Two new isocarbostyril alkaloids, 7-deoxypancratistatine and pancratiside (= pancratistatine-2-O-β-d- glucoside), were isolated from the resting bulbs of Haemanthus kalbreyeri. The structures of the two alkaloids were established by comprehensive spectral analyses and chemical transformations. The plant growth regulatory profile of these two alkaloids and three other isocarbostyril congeners, narciclasine, 7-deoxynareiclasine, and pancratistatine, is appraised. Haemanthus kalbreyeri provides a new source of the anti-tumour alkaloid, pancratistatine. © 1989.