Read "Yerba Buena" at The Eldritch Dark:
The Spanish title of this poem by Clark Ashton Smith (CAS) can be translated as "good herb", a term which has been applied to plants in many parts of the world, particularly those in the mint family.
Given CAS' home in the Sierra Nevada foothills of California, I suspect the poem refers to Clinopodium douglasii, which is commonly known as "yerba buena" and is found throughout the Golden State.
The poem is a pantoum, a form that CAS rarely used. It makes for an interesting technical exercise, but the use of iambic tetrameter creates short lines, which don't really play to CAS' strengths as a poet. Nonetheless, "Yerba Buena" does effectively establish a sense of place and experience:
Still wafts a perfume wild and sweet—
Crushed by the limbs and breasts of love
Within that place where laurels meet
Amid the ocean-fronting grove.
If the poem can be taken as something of a tribute to the state of California itself, it certainly works as a celebration of the simple beauties of the author's home.