Soursop (Annona muricata L.) is a well-known species for indigenous use of medicines. This work aimed to determine the selected features including idioblasts in different-aged leaves of A. muricata. Leaf samples were collected and prepared for light microscopy. Numerous non-glandular trichomes are restricted to only the abaxial surface of hypostomatic and dorsiventral leaves. The 1st leaf is slightly different in histological structures than those of the 3rd and 8th leaves. Two kinds of foliar idioblasts were observed: subspherical idioblasts and calcium oxalate crystal-containing idioblasts. Carbohydrate and fat were detected in all leaf stages but more were observed in the 1st leaf. No protein was detected in any of the leaves and the 8th leaf exhibited the highest pigment contents. Further studies of subspherical idioblasts relating acetogenins will be necessary to determine and confirm the localization in all plant parts.
