Transcription factor required for the initiation of nectary development. Also involved in suppressing early radial growth of the gynoecium, in promoting its later elongation and in fusion of its carpels by regulating both cell division and expansion. Establishes the polar differentiation in the carpels by specifying abaxial cell fate in the ovary wall. Regulates both cell division and expansion. Restricted to flowers, mostly in carpels and nectaries. Expressed at low levels in sepal primordia (buds), sepal receptacle and developing petal. Not detected in placental tissues, septum, stigma and ovules. In carpels, expression starts when the gynoecial primordia becomes distinct. First expressed in the lateral region of each carpel. Later resolves into two distinct domains, epidermal and internal. In epidermal tissues, mostly localized on the outer surface, successively from the base to the tip of the gynoecium and finally confined to the valve region before disappearing during last flowering stages. In internal tissues, first confined to four discrete zones adjacent to the future placental tissue occupying the full length of the elongating cylinder, declining from the apical regions and disappearing after the ovule primordia arise. Before nectaries initiation, expression occupies a ring of receptacle cells between the stamen and sepal primordia, from where nectaries will develop. Strongly expressed in nectaries until latest flowering stages. Down-regulated by SPT and by A class genes AP2 and LUG in the outer whorl. In the third whorl, B class genes AP3 and PI, and the C class gene AG act redundantly with each other and in combination with SEP1, SEP2, SEP3, SHP1 and SHP2 to activate CRC in nectaries and carpels. LFY enhances its expression. The double mutants crc-1 rbl-1, crc-1 sqn-4, and crc-1 ult1-4 exhibit strong floral meristem (FM) indeterminacy with reiterations of extra floral whorls in the center of the flower. Belongs to the YABBY family. Truncated N-terminus.