Abstract: A telescopic stick for a shortenable umbrella having at least two telesco parts guided in one another so as to be secure against relative twisting or rotation about their longitudinal axes; the two parts being provided with complementary polygonal profile or cross-section; the polygonal profile comprising at least 10 facets which embellish the umbrella stick and improve its jewel-like appearance while functioning to prevent relative rotation and preserving stability of operation as the stick is telescoped from an umbrella "open" to "closed" condition; at least one of the facets of the polygonal cross section having a concave or convex curvature in the circumferential direction.