Scientific Name: Sherardia arvensis

Common Name: field madder

Other Common Names: blue fieldmadder

Leaves: Whorled with 4 to 6 leaves at each node. Leaves are lanceolate to elliptic in outline, approximately 5 to 15 mm long and 2 to 4 mm wide. Leaves taper to a distinct tip and are hairy.

Identifying Characteristics: A prostrate winter annual with whorled leaves, square stems, and pink to purple flowers. Field madder is primarily a weed of turfgrass, lawns, and occasionally winter small grains. The square stems, whorled leaves, and pink to purple flowers are all characteristics that help in the identification of field madder. Field madder is often mistaken for either Smooth Bedstraw (<a href='../../weedimg/358'>Galium mollugo</a>) or catchweed bedstraw (<a href='../../weedimg/58'>Galium aparine</a>). However, the leaves of the bedstraws are generally larger and occur in whorls of 6 to 8 unlike field madder. Additionally, the leaves of field madder are more lanceolate and have much more of a distinct point than those of the bedstraw species.

Flower Seed Head: Stems: May be either prostrate along the ground (typical), erect, or prostrate with some tips ascending. Stems are square in cross-section and also hairy. Flowers: Occur in clusters at the ends of the stems. Individual flowers are 3 to 4 mm in length and pink to purple in color.

Where Found: This weed is distributed throughout the southern United States.

  • Life cycle: winter annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Rubiaceae

  • Leaf arrangement: whorled

  • Leaf shape: lance

  • Leaf margin: serrated

  • Ochrea: Not Present

  • Stem hairs: has hairs

  • Flower color: pink; blue; purple

  • Growth habit: upright and nonwoody

  • Stem: square or multi-edged

  • Leaf structure: simple

  • Leaf hairs: has hairs

  • Flower symmetry: bilateral symetry

  • Flower diameter: pencil

  • Leaf stalk: none