Creeping indigo
Indigofera spicata
Fabaceae
Mainly planted for cover, green manure and erosion control in coffee, tea and rubber plantations in the tropics and subtropics. Medicinal uses. Green manure and soil stabilizer in agroforestry. Dye source.
Creeping indigo is a prostrate, herbaceous perennial plant with several stems radiating from a central woody stem. It is known to have a deep taproot, which is reported to reach at least 2 feet deep (see image). Creeping indigo has alternately arranged compound leaves ( 5-11 oblong leaflets, 5-25 mm long), while flowers are small pink or pinkish-orange and pea-shaped, and arranged in elongated clusters. Pods are narrow and cylindrical (15-25 mm long). It can reproduce by seed and vegetatively. Seed germination rates are low without scarification due to the hard seed coat. Plants send out trailing stems which can reach a length of 2-3 m. Rooting from nodes is also known to occur. It is a common weed of lawns, gardens, footpaths, roadsides, disturbed sites and waste areas. Heavy traffic areas, such as grass parking lots and/or heavily grazed pastures, may have an abundance of the weed. Creeping indigo is known to be poisonous to animals, with many reports of livestock and horse poisoning, as well feeding trials and field observation in the USA demonstrating that the plant was toxic for cattle, sheep, rabbits, pigs, Guinea pigs, horses and chicks). Similar to other plants in the family Fabacaea, it has the ability to fix atmospheric nitrogen.
Common pests of indigo plants (Indigo species) include root-knot nematodes, Arytaina punctipennis (psyllid), aphids, scale, mealybugs and spider mites. Flower visitation in the native Indigo species, Indigofera australis includes native bees, honey bees, wasps, flies, hoverflies, butterflies, moths and beetles (Wheen bee Foundation). Known insects of creeping indigo include Spodoptera littoralis (Egyptian cotton leafworm), Dichomeris ianthes (Alfalfa leaf tier) and Omiodes (Lamprosema) diemenalis (Soybean leaf roller).