Source : Webster's Revised Unabridged Dictionary (1913)

Dextrorsal \Dex*tror"sal\, Dextrorse \Dex"trorse`\, a. [L.
   dextrorsum, contr. fr. dextrovorsum, dextroversum, toward the
   right side; dexter right + versus, vorsus, p. p. of vertere,
   vortere, to turn.]
   Turning from the left to the right, in the ascending line, as
   in the spiral inclination of the stem of the common
   morning-gl['o]ry.

   Note: At present scientists predicate dextrorse or
         sinistrorse quality of the plant regarded objectively;
         formerly the plant was regarded subjectively, and what
         is now called dextrorse was then considered
         sinistrorse.

Source : WordNet®

dextrorsal
     adj : spiraling upward from left to right; "dextrorse vines" [syn:
            {dextrorse}]