Anatomy of the shrimp plant, Justicia brandegeana (Acanthaceae)

Abstract

Justicia brandegeana is a popular ornamental plant in North America commonly known as the shrimp plant. In the wild, it grows as a shrub in semi-arid climates. Little is documented on the anatomy of this plant, therefore the purpose of this study was to determine the anatomy of the shrimp plant at the cellular level through various hand sectioning and staining techniques. It was determined that many anatomical features of this plant were synonymous to those of a typical dicotyledonous plant. However there were unique features of this plant that can be linked to its hot/dry environment such as a layer of suberized parenchyma in the stem surrounding the vascular tissue, a thick band of secondary xylem in the stem and root, phi thickenings in cortical cells just inside the exodermis in mature root, and expansion of the Casparian bands in the endodermis consistent with the secondary growth of the vascular tissue in the root. Further research is necessary on plants that have also adapted to semi-arid environments in order to compare and contrast the adaptations found in the anatomy of J. brandegeana.