Plants of the Eloise Butler Wildflower Garden

Stiff Goldenrod is an erect native perennial, the unbranched stem, which can be from 1 to 5+ feet high, is downy and frequently with a reddish color with age.

The leaves are grayish-green, stiff at maturity, oval, hairy, with the lower basal ones long-stalked with a shallow groove on the stalk facing upward; the upper alternate leaves are stalkless or with extremely short stalks; margins may be slightly serrate. Leaves within the floral array become bracts. Late season new basal rosette leaves frequently persist through the winter.

The floral array is a grouping of branched clusters, large for the size of the plant, corymbiform in shape, that is - somewhat flat-topped - and the whole thing up to 10 inches wide. Stalks of the cluster and the individual flowers are hairy.

Flowers: Each small composite flower has 6 to 13 fertile (pistillate) yellow ray florets and a central disc up to 1/3 inch wide of 14 to 36 bisexual florets with yellow corolla tubes which have 5 lobes at the throat that are erect to spreading when open. The rays are very short - 1.4–5.4 × 1.2–1.9 mm in size. The disc florets have 5 stamens with yellow anthers. The stamens tightly surround the single style which is branched with a triangular appendage on the tip of each branch and greatly exserted from the corolla when the floret opens. The phyllaries (bracts) surrounding the outside of the flower head are in 3 to 4 series, oblong, of unequal length, appressed, have a green midrib with 3 to 5 pronounced nerves and rounded tips. The stalk of the flower has fine hair.

Seeds are ribbed dry cypselae, 0.8–1.7 mm long, obconic in shape (inverted cone) with a fluffy pappus for distribution by wind. Seeds of Solidago usually require 60 days of cold stratification and light for germination.

Varieties: There are 3 accepted subspecies of the species - details at bottom of page.

Habitat: Stiff Goldenrod grows well in dry sandy places and prairies that have full to partial sun with dry to moderate moisture. Too much water and rich soil is detrimental. It is fairy drought tolerant. The root system is a fibrous branching woody caudex. It grows easily from stratified seeds to produce plants the same season. It also self-seeds. If you have to move the plant, you can take offshoots from the root system.

Names: The common name and the species name, rigida, refer to the stiffness of the leaves. The genus name Solidago, is from the Latin solidare, as the plants of this genus were known to "make whole". (see bottom of page). The author name for the plant classification - 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.

Botanists have recently reclassified many members of the Aster family. Some, beginning with G. L. Nesom, have placed Stiff Goldenrod into the genus Oligoneuron from Solidago. The Oligoneurons have unbranched hairy stems and flat-topped clusters of bright yellow flower heads. However some major authorities such as Flora of North America (Ref. #W7) have raised objections to the reclassification and believe the species should be in Solidago Linnaeus sect. Ptarmicoidei, which consists of six species that have, among their traits, flat-topped arrays and persistent basal leaves. The issue is not settled. Minnesota authorities which usually follow the Flora, have also left it in Solidago.

Comparisons: Regardless of the scientific debate, you are unlikely to confuse this species with another in our area. The tall unbranched stem with the flat-topped clusters of goldenrod type flowers is distinctive.