Incredibly useful paper on Phalaris and other grasses.
Parmar, S. S. (1974). TRYPTAMINE; LEVELS IN PASTURAGE IMPLICATED IN BOVINE PULMONARY EMPHYSEMA (Doctoral dissertation, University of British Columbia).
Out of 10 common pasture grasses, P. arundinacea was the only one that contained detectable amounts of tryptamines.
I want to share 2 interesting graphs
This shows there was a decline in tryptamine contents from August to October.
This shows there was in increase in tryptamine contents with an increase in nitrogen fertilizer. Ammonium sulphate increased tryptamine concentrations significantly more than urea, ammonium nitrate, sodium nitrate, and cynamid.