Due to increase in energy catastrophe and accompanying environmental issues, the search for renewable and alternative energy resources is a fiercely disputed problem in the scientific world. Biodiesel has proven to be the finest sustainable alternative to gasoline. Because of their environment‐friendly character and cost‐effectiveness, nonedible oil‐bearing seeds could be the possible resource for biodiesel production. Therefore, the present study uses scanning electron microscopy (SEM) to investigate and identify micromorphological features of six novel, nonedible oil‐bearing seeds of Verbenaceae as potential biodiesel feed stocks. Selected seeds of Verbenaceae range in size from 1 to 5 mm in width and 1.8 to 6.4 mm in length, according to light microscopic studies. The oil content of seeds ranges from14 to 19%. Seed texture, color, shape, size, periclinal and anticlinal wall patterns, and cell outline are all more variable in SEM‐mediated seed ultrastructure analyses. The findings of this work imply that SEM could be a useful method for revealing hidden micromorphological features in a variety of nonedible oil‐producing seeds, which could aid to future investigation, proper identification, seed categorization, and authenticity. These seeds were hard to be identified by the native people due to their resemblance in seed color and shape, so there is a need to give a detailed description of seed characters for proper identification of these plants. This work will determine the new features of the seeds, which will be helpful in near future.

Utilization of renewable and alternative energy feedstocks such as nonedible seeds oil to deal with the increasing energy crises and related ecological concerns have gained the attention of researchers. Biodiesel is an efficient and renewable substitute for diesel engine. This work investigates the potential of inexpensive nonedible seed oil of Linum usitatissimum to synthesize biodiesel using iron sulfate green nanocatalyst through the process of transesterification. Flax seed contains about 37.5% oil content estimated through Soxhlet apparatus. Light microscopy revealed that seed size varies from 3.0 to 6.0 cm in length, 2.0 to 3.3 cm in width, and 0.7 to 1.0 mm in diameter. Color of seed varied from yellow to brown. Characterization of biodiesel is performed through GC–MS and FTIR. Scanning electron microscopy was carried out to study the morphological features of seed coat. Catalyst was characterized by scanning electron microscopy, energy diffraction X‐ray, and X‐ray diffraction. The diffraction peaks of Fe3O4 green nanoparticles were found to be in 2θ values, 30.24°, 35.62°, 38.26°, 49.56°, 57.12°, and 62.78°. Fuel properties of biodiesel are also determined and compared with ASTM standards. Linum usitatissimum biodiesel has density 0.8722 (15°C kg/L), kinetic viscosity 5.45 (40°C cSt), flash point (90°C), pour point (−13°C), cloud point (−9°C), sulfur (0.0432% wt), and total acid number (0.245 mg KOH/g). It is concluded that L. usitatissimum seed oil is a highly potential source for biodiesel production to cope with the challenge of present energy demand.