Tephrosia purpurea

Tephrosia purpurea is a flowering plant in the pea family, Fabaceae, growing in poor soils as a common wasteland weed with a pantropical distribution. It is native to south-western Asia (the Levant, Arabian Peninsula, Socotra, Iran, Pakistan, India and Sri Lanka) and north-eastern Africa. It has silky, obovate-oblong leaflets, purple flowers that are at their best in January, and pods holding six or seven brownish seeds. It grows in deep soils in semi-arid and wadi areas, and its deep roots store moisture so that it survives drought. In Oman and the United Arab Emirates it has been used to treat bronchitis, cough, earache, nasal congestion, wounds and bone fractures. It makes indigo-like dyes, which gave it the name Egyptian indigo, and the Bedouin of Sinai and the Negev make hot drinks from its leaves and those of other plants. The page says it is toxic to goats.