A leaf lamina vein (PO:0020138) above the first order that is connected to another vein only at one end. [source: ISBN:9780801475184]
Comment
May be branched or simple. May be found inside a lamina areole. Usually used with third order or higher veins. If vein order is known, an additional annotation should be place on secondary vein (PO:0020140), tertiary vein (PO:0008021), quaternary vein (PO:0008022), or higher order vein (PO:0008023).