Euphorbia peplus L.
Euphorbia: for Euphorbus, corpulent Greek physician of Juba II, King of Mauretania. Juba, educated in Rome, and married to daughter of Antony and Cleopatra. From eu, "good" and phorbe, "pasture or fodder," thus giving euphorbos the meaning "well fed."
peplus: One source has peplum as a gown or coat, from the Greek, and another gives peplis as a name used by Dioscorides as a Mediterranean coastal spurge and peplus as a name he used for the northern equivalent of peplis