Riddells Goldenrod, Solidago riddellii, is a somewhat rare native goldenrod which occurs only in wet meadows. Features tiny, bright yellow flowers borne in dense, erect, flat-topped, terminal, corombose inflorescences atop stiff, glabrous stems typically growing 3-4 feet tall. Flowers bloom late summer to early autumn. Narrow, lance-shaped, linear leaves. Goldenrods have been wrongly accused of causing hay fever which is actually an allergic reaction to wind-borne pollen from other plants such as ragweed.
The blooming period occurs from early to mid-autumn for about 3 weeks. Afterwards, the florets are replaced by achenes with sessile tufts of white hair. These achenes are 1.5–2 mm. long, bullet-shaped, slightly flattened, and vertically ribbed. The root system consists of a thickened rootstock with fibrous roots – on older plants, the rootstock may form a caudex. Sometimes rhizomes are also produced, forming clonal offsets.
Habitats include moist dolomite prairies, gravelly hillside seeps, fens, and low areas along springs. This goldenrod occurs in higher quality wetland habitats.
Easily grown in wet soils in full sun. Remove spent flower clusters to encourage additional bloom.