Webster's 1828 Dictionary
DEXTRORSAL
a.Rising from right to left, as a spiral line or helix.
Webster's 1913 Dictionary
DEXTRORSAL; DEXTRORSE
Dex *tror "sal, Dex "trorse `, a. Etym: [L. dextrorsum, contr. fr. dextrovorsum, dextroversum, toward the right side; dexter right + versus, vorsus, p. p. of vertere, vortere, to turn. ]
Defn: Turning from the left to the right, in the ascending line, as in the spiral inclination of the stem of the common morning-glóry.
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.
The Wordsmith Dictionary