purpletop tridens (Tridens flavus) Tridens flavus, the purpletop tridens, red top, or greasegrass, is a large, robust perennial bunchgrass native to eastern North America. Source: https://www.inaturalist.org/observations/60007932 Related By Wade Hi. I’m Wade Murray, and like everyone with a personal website, mine is horribly, terribly out of date. On the Internet my handle is normally wademurray, but you can still find blime in some of the older dustier places. View all of Wade's posts.