Cleistanthus collinus[2] is a plant species first described by Roxburgh, with its current name after Bentham and Hooker; it is included in the family Phyllanthaceae.

[3] Cleistanthus collinus (Karra) contains a plant poison also called oduvan (Tamil), kadise (Kannada), Vadisaku (Telugu), Oduku (Malayalam) and Gaja Madara (Sinhala) .

Ingestion of its leaves or a decoction of its leaves causes hypokalemia (kaliuresis and cardiac arrhythmias),[5] metabolic acidosis, hypotension and hypoxia[6] probably due to distal renal tubular acidosis, ARDS and toxin induced vasodilatation respectively.

[7][8][9] Hypokalemia and acidosis probably also induces rhabdomyolysis resulting in myoglobinuric kidney failure and neuromuscular weakness.

[10] Its effects are probably mediated by injury to the distal renal tubules, pulmonary epithelium and peripheral blood vessels due to glutathione depletion[11] (animal studies have shown benefit with N-acetylcysteine).