Book Two Spring Poems II 124

Headnote: when he wrote ten poems on blossom.
The conceit is that the fallen petals themselves prove the white on the ridge to be blossom and not cloud. The headnote assigns the poem to a set of ten on blossom.
The poet, given by his court title, is Fujiwara no Akisuke (1090-1155). He compiled the Shika Wakashu and built the poetics of the Rokujo house. Fujiwara no Kiyosuke, the poet of the thirty-fourth poem in Book One, was his son.
The time is when the cherries fall; the place is the foot of a mountain.
The occasion was the writing of the ten poems.

The first line means as far down as the foot of the hill, and takes it as given that petals have reached there.
The second line uses the same word for a ridge as the hundred and twenty-second poem.
The third line is a supposition: had they not come drifting down.
The auxiliary at the close marks a contrary-to-fact case, with an interrogative particle: in fact the petals arrived and the matter was settled, but had they not, he would have gone past thinking it cloud.
Whether a white thing is cloud or blossom is the subject of the hundred and second and hundred and fifteenth poems as well. Those state the impossibility of telling; this one has the evidence of fallen petals and reaches an answer, so that the question is placed here in its resolved form.
Author
Fujiwara no Akisuke
Source
Shin Kokin Wakashu
Other