Figure 5: General decline of major vein density with increasing leaf size.
From: Developmentally based scaling of leaf venation architecture explains global ecological patterns
The trend observed across species for the Panamanian rainforest trees. The micrograph drawings are traces of regions of the lamina with 2° and 3° veins, matched with leaf silhouettes for given species, all to the same scale, thus showing the greater spacing between major veins in larger leaves. Minor veins (not shown) do not show correlation of spacing or scaling with leaf size across species. The Calophyllum longifolium leaf has exceptional venation, with parallel 2° veins branching from the midvein and transverse 3° veins. This rare exception shows that the general venation-scaling pattern, so typical across species, can be broken, given very strongly different venation development. For Calophyllum, the 2° veins development shows similarity to that of minor veins in typical dicotyledonous leaves (see Supplementary Table S2).
