A green man is a special kind of seventh son that is connected to "growing things." Henry, for example, is connected to the dandelion, Monmouth is connected to the aspen tree, Mordecai is connected to the grape vine, and Darius is connected to the mushroom.
Green men have a mark on their right palm that can be seen only with the second sight. This mark shows what sort of "green thing" they are connected to.
- "[Green men are] seventh sons that are connected to growing things. Green things. Like your dandelion....[and] my aspen tree."—Monmouth, p. 296 Dandelion Fire.
- "You're own mark [Henry]," he said, "is far more interesting. Rare, and one that I am fond of. I have seen it only once before...on the flesh of my cousin."—Ron, p. 167 Dandelion Fire.