Cymbopogon citratus (DC.) Stapf. (lemongrass) is a widely used medicinal grass valued for its essential oils and diverse therapeutic properties; however, comprehensive pharmacogenetic documentation of the whole plant remains limited. The present study provides an integrated evaluation of the pharmacobotanical, antimicrobial, antioxidant, and chemical fingerprinting characteristics of C. citratus collected from the northeast coast of Tamil Nadu, India. Macroscopic and microscopic analyses established diagnostic features including sclerenchyma Tous vascular bundle sheaths, bulliform cells, dumb-bell-shaped silica bodies, prickle hairs, and annular vessels, providing robust anatomical markers for authentication. Physicochemical parameters (LOD, ash values, extractive values, pH) confirmed good-quality raw material with minimal foreign matter. The hydro-alcoholic whole-plant extract exhibited broad-spectrum antimicrobial activity, with pronounced inhibition against Staphylococcus aureus and Enterococcus faecalis. Potent antioxidant activity was recorded in the DPPH assay, with an IC₅₀ of 39.37 µg/mL, attributed to phenolic and flavonoid constituents. HPTLC profiling generated a reproducible chromatographic fingerprint with recurring marker bands at Rf 0.08, 0.04, and 0.01 under 254 nm and 366 nm, reflecting the chemical diversity of the extract. This study provides the first complete pharmacogenetic framework for C. citratus whole plant, offering essential baseline data for authentication, standardization, and future phytopharmaceutical development. Further studies on quantitative marker estimation, MIC/MBC analysis, and bioactivity-guided fractionation are recommended to strengthen its therapeutic applicability.