leaf lamina vein leaf vein primary leaf vein Generally the largest and most prominent of the leaf veins. A leaf may have more than one primary vein. The central primary vein is the midvein (PO:0020139). Vein orders only apply to hierarchically branching vein patterns, not to dichotomously branching vein patterns, as found in some ferns and gymnosperms. A leaf lamina vein (PO:0020138) that connects directly to a petiole vascular system (PO:0000052) or a shoot axis vascular system (PO:0000039). plant_anatomy vena primaria de la hoja (Spanish, exact) PO:0025413 一次葉脈 (Japanese, exact) rwalls PO_GIT:435 2012-02-01T04:24:58Z