Fig. 1: Reverse curvature and long tail of bodhi leaf enhanced water drainage efficiency.
From: Efficient agricultural drip irrigation inspired by fig leaf morphology
a Geographical distribution of five chosen species of the Ficus genus and average annual relative humidity in southeast Asia. The relative humidity map is reproduced21. Geographical distribution data of the Ficus genus is extracted from GBIF22. Bottom schematics are round, obtuse, acute, acuminate, and caudate leaf apex shapes. b Sketch of water drainage on demonstrated apex shapes at the same injection flow rate Q of 8.0 mL min−1 and the incline angle β of 60°. Drip frequency f (c) and drip volume Vd (d) of water droplets dripping from the apices. The caudate apex of bodhi leaf has the highest f and smallest Vd, revealing the highest drainage efficiency. e Optical image of a bodhi leaf with shape parameters, the radius of curvature along leaf margin R and r, the base width of leaf apex Wbase, the length of apex Lapex, and the total leaf length Ltotal. The statistics of reverse curvature r/R (f), long tail Lapex/Wbase, and Lapex/Ltotal (g) are based on the measurements of 76 natural bodhi leaves. In (f), Ф means the probability density of r/R in the statistics, and the purple dashed curve was the Gaussian fitting of the r/R histogram. Note that the left and right r/R values of natural bodhi leaves were separately measured and collected together. Thus, there were 76 × 2 = 152 leaves counted up in (f). The mean value of r/R is ~0.6. In (g), the black dashed ellipse was 95% confidence ellipse for the linear fitting. Data in (c) and (d) are shown as mean ± SD, and the error bar represents SD (n = 3 independent experiments). Source data for (c, d, f, g) are provided as a Source Data file.
