About Helianthus pauciflorus Nutt.
Helianthus pauciflorus Nutt., commonly known as the stiff sunflower, is a North American plant species belonging to the Asteraceae family. It is widely distributed across the Great Plains, Rocky Mountains, and Great Lakes region, and has become naturalized in scattered locations across the eastern United States and most of southern Canada, ranging from Alberta to Nova Scotia. Stiff sunflower is a perennial herb that grows to heights between 50 and 200 cm (1 ft 8 in – 6 ft 7 in), and spreads through underground rhizomes. Most of its leaves are attached close to the base of the stem. A single plant can produce 1 to 10 flower heads; each head holds 10 to 20 yellow ray florets that surround at least 75 red disc florets, though yellow disc florets occur less frequently. Hybrids between H. pauciflorus and H. tuberosus (Jerusalem artichoke) are named H. × laetiflorus. The name H. laetiflorus has additionally been used as a scientific synonym for H. pauciflorus. There are two recognized subspecies: Helianthus pauciflorus subsp. pauciflorus grows 80–200 cm (2 ft 7 in – 6 ft 7 in) tall, with alternate leaves near the tip of the stem that measure 8–27 cm (3 1⁄4–10 3⁄4 in) long and have acuminate, tapered-to-a-point tips. Helianthus pauciflorus subsp. subrhomboideus (Rydb.) O.Spring & E.E.Schill. grows 50–120 cm (1 ft 8 in – 3 ft 11 in) tall, with opposite leaves that measure 5–12 cm (2–5 in) long and have acute or obtuse tips.
