Good news for those of us who try to look up the wildflowers we see. My favorite identification site is back up at http://www.missouriplants.com. This site has good pictures and descriptions of around 1000 Missouri wildflowers and plants. All you need to know is the color and leaf arrangement to look through the gallery and identify your wildflower.
Silene stellata W.T. Aiton
June to September N Family: Caryophyllaceae
Flower: The open white flower has a swollen calyx surrounded by five green sepals behind it. The five petals are narrow where they join it then flare out into deeply fringed fans. The stamens and pistil are on a green bulge of ovary in the center. Open groups or panicles of flowers are on long petioles from several slender flower stalks branching off the end of the main stem.
Leaf: The stem leaves are in whorls of four sessile leaves. The leaves are triangular with the bases meeting around the stem then tapering to a sharp point. There is a prominent midvein.
Stem: The unbranched stem is green and hairy. The stem forms a plum colored knob on top of each leaf node. Several flower stalks go off near the top of the stem. It can reach over three feet tall but often arches over.
Root: The perennial root is thick and branched.
Habitat: This plant likes light shade and moist soil as is found at the edges of woods, along steams, ravines and roadside ditches.
Starry Campion is easy to overlook when it struggles through surrounding vegetation. The arching flower stalks with their white flowers is what is seen first.
In more open and favored places the growing stalk raises curiosity. It is stout and grows straight up three to four feet. The whorls of four leaves surround the stem at intervals. On top of each whorl is a swollen reddish knob making the whole appear as though constructed in pieces.
The flowers are easy to identify because of the five white fringed fans held stiffly out from a light green urn as long as the petals. The flowers don’t open at the same time but overlap enough to put on a display. They open late in the day to attract moths for pollination and close in a day or two unless the weather is hot and closes them sooner.
New stalks and flowers are produced over the summer as long as the plant remains in the shade and gets sufficient moisture. In the wild the stems are gradually buried by slender vines twining their way up. By the end of summer only the flower stalks and flowers still stick out to show where the plant is growing.
Like other flowers in the Pink family, Starry Campion is easy to grow, slow to become established but puts on a large show in a few years. Each taproot can put out several stems so the effect is massed in a clump.