Trees & Shrubs of the Eloise Butler Wildflower Garden

Meadowsweet is a native erect deciduous shrub with an unbranched stem, growing to six feet in height. Twigs have a yellowish-brown bark, older stems are brown to reddish-brown. There are two varieties.

The leaves are alternate, stalked, varying from a narrow lanceolate shape to more broadly obovate, 3 to 5 times longer than wide, up to 3-1/2 inches long. Bases are wedge shape to rounded, margins are finely to coarsely toothed depending on the variety. There is a main mid-vein with many pinnate laterals (which are not prominent), some laterals ending at a primary tooth. Some leaves many be doubly toothed. Leaf surfaces are mostly smooth.

The inflorescence is a terminal panicle, sometimes narrowly conical and sometimes open depending on the variety. The panicle height is up to 3.5 times the diameter. Additional panicles can rise from the upper leaf axils. Branches within the inflorescence usually have fine short hair. The flower clusters are quite showy.

The flowers are 5-parted with a hemispherical shaped hypanthium which has 5 lobes, broadly triangular at the tips. The outside surface of these lobes may be smooth or fine fine hair. Buds may be tinged with pink. The petals are  white, spreading outward, circular in the upper half, then narrowed to the base. Flowers are about 1/4 inch wide. The central receptacle is of 5 carpels, each with a greenish pistil and style. Stamens number 30 to 50, are 1 to 2 times the petal length and are exserted. Filaments are white, anthers are brownish in pollination. There may be up to 4 false stamens (staminodes). There is a colorful nectary ring at the base of the stamens that is yellow to orangish-pink.

Fruit: Fertilized flowers produce a 5-parted smooth capsule of 5 smooth seed follicles, 3 to 4 mm long, each typically containing 2 to 4 small seeds, then opening at the tip for seed dispersal. Seeds are very small and light and need to be surface sown and require 60 days of cold stratification. Fruits provide no winter interest.

Varieties: Two - Var. alba has longer leaves, 3 to 4 times the width, more narrow, with finely toothed margins and an inflorescence that is narrowly conical. Var. latifolia has shorter leaves, 2 to 3 times the width, more elliptical, coarse teeth on the margins and open pyramidal inflorescences. This variety is usually taller overall. The photos shown here are of var. alba.

Habitat: Meadowsweet is found in moist soils with wet to wet-mesic conditions; full to partial sun such as found in wet prairies, open ground along streams, marshy areas. Constant moisture is needed. Dead-heading may produce additional bloom. Shaded plants do not flower.

Names: The genus Spiraea is from the Greek speiraira, a plant used for garlands. The base of this is speira, meaning a spiral or twisted, as in making a garland. The species name alba means 'white' and the variety name latifolia means broad referring to the more elliptical leaf. The author name for the plant classification, from 1772 - ‘Du Roi’ refers to Johann Philipp Du Roi (1741-1785), German physician and botanist who published work on North American trees. His major work was Dissertatio inauguralis observationes botanica. See notes at page bottom about the common name.

Comparisons: Both varieties exist in Minnesota. One is likely to run into the European species, S. salicifolia, which has been imported into North America as an ornamental and thus when it escaped cultivation, it hybridized with S. alba, producing difficult to identify plants. These might typically be found in developed areas and near abandoned gardens. Also found in Minnesota is S. tomentosa. Steeplebush, which looks similar but has pink flowers, hairy seed follicles, far fewer stamens.