Helianthus laetiflorus var. subrhomboideus Helianthus rigidus subsp. subrhomboideus Helianthus laetiflorus var. subrhomboideus Helianthus rigidus subsp. laetiflorus Helianthus pauciflorus var. subrhomboideus Helianthus subrhomboideus Helianthus rigidus var. subrhomboideus
World Flora Online, accessed June 20, 2024