Hi folks! I've got a real puzzler - this plant grows as a weed on empty/abandoned lots here. It gets absolutely huge (larger than small cars), has a pleasant lemon-chrysanthemum-resin scent, and the flowers superficially resemble those of Cannabis, although on closer inspection I'm pretty sure that the plant belongs to the Asteraceae. Locals call the plant "Marco" - this leads to Ambrosia artemisiodes in my Useful Plants of Ecuador book (which cites it as a strong insecticide against aphids and mites). Can anybody confirm this ID? When I search on the plant, it turns up in the flora of Chile but there's no mention of Ecuador, although it's rather widespread in the highlands. The only reference I can find for northern South America is for Ambrosia arborescens in Peru (which is at least closer than Chile), and I can't find any pictorial reference for it. Thanks!
The AAU Herbarium Database shows 4 records for Ambrosia artemisioides in Ecuador, with 2 as far north as Quito, so don't think you can rule it out from distribution. I've been finding lately from my Brugmansia research that the established norms on plant distribution, that are widely repeated by current authors with confident authority, don't really mean much at all. :)
