This short poem from Clark Ashton Smith (CAS) was published in his hometown newspaper in 1924, but never included in any of his published collections of verse. Likewise, it's not available on The Eldritch Dark, so here is the complete text:
Slowly the sorrow of the fallen leaf
Turns to desire for some undreamt-of blossom;
So love's implacable and sullen grief
Dies on an alien bosom.
There is sadness in these four lines that CAS deftly weaves with the imagery of "the fallen leaf" anticipating the death of a love "on an alien bosom." It's a small poem, but has a core of emotional rawness that is quite powerful.