Answer: lupin

AnswerCrossword Clue
LUPINLeblanc's detective
lupinedible lupine seed
lupinany of a genus (Lupinus) of leguminous herbs including some poisonous forms and others cultivated for their long showy racemes of usually blue, purple, white, or yellow flowers or for green manure, fodder, or their edible seeds
lupina flowering plant, also LUPINE
LUPINHogwarts professor who was secretly a werewolf
LUPINLeblanc's Arsene
LUPINGentleman burglar Arsene
LUPINFictional burglar Arsene
LUPINFictional gentleman burglar Arsene
LUPINPlant of the pea family
LUPINPea-family plant
LUPINPurplish blue.
LUPINLeblanc's detective.
LUPINLeblanc's sleuth.
LUPINDetective Arsene.
LUPINBluebonnet.
LUPINBlue flower: var.
LUPINLandlady of Dicken's "Blue Dragon"
LUPINMaurice Leblanc's "Prince of Thieves" Arsene
LUPINLeblanc's gentleman burglar Arsene ..