The only thing I think the column misses is that the classic ‘Old West Tumbleweed’ is not an Amaranth, but rather Russian Thistle (Salsola Tragus) It’s an invasive that was introduced in the 1870s from Russian flax shipments and rapidly colonized the midwest and west. Hollywood directors, being ignorant of botany and not particularly caring about historical accuracy saw the Russian thistle that had become ubiquitous across the west by the time of moving pictures, assumed it was always there and thought it made a pretty sight. So, in answer to ‘Where does tumbleweed come from?’ The answer is Russia. 
They’ve graduated from invading us with tumbleweeds to invading our political system. Impressive. LOL