Fig. 3

The absent erosion cell structures of archaeological woods from Nanhai No. 1 shipwreck. a Complete cell layer, cell wall remain intact and the very close connections between the cells (Sample 8, TEM). b The bordered pits (red arrows) and pit membrane (blue arrow) under higher magnification (Sample 8, TEM). c A bordered pit (red arrow) in a tracheid on the longitudinal section (Sample 20, SEM). d A bordered pit under high magnification, showed the pit membrane (yellow arrow) and the pit plug (red arrow) clearly (Sample 20, SEM). e The cross field pits on the tracheid (Sample 15, SEM). f Vessel pits from Sample 17 (SEM)