Euthamia caroliniana aka Coastal Plain Goldentop

Euthamia caroliniana, or slender goldentop, is in the aster family. This perennial herb comes from the eastern and northeastern United States. In North Carolina, it grows most on the coastal plain. It grows less often in the Piedmont. Wild plants grow by ditches and roadsides. They grow in wet, open spots in woods. They also grow near bogs and where soil drains poorly.

Plants reach 1–3 feet (0.30–0.91 m) tall. Clumps spread 1.5–2.5 feet (0.46–0.76 m) wide. Many upright stems form dense clumps of fine-textured leaves. The stems have angles and branch above their midpoint. Their surfaces may be smooth or have hairs. Narrow green leaves give the plant a grass-like look. Each simple leaf has smooth edges and one vein. Each leaf also has resin dots. Leaves grow at the base and alternate along the stems. The plant sheds its leaves each year.

Small yellow flower heads bloom from August through December. Each head looks like a tiny daisy. Many heads form dense, flat-topped groups at the stem tips. The branched flower display stands above the narrow leaves. You can cut these flowers through a long season. Bees come for nectar and pollen. Butterflies visit the flowers too. The plant has value for native bees. Its fruit is a cypsela, not a true achene. The fruit display lasts into winter.

Grow slender goldentop in full sun or part shade. It prefers acidic, sandy soil but accepts clay and loam. Neutral soil suits it too. Choose moist soil or ground that gets wet at times. The source says it copes with drought. Yet it warns against dry soil. Its stated hardiness range spans USDA zones 3 through 10. It copes with packed soil and resists deer. These traits suit pond edges, stream banks, and bog margins. Other uses include meadows and native gardens. Plantings that support pollinators also suit it.

Slender goldentop grows fast and spreads through rhizomes, or underground stems. This spread forms clumps but can make it weedy. Divide plants every two to three years to limit growth. You can also raise more plants through division. Remove faded flowers to help spur more blooms. The plant needs a moderate level of care. Few insects or diseases cause problems. Leaf rust does occur at times.