Clark Ashton Smith (CAS) commented on this poem in a letter to August Derleth from 1943:
Here's a poem (Strange Girl). The girl claimed to be a cousin of Jack London and a niece of the late Henry Van Dyke--a combination of blood-strains that would drive anyone to the devil!
This poem relates a more earthy romantic encounter than we typically see from the pen of CAS, and the letter excerpt quoted above indicates that it was based on a real person.
Although the poem contains the sort of references to classical mythology that often feature in CAS' love poems, he uses those elements sparingly, as in the fourth stanza:
Upon the delicate chin you turned
Venus had set her cloven sign.
Like embers seen through darkest wine
Your unextinguished tresses burned.
Overall, "Strange Girl" is quite a passionate ode to an apparently brief encounter, ending with the creation of a undeniably strong bond:
Sister you seemed to all the woe
My heart has known but never sung. . . .
Was it for this your fingers clung
To mine, as loath to let me go?
It's quite a bit more moving than CAS' more grandiose verses of romance, with the action located in a "familiar bar" rather than a bucolic woodland hideaway. Even with his predilection for formal, metrical poetry, CAS could still write verse with a contemporary feel, and "Strange Girl" is an excellent example of that.
*See letter #292 in Eccentric, Impractical Devils: The Letters of August Derleth and Clark Ashton Smith published by Hippocampus Press.