Vegetative Anatomy of Theobroma cacao

Abstract

1. Some of the outstanding morphological features of Theobroma cacao are its chupon and orqueta formation, the basal and apical pulvini in petioles, and the flowering cushion. 2. The xylem of the primary root is hexarch, while that of the lateral roots is tetrarch. 3. Mucilaginous strands occur in all root tips, and mucilage-filled cells are common throughout the root system. 4. Chupon and fan woods are anatomically similar. 5. Elongated, mucilage-filled, lysigenous cavities occur in the pith throughout the shoot system, while shorter ones are very numerous in the cortex. 6. The chupon terminates in a five-branched orqueta. Anatomical examination shows a lack of internodal elongation between the nodes of these five branches. 7. There is only one bud to a leaf axil. 8. Spherical lysigenous cavities are common in the palisade layer of the leaf blade. The upper and lower epidermis are strikingly different. Stomata occur only in the lower epidermis, and the guard cells are very small. 9. A flowering cushion is derived from a solitary axillary bud.