Someone found this in Mexico and I was hoping someone could get an ID on this wonderous plant so I could help them out.
Here is their description;
"Small plant with broad leaves and fluffy white flowers. Growing out of the rocks along the river banks."
And the area it was growing was "Tropical forest, dry season, Chorreadero Park, 10 km above Chiapa de Corzo, Chiapas, Mexico."
You could also try this: http://www.tropicos.org/SpecimenGeoSearch.aspx
zoom in on southern Mexico until Chiapa de Corzo is visible, paste Ageratum in the genus field and enter. What comes up are all the historical collections for the genus in the area. click on the green dots brings up the herbarium collection info and click on it to bring up the entry. I click the latin name of the plant and then I highlight the name and right click and "search google". It'll give you a targetted search for the region.
I have these flowers as part of my photographic collection for the last two years. When I photoed at the conservatory, it didn't have a label or id tag so I was wrong for the last two years. Of all the mistflowers, I think B. sordida looks like the images provided by Vineworld.
The photo that i linked in is from Lincoln Park Conservatory...possibly they are mistaken in their ID .The plant in DG plant files ID'd as B sordida shows a marked difference in bloom appearance, but there is a white form that appears very close to VineWorld's original post.
The plants does not seem to be B. sordida mainly because invlucre bracts are sharp and spreading, plant seems to be too small (and flowering) for what is shrub that can grow up to 15 feet tall, also the flower-heads form a large spreading inflorescence.