Rayless sunflower (Helianthus radula)
Click on terms for botanical definitions.
Rayless sunflower is a unique member of the Helianthus or sunflower genus. Like most sunflowers, its flowerhead includes a compact but relatively large center comprised of many small, maroon to dull brown disk florets. But unlike its relatives, its ray florets are almost entirely absent, hence the common name “rayless.” (Some specimens do produce a few small, yellow ray florets.) Each plant typically produces a single flowerhead. Basal leaves are thick and rounded with rough, hairy surfaces. Stem leaves are short, narrow and hairy. Stems are also hairy.
Rayless sunflower typically blooms late spring into early fall. It occurs naturally in sandy uplands, along moist to dry roadsides, and in seasonally wet savannahs and pine flatwoods. It attracts a variety of pollinators.
Family: Asteraceae (Composite or daisy family)
Native range: Panhandle, most of Central and North Florida, and Collier County
To see where natural populations of rayless sunflower have been vouchered, visit florida.plantatlas.usf.edu.
Hardiness: Zones 8a–9b
Soil: Seasonally moist to dry, sandy soils
Exposure: Full sun
Growth habit: 1-2′ tall
Garden tips: Although not as striking as its relatives, rayless sunflower is a great addition to a home pollinator garden. It is easily adaptable to a variety of conditions and will attract butterflies as well as other pollinators. It does best in open, sunny areas.