This Wednesday’s Weed is sweet flag, Acorus calamus. It’s native to Asia and was introduced to North America for its supposed medical purposes, but it’s actually probably poisonous. It does have a sweet scent when damaged, however. They grow commonly in mucky, stagnant water, and can take over entire clearings, as seen in the second picture.
The name “sweet flag” comes from the sweet scent and the fact that the leaves resemble those of irises (which used to commonly be called “flags”, which is still seen in the common name yellow flags). Interestingly enough, yellow flags’ scientific name, Iris pseudacorus, means “false Acorus”, so the two plants are essentially named for each other in different ways.










