Nine alkaloids of the β-carboline type have been isolated from Banisteriopsis caapi Morton (Malpighiaceae). Two new alkaloids of a different structural type, shihunine and dihydroshihunine, are reported here. The former had been isolated earlier from Dendrobium lohohense Tang. and Wang., and D. pierardii Roxb.; this is the first recorded natural occurrence of the latter, which possesses the S configuration. © 1982, American Chemical Society. All rights reserved.