Asteroid 39991, Iochroma, was discovered on April 20, 1998 by the Lincoln Laboratory Near-Earth Asteroid Research Team in Socorro, New Mexico. It has a period of 3 years, 301 days.
It was named for a genus of South American shrubs and small trees. Iochroma is Greek for "colored purple."
The iochroma flower (Iochroma cyanea)
Astrologically, asteroid Iochroma seems to have to do with the color purple, being purple-colored (e.g., angry).