Trientalis latifolia (Broadleaf Starflower) is a perennial herbaceous plant of the ground layer of forests in western North America. An herbaceous plant (in American botanical use simply herb) is a plant that has leaves and stems that die down at the end of the growing season to the soil level.They have no persistent woody stem above ground.y contrast, non-herbaceous perennial plants are woody plants which have stems above ground that remain alive during the dormant season and grow shoots the next year from the above-ground parts – these include trees, shrubs and vines.