The dried bark of a genus of trees, Aspidosperma quebrachoblanco; white quebracho (family Apocynaceae); has been used as a respiratory stimulant in emphysema, dyspnea, and chronic bronchitis; the two chief alkaloids are aspidospermine and quebrachine. [Port. quebrahacho, fr. quebrar, to break, + hacha, axe, referring to the hardness of the wood]
