Beta-1,3-xylosidase that hydrolyzes beta-1,3-xylooligosaccharides to D-xylose. Hydrolysis of successive xylose residues from the non-reducing termini of (1->3)-beta-D-xylans. Inhibited by Ag(+), Cu(2+), Hg(2+), Mn(2+), Pb(2+), Zn(2+) and p-chloromercuric benzoic acid. Optimum pH is 7.0. Optimum temperature is 35 degrees Celsius. Belongs to the glycosyl hydrolase 43 family.