Birdsville Indigo (Indigofera linnaei
) is a flat, mat-forming, annual or perennial legume. It has many thin, hairy stems, and alternate pinnate, grey-green, hairy, oval shaped leaflets in two rows. I. linnaei
produces tight clusters of pinkish red pea-like flowers followed by groups of cylindrical seed pods. The plant is most abundant in pastures at the start of the summer wet season, when first rains stimulate growth of the plant.
All parts of I. linnaei
contain indospicine, a non-proteinogenic amino acid with hepatotoxic properties and beta-nitropropionic acid, a mycotoxin and potent mitochondrial inhibitor. Grazing on pastures containing I. linnaei
has been associated with the development of Indigofera toxicity