Tony:
Once I found the scientific name of the angel's trumpet I stopped looking, but alga's answer caused me to look further. I thought the scientific classification of plants was cut and dried. Not so. The datura is the group to which most flowers commonly called angel's trumpet belong. That's part of the problem: more than one flower is called angel's trumpet. Some sources list the brugmansia as a datura, others deny it. One web site even said that brugmansia was the true angel's trumpet, and that the common name of the various datura was devil's trumpet. So, I can't even establish which flower Wolfe had in mind. In the flower language the generic datura means "deceitful charms", but I can find nothing more specific and have no way of knowing if that is what Wolfe intended. Sorry.
Does anyone know what the "purple creeper you're so proud of" Agia told the curator in the Botanic Gardens she had seen growing wild on a hillside in Cobblers Common might be? (I, XIX)
Roy