Fig. 7. Nectaries and carpels of Aquilegia formosa flowers. (A) Owing to growth in the pedicel, the nectar spurs of Aquilegia formosa flowers, which develop from the abaxial side of the petals, point upwards (arrow). (B) As carpel (c) primordia emerge, AfCRC expression (B-F) is restricted to the abaxial side as seen in this flower. st, stamen; p, petal; se, sepal. (C) AfCRC expression precedes the emergence of carpels. As carpel primordia begin to elongate, AfCRC expression is excluded from the vasculature and restricted to cells adjacent to the vasculature (D,E). In developing carpels, AfCRC expression is specifically localized to a ring of cells surrounding the vasculature in the abaxial regions (E,F). (G) Anatomy of the carpel. Each of the five carpels is separate with ovules initiating from the margins of the carpels. AfCRC expression is excluded from the vasculature (arrow) but is expressed in cells surrounding it. (H,I) Anatomy of the nectar spur. The tip of the developing nectar spur consists of densely cytoplasmic parenchymatous cells, characteristic of nectary tissue (arrow in H). (J) No detectable AfCRC expression was observed in developing nectar spurs (arrow).