Longitudinal sections of an aerial root tip (A–C) and of a flower bud (D–F). A and D, Sections documented by stereomicroscopy. B and E, Tissue prints of the sections in A and D, respectively, labeled with HSS-specific antibody. C and F, Tissue prints of the sections in A and D, respectively, labeled with preimmune serum. CC, Central cylinder; CR, callus on the labellum; GY, gynostemium (column); CP, cortex parenchyma; LA, labellum; OV, ovary; PC, procambium; PE, perigone; PO, pollinium; RC, root cap; ST, stigma. Size bars = 2 mm.