With its white, petal-like ray florets and pale disc florets, upland white goldenrod is truly the oddball of the goldenrods: it looks like a white-flowered aster. Indeed, it used to be considered an aster.
Upland white goldenrod is a perennial wildflower with one to several upright stems arising from the short-branching roots.
The flowerheads are arranged singly or in small clusters at the tips of the plant, altogether forming a shallowly rounded or flat-topped cluster. Flowerheads have 10–25 white ray florets. The disk florets appear yellowish because of the protruding yellow stamens, but their small corollas (fused petals) are actually white.
Blooms July–September.
The leaves are alternate; most leaves are basal or low on the stems; the blades can be about 8 inches long and ½ inch wide; they are rather thick and stiff, long-tapered to the base, short-stemmed or lacking a stem. toothless or sometimes with a few widely spaced teeth. The middle and upper stem leaves reach about 3 inches long and are very narrow.
Similar species: Upland white goldenrod differs from all other asters and goldenrods in the state in having both ray and disk florets with the corollas (the trumpet-shaped, fused petals) white.
Height: to 20 inches.
Scattered in the Ozark and Ozark Border divisions.
Habitat and Conservation
Occurs in glades, blufftops, upland prairies, pastures, railroads, and roadsides.
Status
Native Missouri wildflower.
Human Connections
The attractive clusters of flowers that appear in late summer make this a good native wildflower for naturalizing in dry locations.
When you find one of these remarkable, oddly pale wildflowers and learn about it, it's a wonderful small discovery.
The ancient creation stories of many human cultures usually say something about the Earth's amazing diversity of plants and animals, and these stories often depict humans' 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 seeds 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 wildflowers that produce large displays of flower clusters, this 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.
Upland white goldenrod sure isn't a typical goldenrod. 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 and scientific 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 native asters are no longer in genus Aster, either. Botanists found that our New World asters are different enough (genetically) from Eurasian asters that they split them away into new genera. In Missouri, most of these former-true-asters 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.
