The accumulation of the spermine alkaloid aphelandrine was studied in Aphelandra tetragona roots during one growth cycle using analytical HPLC. Highest aphelandrine accumulation with 7 mg g-1 dry wt and 9 mg g-1 dry wt was observed in root tissue 16 and 26 weeks after planting. Just before flower formation, the aphelandrine content in the roots decreases indicating remobilization of the alkaloid. An enzymatic degrading system for aphelandrine was also found in root tissue. 2(3H)-Benzoxazolinone and 6-methoxy-2(3H)-benzoxazolinone are liberated when the integrity of root cells is destroyed. © 1993.