This 20 to 45 cm tall plant has a spindly stem. Its leaves resemble those of large-flowered trillium, but have a shorter stalk. The flower has 3 wavy petals that are narrower than those of large-flowered trillium.
This plant grows 20 to 45 cm tall. It has a more upright bearing than other trilliums (its stem is erect). As its name indicates, several of its parts are grouped in threes, including its large, broadly ovate leaves and its solitary flower with 3 dark red petals.