Aster family (Asteraceae)
Description: This native perennial wildflower is about 1½3' tall and either unbranched or sparingly so. The central stem usually leans over to one side; it is glabrous and light green while young, but becomes glaucous and blue-grey or burgundy-grey with age. Along the central stem and any side stems there are alternate leaves up to 5" long and 1" across; these leaves become gradually smaller as they ascend upward. They are medium to dark green, lanceolate-oblong, elliptic, or narrowly ovate in shape, more or less serrated along their margins, mostly hairless, and sessile. The upper surface of each leaf has a prominent central vein and faint side veins.
At the axils of the middle to upper leaves, there develops small clusters of flowerheads. Each flowerhead is about 1/8" across or a little larger; it has 4-5 yellow ray florets and a similar number of golden yellow disk florets. At the base of the flowerhead, there are small green bracts (phyllaries) with obtuse tips. Sometimes, the central stem will terminate in a short narrow inflorescence. This inflorescence consists of flowerheads that are closely bunched together along with some small leafy bracts. The blooming period occurs from late summer into the fall and lasts about 3-4 weeks. Each fertile floret is replaced by a small bullet-shaped achene that is finely pubescent; at its apex, there is a small tuft of hairs. The achenes are distributed by the wind. The root system is fibrous and rhizomatous. Occasionally, small loose colonies of plants will develop from the rhizomes.
Cultivation: The preference is medium shade to partial sun, mesic to dry-mesic conditions, and a soil that is loamy or somewhat rocky. During dry weather, some of the lower leaves may wither away, otherwise they usually remain in good condition and resist disease.
Range & Habitat: Blue-Stemmed Goldenrod is occasional in the far eastern, southern, and west central areas of Illinois, but rare or absent elsewhere. This species is more common in Indiana and other eastern states. Habitats include upland woodlands, woodland openings, bluffs, upper slopes of ravines, and rocky cliffs in shaded or partially shaded areas. This species is usually found in higher quality habitats.
Faunal Associations: The nectar and pollen of the flowers can attract a wide variety of insects, especially short-tongued bees, wasps, and flies. The caterpillars of many species of moths feed on goldenrods (see Moth Table). Blue-Stemmed Goldenrod is one of the host plants of the leaf beetle Microrhopala xerene and the leafhopper Prescottia lobata. The seeds of goldenrods are eaten sparingly by the Indigo Bunting, Slate-Colored Junco, Tree Sparrow, and other songbirds. White-Tailed Deer are especially likely to feed on the foliage of goldenrods in woodlands.
Photographic Location: A rocky upland woodland in west-central Indiana.
Comments: This distinctive goldenrod is both elegant and shade-tolerant. Of the many goldenrod species that occur in Illinois, only two species produce primarily axillary clusters of flowers: Blue-Stemmed Goldenrod and Zigzag Goldenrod (Solidago flexicaulis). Both of these goldenrods are typically found in woodlands. Zigzag Goldenrod has much wider leaves (exceeding 1¼" across) that are ovate and coarsely serrated; the leaves of this latter species have petioles, while the leaves of Blue-Stemmed Goldenrod are sessile. Blue-Stemmed Goldenrod often has glaucous stems that are blue-grey or burgundy-grey, while the stems of Zigzag Goldenrod are light green.