Phalaris arundinacea and Phalaris aquatica, as well as Phalaris brachystachys, are known to contain the alkaloids N,N-DMT , 5-MeO-DMT, and 5-OH-DMT.
Some research has been done into the variability of alkaloids in the Phalaris grasses. Strains with high levels of alkaloids are best avoided in locations with grazing cattle and sheep, due to potential toxicity. Such high-alkaloid strains include Phalaris Aquatica AQ-1 and the species Phalaris brachystachys. Seasonal and weather patterns also appear to affect alkaloid concentration, as most toxicity occurs in autumn and in times of drought. Regrowth after grazing or mowing also shows a considerable increase in alkaloids.
| Species | | | | |
| Phalaris aquatica | | | | |
| Phalaris arundinacea | | |||
| Phalaris brachystachys | | | ||
None of the above alkaloids are said to have been found in P. californica, P. canariensis, P. minor and hybrids of P. arundinacea together with P. aquatica.