B.W.van Ee, P.E.Berry & Ginzbarg (Small) 2009 - Ee BV, Berry PE, Ginzbarg S (2009) An Assessment of the Varieties of Croton glandulosus (Euphorbiaceae) in the United States. Harvard Papers in Botany 14: 45-59. doi: 10.3100/025.014.0109.
There is no corrections for Croton glandulosus var. arenicola yet.