AmTide MSM 60 DF Herbicide is labeled for bur buttercup when used as directed on the product label.
AmTide MSM 60 DF Herbicide is not labeled for artillery fern and we are unable to find a product that is labeled for it. A glyphosate based product like RoundUp QuickPro might kill it as is it a non-selective herbicide that generally kills anything to which it is applied.
Amtide MSM 60 DF can be applied to St Augustine though you should note some chlorosis or stunting of the turfgrass may occur following the application. Amtide is labeled to control dollarweed though a second application may be required after 4-6 week for complete control. Amtide is not labeled to control violets. The only selective herbicide that can be used on St Augustine and is labeled for both violets and dollarweed that comes to mind is Image 70DG.