sinistrorse

[,sɪnɪ'srɔs]

sinistrorse (adj.): 1856, a word wanted by the botanists to describe the direction of spiral structures in nature, from Latin sinistrorsus "toward the left side," from sinister "left" (see sinister). It was paired with dextrorse but confusion over what was the proper point of view to reckon leftward or rightward spiraling prevented the word being as useful as it might have been.