Madder family (Rubiaceae)
Description: This herbaceous perennial plant is about ½–1½' tall, often branching abundantly and presenting a bushy appearance. The weak stems are ascending to sprawling; they are light green, sharply 4-angled, shallowly furrowed along their sides, and mostly glabrous, except where the whorled leaves occur. Near the bases of these leaves, there are narrow rings of dense short hairs on the stems. At intervals along these stems, there are whorls of 4-6 sessile leaves. Where the lower stems branch dichotomously, there are usually whorls of 5-6 leaves, otherwise there are whorls of 4 leaves. Relative to their stems, these leaves are ascending to widely spreading. Individual leaves are ½–1¼" long and about one-fourth as much across; they are elliptic-oblong to oblong in shape, while their margins are entire (toothless) and stiffly ciliate. The upper and lower leaf surfaces are medium green and mostly glabrous. However, the lower leaf surfaces are stiffly short-hairy along their central veins. These hairs can cling for support on adjacent plants.
The upper and outer stems terminate in dichotomously branched clusters of 2-4 flowers; there are 1-2 small clusters of 2-4 flowers per stem. The glabrous peduncles of these floral clusters are up to 1" long and the glabrous pedicels of the flowers are up to ½" long. Each flower is a little less than ¼" across, consisting of a white corolla with 4 lanceolate lobes, a pair of pistils, and 4 stamens; the calyx is minute and insignificant. The inferior ovaries of the pistils are light green, and glabrous; together they are biglobular in shape. The blooming period occurs from late spring to mid-summer, lasting about 1 month. Usually only a few flowers are in bloom at the same time. After the blooming period, the ovaries mature into a pair of joined dry fruits; each fruit contains a single seed. The seeds are about 0.5 mm. long, somewhat flattened, and globoid. The root system is fibrous.
Cultivation: The preference is full sun to light shade, wet to moist conditions, and soil containing organic matter. This plant doesn't like to dry out, and it slowly fades away after blooming.
Range & Habitat: The native Wild Madder is an occasional to locally common plant that has been reported from most counties of Illinois. However, it is uncommon or absent in some central and western counties of the state (see Distribution Map). Habitats include wet to moist black soil prairies, prairie swales, floodplain woodlands, soggy thickets, swamps, fens, seeps, and shallow ditches along railroads. This plant tends to occur in grassy or sedge-dominated areas and it functions as an understory plant in wet to moist prairies. However, with the destruction of such prairie habitat, it has become less common than in the past.
Faunal Associations: Generally, the small white flowers of Wild Madder (Galium obtusum) and other bedstraws (Galium spp.) attract small bees and flies, including Halictid bees, masked bees (Hylaeus spp.), and Syrphid flies. These insects cross-pollinate the flowers. Some insects feed destructively on the foliage and other parts of bedstraws. These species include flower-feeding larvae of the Bedstraw Midge (Dasineura americana), foliage-feeding larvae of an introduced sawfly (Halidamia affinis), and the larvae of such moths as the Galium Sphinx (Hyles gallii), Drab Brown Wave (Lobocleta ossularia), and White-banded Toothed Carpet (Epirrhoe alternata). Bedstraws are also summer hosts of the polyphagous Black Cherry Aphid (Myzus cerasi). Little is known about the floral-faunal relationships of Wild Madder with vertebrate animals.
Photographic Location: The photographs were taken at a moist prairie remnant along an abandoned railroad in Champaign County, Illinois.
Comments: Except for the showy Northern Bedstraw (Galium boreale), bedstraws (Galium spp.) are often overlooked by prairie restorationists and wildflower enthusiasts because of their small flowers. Wild Madder can be distinguished from other bedstraws by the following characteristics: 1) it has smooth hairless stems, 2) there are usually only 4 leaves per whorl, although sometimes 5-6 leaves per whorl, 3) the fruits are smooth and hairless, 4) the flowers have 4 corolla lobes, and 5) the leaves are blunt-tipped. Other bedstraws often have bristly stems and fruits, more than 4 leaves per whorl, flowers with 3 corolla lobes, and/or leaves with more pointed tips. Another common name of Galium obtusum is Blunt-leaved Bedstraw.