In recent years, the rapid development of wireless technologies has led to the widespread adoption of the Internet of Things (IoT) in various fields. One of the fastest-growing segments of IoT is the “smart” wearables sector. In the next few years, the development of flexible plant-wearable devices that can provide vital information about the physiological characteristics of plants will be essential to support the faster growth of precision agriculture. We propose a small (overall size Ø35 mm × 0.8 mm), ultra-lightweight (0.4 g), and elegant-shaped antenna for unobtrusive integration on a plant surface for application in IoT-based precision agriculture at ISM 2.45 GHz band. The radiating element has a design that resembles a dragonfly, making the antenna visually unnoticeable. We used ZZ Plant leaves as the substrate for the antenna and transparent polymer foil for encapsulating the conductive parts, achieving a highly flexible, waterproof, and chemically resistant antenna for application in harsh environments. The obtained results indicate that the antenna is resilient to changes in substrate relative permittivity up to ±20%. It exhibits high radiation efficiency (between 26% and 40%) and omnidirectional patterns across the ISM 2.45 GHz band. Moreover, the measured results align reasonably well with the simulated ones.