Upland White Goldenrod

Solidago ptermicoides (formerly Aster ptarmicoides)

White_Upland_Aster_Goldenrod_8-17-14.JPG

White upland aster goldenrod inflorescence in a prairie
Upland white goldenrod (Solidago ptarmicoides) used to be considered an aster because of its white, petal-like ray florets. It hybridizes with goldenrods and not with asters, however, so it is truly a goldenrod.
Other Common Name
White Upland Aster; Sneezewort Aster; Prairie Aster; White Flat-Top Goldenrod
Family

Asteraceae (daisies, sunflowers)

Description

Upland white goldenrod looks like an aster, with its flowerheads of white petal-like ray florets and pale yellowish disc florets. There are one to several upright stems arising from the short-branching roots. Perennial. Most leaves are basal or low on the stems; blades to about 8 inches long and ½ inch wide, rather thick and stiff, long-tapered to the base, short-stemmed or lacking a stem. toothless or sometimes with a few widely spaced teeth. Middle and upper stem leaves to about 3 inches long and very narrow. The flowerheads are arranged singly or in small clusters at tips of the plant, altogether forming a shallowly rounded or flat-topped cluster. There are 10–25 ray florets. The disc florets appear yellowish because of the protruding yellow stamens; the corollas (fused petals) are actually white. Blooms July–September.

Key Identifiers

This species differs from all other asters and goldenrods in the state in having both ray and disc florets with the corollas (the trumpet-shaped, fused petals) white.

Size

Height: to 20 inches.

White_Upland_Aster_Goldenrod_flowerhead_8-17-14.JPG

Closeup of upland white goldenrod flowerheads
Upland White Goldenrod
Upland white goldenrod differs from all other asters and goldenrods in Missouri in having both ray and disc florets with the corollas (the trumpet-shaped, fused petals) white. The protruding yellow stamens makes the disc part look pale yellow.

White_Upland_Aster_Goldenrod_side_8-17-14.JPG

Side view of upland white goldenrod growing in a prairie
Upland White Goldenrod (Sneezewort Aster)
Upland white goldenrod is scattered in the Ozark and Ozark Border divisions, in glades, blufftops, upland prairies, pastures, railroads, and roadsides. It blooms July–September.

White_Upland_Aster_Goldenrod_stem_8-17-14.JPG

Stem of upland white goldenrod
Upland White Goldenrod Stem
Most of the leaves on upland white goldenrod are basal or low on the stems. The middle and upper stem leaves reach about 3 inches long and are very narrow.
Habitat and conservation

Occurs in glades, blufftops, upland prairies, pastures, railroads, and roadsides.

Distribution in Missouri

Scattered in the Ozark and Ozark Border divisions.

Status

With its white, petal-like ray flowers and pale disc florets, upland white goldenrod is truly the oddball of the goldenrods: it looks much more like a white-flowered aster. It used to be considered an aster, but because it hybridizes with goldenrods and not with asters, its true genetic relationship is clear. Its change in taxonomic status is one reason there are so many different common names for this plant.

In addition to Aster ptarmicoides, another scientific name that has been used for this species is Oligoneuron album.

Note also that all of Missouri's "real asters" are no longer in genus Aster, either. Botanists have concluded that our New World asters are different enough (genetically) from the asters in the Old World that the should be separated from them. Therefore, all our native asters have been placed in separate genera. In Missouri, most of these are now in genus Symphyotrichum. The only true aster (in genus Aster) that grows wild in Missouri is a native of east Asia that escapes from gardens.

Human connections

The attractive clusters of flowers that appear in late summer make this a good native wildflower for naturalizing in dry locations.

The ancient creation stories of many human cultures usually say something about the Earth's amazing diversity of plants and animals, and sometimes these stories depict the early process of naming the many organisms. Our modern reclassification and renaming of this plant (and many others) is, in an odd way, a continuation of those narratives.

Ecosystem connections

Goldfinches eat the seed of this native wildflower.

Numerous insects visit the flowerheads for nectar, pollen, or both. Gall-forming wasps, aphids, and other insects may drink the sap or eat the stem or flowerhead base tissues. As with other extravagantly blooming composites of grasslands, the plant can become a mini-ecosystem in itself, as spiders, ambush bugs, and other predators lie in wait for unlucky insects to come near enough to capture.