- marsh + wort (Wiktionary)
“You may believe it,' said Cuchulainn; 'if a flock of birds come to the plain, you shall have a duck with half of another; if fish come to the estuaries, you shall have a salmon with half of another; a sprig of watercress, and a sprig of marshwort, and a sprig of seaweed, and a drink of cold sandy water after it.”
“You shall have the three sprigs, the sprig of watercress, and the sprig of marshwort, and the sprig of seaweed.”
“Welcome, O friend Fergus,' said Cuchulainn; 'if a fish comes into the estuary, you shall have it with half of another; if a flock comes into the plain, you shall have a duck with half of another; a spray of cress or seaweed, a spray of marshwort; a drink from the sand; you shall have a going to the ford to meet a man, if it should happen to be your watch, till you have slept.”
These user-created lists contain the word ‘marshwort’.
I have in mind the worts associated with a green thumb rather than a green beer - but as you can see by the name, I'll accept anything you have to offer.
Another of my random palavery lists for terms and phrases that don't fit into any of my other lists.
Looking for tweets for marshwort.