portion of meristem tissue primordium rwalls portion of primordium tissue (exact) 2010-11-15T09:10:22Z A primordium appears as a protrusion and is the first distinct form of a plant organ (PO:0009008), cardinal organ part (PO:0025001), or collective plant organ structure (PO:0025007). The transition from a primordium to the plant structure it develops into is marked by the development of non-meristematic cells, although meristematic cells may be present after the transition. plant_anatomy PO_GIT:186 portion of primordial tissue (exact) primordio (Spanish, exact) primordia (exact, plural) 原基（可視的） (Japanese, exact) A portion of meristem tissue (PO:0009013) that has as parts protoderm (PO:0006210) and sub-epidermal meristematic tissue and is committed to the development of a particular plant structure (PO:0009011). PO:0025127