Helianthus pauciflorus aka Stiff Sunflower

Helianthus pauciflorus belongs to the aster family, Asteraceae. It is a perennial: it lives for more than one season. It returns each year, rather than dying after one season. Common names include stiff sunflower and prairie sunflower. Kew gives its native range as Canada into the northern and east-central United States. It grows in temperate regions, but is not native to Britain or Ireland. In the wild, it grows on prairies and other open ground. These sites range from dry to somewhat wet.

Plants For A Future gives its height as 5 feet [1.5 metres]. The source lists a spread of about 1 foot [0.3 metres]. It grows fast and can soon reach that size. The supplied evidence gives no more facts about this species’ leaves or stems. Nor does it describe this species’ flowers or fruit. The RHS page covers the genus, not these traits in this species. Those facts about the genus do not show its exact looks.

Grow this sunflower in full sun, in soil that drains well. Plants For A Future says it cannot grow in shade. It accepts sand, loam and clay, as well as soil with gravel. Soil can be mildly acid, neutral or mildly alkaline. The listed pH range is 6.1 to 7.8. It prefers dry to moist soil and can cope with drought. This makes it an option for beds that need little water. Plants For A Future lists USDA hardiness zones 3–7. The source also calls it easy to grow.

The plant has value in gardens grown for wildlife. Plants For A Future says it draws bees, butterflies or birds. It also suits dry gardens and food-forest planting. Grow new plants from seed, by division, or from herbaceous stem cuttings. Division means splitting plants; herbaceous cuttings use soft, non-woody stems. Sow seed straight into the ground outdoors in autumn. It seeds itself freely, so unwanted seedlings may grow. Bear this in mind when you choose its garden site.

The seeds offer an edible source of oil and protein. Plants For A Future includes this species in work on perennial oilseed crops. That work studies oilseed crops grown with other plants that live for several years. The source lists no known medicinal use or known hazard. No reports of harm do not prove safety for every use.