"A measurable or observable characteristic of a cellular component (GO:0005575), biological process (GO:0008150) or molecular function (GO:0003674) that is part of, or has participant a plant anatomical entity (PO:0025131) and/or a plant structure development stage (PO:0009012)." [GO:0003674, GO:0005575, GO:0008150, Gramene:pankaj_jaiswal, PO:0009012, PO:0025131, TO:cooperl]