I'd consider Phalaris to be a reliable source of 5-MeO-DMT at this point. My patch is yielding around 100 mg per square foot per month outdoors, or I've grown material indoors that's 5x as strong (but the growth rate may be slower, not sure). The extraction is more work than MHRB, cactus, etc., but still feasible with basic equipment. The extract is usually consumed as the crude resin, but at least three people have independently crystallized 5-MeO-DMT from Phalaris.
DMT is still a research project, though. 5-MeO-DMT is toxic enough that most impurities are safer per unit weight, so that incomplete purification or unexpected variation in the natural alkaloid profile will result in disappointment rather than poisoning. That's not true for DMT and multiple people have reported serious incidents, especially in combination with harmalas. I think there's promise, but I'd want pretty long experience before I took ayahuasca from allegedly DMT-dominant Phalaris.
I sampled a leaf from a natural stand of Phragmites australis. It had a peak at the same RT as DMT, but the largest other peak was ~50x as big by UV fluorescence area, not too promising. I understand it's usually extracted from the rhizome and not leaf, but I've never sampled the rhizome.