Where I live in the US (Minnesota) there are lots of different types of amaranth species. Most of them are considered weeds. One of the most common, particularly near agricultural settings in the upper Midwest, is waterhemp/rough fruit amaranth (Amaranthus tuberculatus).
Usually, if I see a plant I firmly believe is waterhemp, it is rarely on the CV’s list of candidate species, with its closest lookalike, Palmer amaranth listed instead. The number of research grade IDs for waterhemp pale in comparison to Palmer amaranth’s.
While it is indeed a close lookalike of waterhemp, Palmer amaranth is very rare in Minnesota, while waterhemp is almost ubiquitous. If Palmer is found here, it is treated as a serious noxious weed which requires reporting to governmental authorities.
Long story short, don’t be afraid to occasionally post weeds/plants you think are common.