³Doric,² indeed. Although there is no pressing reason to think Van (or VN)
had this image in mind, Beardsley¹s work was well-known in Petersburg art
circles of the Silver Age.  And then there is Beardsley College in Lolita.

The image from Beardsley's illustrations for Lysistrata is not a column, but
a herm, earlier a free-standing stone (phallic), later a statuary
border-marking depicting the god Hermes, armless shoulders often decked with
floral tributes and originally with genitalia, though usually not quite so
flagrantly as Beardsley's. The description from Ada does certainly sound
like a Beardsley image, though. This sounds like a clue to the artist's
signature: 
‹ a black aster (evolved from a blot)
 though I don't recognize it.

The Getty Museum has a gorgeous bronze herm (complete) a photo of which I
will try to send attached.

Carolyn