NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information
(http://metchosinmarine.ca/gf/triglochin-maritima/)
“Seaside arrow-grass (Triglochin maritima) is a native plant found sporadically across Canada in saline, brackish, or fresh marshes and shores. This plant contains cyanogenic glycosides, which can release HCN during mastication by animals. Poisoning occurs primarily with ruminants, including cattle and sheep. The concentration of toxic chemicals increases during times of moisture depletion (Majak et al. 1980, Cooper and Johnson 1984, Poulton 1989).”